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45:
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2147:. During the last years this type of gauge became much more user friendly and easier to operate. In the past the instrument was famous for requiring some skill and knowledge to use correctly. For high accuracy measurements various corrections must be applied and the ball must be spun at a pressure well below the intended measurement pressure for five hours before using. It is most useful in calibration and research laboratories where high accuracy is required and qualified technicians are available. Insulation vacuum monitoring of cryogenic liquids is a well suited application for this system too. With the inexpensive and long term stable, weldable sensor, that can be separated from the more costly electronics, it is a perfect fit to all static vacuums.
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induce errors in the results as the movement of the air pressure is trying to force the diaphragm to move in the opposite direction. The errors induced by this are small, but can be significant, and therefore it is always preferable to ensure that the more positive pressure is always applied to the positive (+ve) port and the lower pressure is applied to the negative (-ve) port, for normal 'gauge pressure' application. The same applies to measuring the difference between two vacuums, the larger vacuum should always be applied to the negative (-ve) port. The measurement of pressure via the
Wheatstone Bridge looks something like this....
1360:: Force-balanced fused quartz Bourdon tubes use a spiral Bourdon tube to exert force on a pivoting armature containing a mirror, the reflection of a beam of light from the mirror senses the angular displacement and current is applied to electromagnets on the armature to balance the force from the tube and bring the angular displacement to zero, the current that is applied to the coils is used as the measurement. Due to the extremely stable and repeatable mechanical and thermal properties of fused quartz and the force balancing which eliminates most non-linear effects these sensors can be accurate to around 1
1322:: Strain gauge based pressure sensors also use a pressure sensitive element where metal strain gauges are glued on or thin-film gauges are applied on by sputtering. This measuring element can either be a diaphragm or for metal foil gauges measuring bodies in can-type can also be used. The big advantages of this monolithic can-type design are an improved rigidity and the capability to measure highest pressures of up to 15,000 bar. The electrical connection is normally done via a Wheatstone bridge, which allows for a good amplification of the signal and precise and constant measuring results.
1347:
1543:
37:
1816:, a diaphragm, a capsule, or a set of bellows, which will change shape in response to the pressure of the region in question. The deflection of the pressure sensing element may be read by a linkage connected to a needle, or it may be read by a secondary transducer. The most common secondary transducers in modern vacuum gauges measure a change in capacitance due to the mechanical deflection. Gauges that rely on a change in capacitance are often referred to as capacitance manometers.
1857:
1869:. The positioning of the indicator card behind the pointer, the initial pointer shaft position, the linkage length and initial position, all provide means to calibrate the pointer to indicate the desired range of pressure for variations in the behavior of the Bourdon tube itself. Differential pressure can be measured by gauges containing two different Bourdon tubes, with connecting linkages (but is more usually measured via diaphragms or bellows and a balance system).
3303:
4677:
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132:
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1392:. Generally, this technology is considered to provide very stable readings over time. The squeeze-film pressure sensor is a type of MEMS resonant pressure sensor that operates by a thin membrane that compresses a thin film of gas at high frequency. Since the compressibility and stiffness of the gas film are pressure dependent, the resonance frequency of the squeeze-film pressure sensor is used as a measure of the gas pressure.
1126:
4639:
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3349:. A Casagrande piezometer will typically have a solid casing down to the depth of interest, and a slotted or screened casing within the zone where water pressure is being measured. The casing is sealed into the drillhole with clay, bentonite or concrete to prevent surface water from contaminating the groundwater supply. In an unconfined aquifer, the water level in the piezometer would not be exactly coincident with the
2217:
resistors. The excitation to the bridge is applied via a constant current. The low-level bridge output is at +O and -O, and the amplified span is set by the gain programming resistor (r). The electrical design is microprocessor controlled, which allows for calibration, the additional functions for the user, such as Scale
Selection, Data Hold, Zero and Filter functions, the Record function that stores/displays MAX/MIN.
3295:
1960:
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1825:
140:
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1334:. This technology is employed in challenging applications where the measurement may be highly remote, under high temperature, or may benefit from technologies inherently immune to electromagnetic interference. Another analogous technique utilizes an elastic film constructed in layers that can change reflected wavelengths according to the applied pressure (strain).
4453:
1760:
2990:
Valves. PTC 19.2 provides instructions and guidance for the accurate determination of pressure values in support of the ASME Performance Test Codes. The choice of method, instruments, required calculations, and corrections to be applied depends on the purpose of the measurement, the allowable uncertainty, and the characteristics of the equipment being tested.
200:, fluid levels (by comparing the pressure above and below the liquid) or flow rates (by measuring the change in pressure across a restriction). Technically speaking, most pressure sensors are really differential pressure sensors; for example a gauge pressure sensor is merely a differential pressure sensor in which one side is open to the ambient atmosphere. A
1118:
4701:
4501:
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atmosphere to measure gauge pressure, open to a second port to measure differential pressure, or can be sealed against a vacuum or other fixed reference pressure to measure absolute pressure. The deformation can be measured using mechanical, optical or capacitive techniques. Ceramic and metallic diaphragms are used. The useful range is above 10
2332:
2541:
Additional wires at cathode potential in the line of sight between the ion collector and the grid prevent this effect. In the extraction type the ions are not attracted by a wire, but by an open cone. As the ions cannot decide which part of the cone to hit, they pass through the hole and form an ion beam. This ion beam can be passed on to a:
834:
235:, gauge pressure measurement prevails. Pressure instruments connected to the system will indicate pressures relative to the current atmospheric pressure. The situation changes when extreme vacuum pressures are measured, then absolute pressures are typically used instead and measuring instruments used will be different.
2194:
284:, where atmospheric pressure changes will have a negligible effect on the accuracy of the reading, so venting is not necessary. This also allows some manufacturers to provide secondary pressure containment as an extra precaution for pressure equipment safety if the burst pressure of the primary pressure sensing
2993:
The methods for pressure measurement and the protocols used for data transmission are also provided. Guidance is given for setting up the instrumentation and determining the uncertainty of the measurement. Information regarding the instrument type, design, applicable pressure range, accuracy, output,
2952:
When fluid flows are not in equilibrium, local pressures may be higher or lower than the average pressure in a medium. These disturbances propagate from their source as longitudinal pressure variations along the path of propagation. This is also called sound. Sound pressure is the instantaneous local
2646:
order of metres. In ambient air, suitable ion-pairs are ubiquitously formed by cosmic radiation; in a
Penning gauge, design features are used to ease the set-up of a discharge path. For example, the electrode of a Penning gauge is usually finely tapered to facilitate the field emission of electrons.
2450:
version, an electrically heated filament produces an electron beam. The electrons travel through the gauge and ionize gas molecules around them. The resulting ions are collected at a negative electrode. The current depends on the number of ions, which depends on the pressure in the gauge. Hot cathode
1896:
Force-balanced fused quartz
Bourdon tube sensors work on the same principle but uses the reflection of a beam of light from a mirror to sense the angular displacement and current is applied to electromagnets to balance the force of the tube and bring the angular displacement back to zero, the current
1864:
In practice, a flattened thin-wall, closed-end tube is connected at the hollow end to a fixed pipe containing the fluid pressure to be measured. As the pressure increases, the closed end moves in an arc, and this motion is converted into the rotation of a (segment of a) gear by a connecting link that
1806:
gauges are based on a metallic pressure-sensing element that flexes elastically under the effect of a pressure difference across the element. "Aneroid" means "without fluid", and the term originally distinguished these gauges from the hydrostatic gauges described above. However, aneroid gauges can be
1717:
is too high. When measuring liquid pressure, a loop filled with gas or a light fluid can isolate the liquids to prevent them from mixing, but this can be unnecessary, for example, when mercury is used as the manometer fluid to measure differential pressure of a fluid such as water. Simple hydrostatic
1364:
of full scale. Due to the extremely fine fused quartz structures which are made by hand and require expert skill to construct these sensors are generally limited to scientific and calibration purposes. Non force-balancing sensors have lower accuracy and reading the angular displacement cannot be done
345:
conducted experiments with mercury that allowed him to measure the presence of air. He would dip a glass tube, closed at one end, into a bowl of mercury and raise the closed end up out of it, keeping the open end submerged. The weight of the mercury would pull it down, leaving a partial vacuum at the
181:
is zero-referenced against ambient air pressure, so it is equal to absolute pressure minus atmospheric pressure. A tire pressure gauge is an example of gauge pressure measurement; when it indicates zero, then the pressure it is measuring is the same as the ambient pressure. Most sensors for measuring
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These methods are designed to assist in the evaluation of measurement uncertainty based on current technology and engineering knowledge, taking into account published instrumentation specifications and measurement and application techniques. This
Supplement provides guidance in the use of methods to
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These gauges use the attraction of two magnets to translate differential pressure into motion of a dial pointer. As differential pressure increases, a magnet attached to either a piston or rubber diaphragm moves. A rotary magnet that is attached to a pointer then moves in unison. To create different
2011:
Indicator needle axle. This has a spur gear that engages the sector gear (7) and extends through the face to drive the indicator needle. Due to the short distance between the lever arm link boss and the pivot pin and the difference between the effective radius of the sector gear and that of the spur
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in a sensing mechanism to measure stress, or changes in gas density, caused by applied pressure. This technology may be used in conjunction with a force collector, such as those in the category above. Alternatively, resonant technology may be employed by exposing the resonating element itself to the
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Likewise, cold-cathode gauges may be reluctant to start at very low pressures, in that the near-absence of a gas makes it difficult to establish an electrode current - in particular in
Penning gauges, which use an axially symmetric magnetic field to create path lengths for electrons that are of the
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is inserted in the vacuum chamber directly, the pins being fed through a ceramic plate in the wall of the chamber. Hot-cathode gauges can be damaged or lose their calibration if they are exposed to atmospheric pressure or even low vacuum while hot. The measurements of a hot-cathode ionization gauge
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246:
readings can be ambiguous without the proper context, as they may represent absolute pressure or gauge pressure without a negative sign. Thus a vacuum of 26 inHg gauge is equivalent to an absolute pressure of 4 inHg, calculated as 30 inHg (typical atmospheric pressure) − 26 inHg
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Piezometers in durable casings can be buried or pushed into the ground to measure the groundwater pressure at the point of installation. The pressure gauges (transducer) can be vibrating-wire, pneumatic, or strain-gauge in operation, converting pressure into an electrical signal. These piezometers
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Maintenance cycles of cold cathode gauges are, in general, measured in years, depending on the gas type and pressure that they are operated in. Using a cold cathode gauge in gases with substantial organic components, such as pump oil fractions, can result in the growth of delicate carbon films and
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The low-pressure sensitivity of hot-cathode gauges is limited by the photoelectric effect. Electrons hitting the grid produce x-rays that produce photoelectric noise in the ion collector. This limits the range of older hot-cathode gauges to 10 Torr and the Bayard–Alpert to about 10 Torr.
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to 10 Torr. Ionization gauge calibration is very sensitive to construction geometry, chemical composition of gases being measured, corrosion and surface deposits. Their calibration can be invalidated by activation at atmospheric pressure or low vacuum. The composition of gases at high vacuums
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The shape of the sensor is important because it is calibrated to work in the direction of air flow as shown by the RED arrows. This is normal operation for the pressure sensor, providing a positive reading on the display of the digital pressure meter. Applying pressure in the reverse direction can
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resistors. An additional laser-trimmed resistor is included to normalize pressure sensitivity variations by programming the gain of an external differential amplifier. This provides good sensitivity and long-term stability. The two ports of the sensor, apply pressure to the same single transducer,
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patented his gauge in France in 1849, and it was widely adopted because of its superior simplicity, linearity, and accuracy; Bourdon is now part of the Baumer group and still manufacture
Bourdon tube gauges in France. Edward Ashcroft purchased Bourdon's American patent rights in 1852 and became a
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Liquid-column gauges consist of a column of liquid in a tube whose ends are exposed to different pressures. The column will rise or fall until its weight (a force applied due to gravity) is in equilibrium with the pressure differential between the two ends of the tube (a force applied due to fluid
337:
claimed that all things are made of air that is simply changed by varying levels of pressure. He could observe water evaporating, changing to a gas, and felt that this applied even to solid matter. More condensed air made colder, heavier objects, and expanded air made lighter, hotter objects. This
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are the most sensitive gauges for very low pressures (also referred to as hard or high vacuum). They sense pressure indirectly by measuring the electrical ions produced when the gas is bombarded with electrons. Fewer ions will be produced by lower density gases. The calibration of an ion gauge is
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that separates regions of different pressure. The amount of deflection is repeatable for known pressures so the pressure can be determined by using calibration. The deformation of a thin diaphragm is dependent on the difference in pressure between its two faces. The reference face can be open to
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If the fluid being measured is significantly dense, hydrostatic corrections may have to be made for the height between the moving surface of the manometer working fluid and the location where the pressure measurement is desired, except when measuring differential pressure of a fluid (for example,
892:(Hg) and water; water is nontoxic and readily available, while mercury's density allows for a shorter column (and so a smaller manometer) to measure a given pressure. The abbreviation "W.C." or the words "water column" are often printed on gauges and measurements that use water for the manometer.
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at sea level, but is variable with altitude and weather. If the absolute pressure of a fluid stays constant, the gauge pressure of the same fluid will vary as atmospheric pressure changes. For example, when a car drives up a mountain, the (gauge) tire pressure goes up because atmospheric pressure
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Barometric pressure sensors can have an altitude resolution of less than 1 meter, which is significantly better than GPS systems (about 20 meters altitude resolution). In navigation applications altimeters are used to distinguish between stacked road levels for car navigation and floor
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The
American Society of Mechanical Engineers (ASME) has developed two separate and distinct standards on pressure measurement, B40.100 and PTC 19.2. B40.100 provides guidelines on Pressure Indicated Dial Type and Pressure Digital Indicating Gauges, Diaphragm Seals, Snubbers, and Pressure Limiter
2536:
is proportional to the gaseous molecule density multiplied by the electron current emitted from the filament, and these ions pour into the collector to form an ion current. Since the gaseous molecule density is proportional to the pressure, the pressure is estimated by measuring the ion current.
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This is an over-simplified diagram, but you can see the fundamental design of the internal ports in the sensor. The important item here to note is the "diaphragm" as this is the sensor itself. Is it slightly convex in shape (highly exaggerated in the drawing); this is important as it affects the
238:
Differential pressures are commonly used in industrial process systems. Differential pressure gauges have two inlet ports, each connected to one of the volumes whose pressure is to be monitored. In effect, such a gauge performs the mathematical operation of subtraction through mechanical means,
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equals total vacuum). Most gauges measure pressure relative to atmospheric pressure as the zero point, so this form of reading is simply referred to as "gauge pressure". However, anything greater than total vacuum is technically a form of pressure. For very low pressures, a gauge that uses total
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The spinning-rotor gauge works by measuring how a rotating ball is slowed by the viscosity of the gas being measured. The ball is made of steel and is magnetically levitated inside a steel tube closed at one end and exposed to the gas to be measured at the other. The ball is brought up to speed
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at 59 °F" for measurements taken with mercury or water as the manometric fluid respectively. The word "gauge" or "vacuum" may be added to such a measurement to distinguish between a pressure above or below the atmospheric pressure. Both mm of mercury and inches of water are common pressure
1450:
gauges (such as the mercury column manometer) compare pressure to the hydrostatic force per unit area at the base of a column of fluid. Hydrostatic gauge measurements are independent of the type of gas being measured, and can be designed to have a very linear calibration. They have poor dynamic
1200:
Pressure sensors can vary drastically in technology, design, performance, application suitability and cost. A conservative estimate would be that there may be over 50 technologies and at least 300 companies making pressure sensors worldwide. There is also a category of pressure sensors that are
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is uniform in all directions, so pressure measurements are independent of direction in an immovable (static) fluid. Flow, however, applies additional pressure on surfaces perpendicular to the flow direction, while having little impact on surfaces parallel to the flow direction. This directional
44:
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0.1 mPa is the lowest direct measurement of pressure that is possible with current technology. Other vacuum gauges can measure lower pressures, but only indirectly by measurement of other pressure-dependent properties. These indirect measurements must be calibrated to SI units by a direct
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to measure flow. Differential pressure is measured between two segments of a venturi tube that have a different aperture. The pressure difference between the two segments is directly proportional to the flow rate through the venturi tube. A low pressure sensor is almost always required as the
147:
Everyday pressure measurements, such as for vehicle tire pressure, are usually made relative to ambient air pressure. In other cases measurements are made relative to a vacuum or to some other specific reference. When distinguishing between these zero references, the following terms are used:
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The effective electrical model of the transducer, together with a basic signal conditioning circuit, is shown in the application schematic. The pressure sensor is a fully active
Wheatstone bridge which has been temperature compensated and offset adjusted by means of thick film, laser trimmed
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A pressure sensor may also be used to calculate the level of a fluid. This technique is commonly employed to measure the depth of a submerged body (such as a diver or submarine), or level of contents in a tank (such as in a water tower). For most practical purposes, fluid level is directly
1849:
major manufacturer of gauges. Also in 1849, Bernard
Schaeffer in Magdeburg, Germany patented a successful diaphragm (see below) pressure gauge, which, together with the Bourdon gauge, revolutionized pressure measurement in industry. But in 1875 after Bourdon's patents expired, his company
873:(psi) is still in widespread use in the US and Canada, for measuring, for instance, tire pressure. A letter is often appended to the psi unit to indicate the measurement's zero reference; psia for absolute, psig for gauge, psid for differential, although this practice is discouraged by the
1269:: Uses a diaphragm and pressure cavity to create a variable capacitor to detect strain due to applied pressure, capacitance decreasing as pressure deforms the diaphragm. Common technologies use metal, ceramic, and silicon diaphragms. Capacitive pressure sensors are being integrated into
1313:
effect in certain materials such as quartz to measure the strain upon the sensing mechanism due to pressure. This technology is commonly employed for the measurement of highly dynamic pressures. As the basic principle is dynamic, no static pressures can be measured with piezoelectric
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While static gauge pressure is of primary importance to determining net loads on pipe walls, dynamic pressure is used to measure flow rates and airspeed. Dynamic pressure can be measured by taking the differential pressure between instruments parallel and perpendicular to the flow.
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A single-limb liquid-column manometer has a larger reservoir instead of one side of the U-tube and has a scale beside the narrower column. The column may be inclined to further amplify the liquid movement. Based on the use and structure, following types of manometers are used
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designed to measure in a dynamic mode for capturing very high speed changes in pressure. Example applications for this type of sensor would be in the measuring of combustion pressure in an engine cylinder or in a gas turbine. These sensors are commonly manufactured out of
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electrode known as the collector. The current in the collector is proportional to the rate of ionization, which is a function of the pressure in the system. Hence, measuring the collector current gives the gas pressure. There are several sub-types of ionization gauge.
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In the following illustrations of a compound gauge (vacuum and gauge pressure), the case and window has been removed to show only the dial, pointer and process connection. This particular gauge is a combination vacuum and pressure gauge used for automotive diagnosis:
3177:, up to 36,090 feet (11,000 m). Outside that range, an error will be introduced which can be calculated differently for each different pressure sensor. These error calculations will factor in the error introduced by the change in temperature as we go up.
1775:. The technique is very slow and unsuited to continual monitoring, but is capable of good accuracy. Unlike other manometer gauges, the McLeod gauge reading is dependent on the composition of the gas, since the interpretation relies on the sample compressing as an
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that is applied to the coils is used as the measurement. Due to the extremely stable and repeatable mechanical and thermal properties of quartz and the force balancing which eliminates nearly all physical movement these sensors can be accurate to around 1
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This is useful in aircraft, rockets, satellites, weather balloons, and many other applications. All these applications make use of the relationship between changes in pressure relative to the altitude. This relationship is governed by the following equation:
1646:. When expressed as a pressure head, pressure is specified in units of length and the measurement fluid must be specified. When accuracy is critical, the temperature of the measurement fluid must likewise be specified, because liquid density is a function of
1917:
1097:, for example perform this measurement on airplanes to determine airspeed. The presence of the measuring instrument inevitably acts to divert flow and create turbulence, so its shape is critical to accuracy and the calibration curves are often non-linear.
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A pressure sensor may be used to sense the decay of pressure due to a system leak. This is commonly done by either comparison to a known leak using differential pressure, or by means of utilizing the pressure sensor to measure pressure change over time.
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restriction in the connecting pipe is frequently used to avoid unnecessary wear on the gears and provide an average reading; when the whole gauge is subject to mechanical vibration, the case (including the pointer and dial) can be filled with an oil or
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Electrons emitted from the filament move several times in back-and-forth movements around the grid before finally entering the grid. During these movements, some electrons collide with a gaseous molecule to form a pair of an ion and an electron
1909:
1811:
gauges in modern language. Aneroid gauges are not dependent on the type of gas being measured, unlike thermal and ionization gauges, and are less likely to contaminate the system than hydrostatic gauges. The pressure sensing element may be a
869:(N·m or kg·m·s). This special name for the unit was added in 1971; before that, pressure in SI was expressed in units such as N·m. When indicated, the zero reference is stated in parentheses following the unit, for example 101 kPa (abs). The
2067:
269:, for example, allows the outside air pressure to be exposed to the negative side of the pressure-sensing diaphragm, through a vented cable or a hole on the side of the device, so that it always measures the pressure referred to ambient
2143:/s), and the deceleration rate is measured after switching off the drive, by electromagnetic transducers. The range of the instrument is 5 to 10 Pa (10 Pa with less accuracy). It is accurate and stable enough to be used as a
1880:; vacuum is sensed as a reverse motion. Some aneroid barometers use Bourdon tubes closed at both ends (but most use diaphragms or capsules, see below). When the measured pressure is rapidly pulsing, such as when the gauge is near a
3705:
Lemme, Max C.; Wagner, Stefan; Lee, Kangho; Fan, Xuge; Verbiest, Gerard J.; Wittmann, Sebastian; Lukas, Sebastian; Dolleman, Robin J.; Niklaus, Frank; van der Zant, Herre S. J.; Duesberg, Georg S.; Steeneken, Peter G. (2020-07-20).
1215:
Pressure range, sensitivity, dynamic response and cost all vary by several orders of magnitude from one instrument design to the next. The oldest type is the liquid column (a vertical tube filled with mercury) manometer invented by
163:, so it is equal to gauge pressure plus atmospheric pressure. Absolute pressure sensors are used in applications where a constant reference is required, like for example, high-performance industrial applications such as monitoring
3357:, the water level in the piezometer indicates the pressure in the aquifer, but not necessarily the water table. Piezometer wells can be much smaller in diameter than production wells, and a 5 cm diameter standpipe is common.
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1145:
Front and back of a silicon pressure sensor chip. Note the etched depression in the front; the sensitive area is extremely thin. The back side shows the circuitry, and rectangular contact pads at top and bottom. Size: 4×4
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to detect strain due to an applied pressure, electrical resistance increasing as pressure deforms the material. Common technology types are silicon (monocrystalline), polysilicon thin film, bonded metal foil, thick film,
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In gauges intended to sense small pressures or pressure differences, or require that an absolute pressure be measured, the gear train and needle may be driven by an enclosed and sealed bellows chamber, called an
1064:
without properly identifying the force units). Using the names kilogram, gram, kilogram-force, or gram-force (or their symbols) as a unit of force is prohibited in SI; the unit of force in SI is the newton (N).
1212:, which turn on or off at a particular pressure. For example, a water pump can be controlled by a pressure switch so that it starts when water is released from the system, reducing the pressure in a reservoir.
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1234:
These types of electronic pressure sensors generally use a force collector (such a diaphragm, piston, Bourdon tube, or bellows) to measure strain (or deflection) due to applied force over an area (pressure).
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and relative cost is provided. Information is also provided on pressure-measuring devices that are used in field environments i.e., piston gauges, manometers, and low-absolute-pressure (vacuum) instruments.
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320:
is similar to a gauge pressure sensor except that it measures pressure relative to some fixed pressure rather than the ambient atmospheric pressure (which varies according to the location and the weather).
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is generally glued (foil strain gauge) or deposited (thin-film strain gauge) onto a membrane. Membrane deflection due to pressure causes a resistance change in the strain gauge which can be electronically
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by a current flowing through it and cooled by the gas surrounding it. If the gas pressure is reduced, the cooling effect will decrease, hence the equilibrium temperature of the wire will increase. The
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1893:. Typical high-quality modern gauges provide an accuracy of ±1% of span (Nominal diameter 100mm, Class 1 EN837-1), and a special high-accuracy gauge can be as accurate as 0.1% of full scale.
368:
went further, having his brother-in-law try the experiment at different altitudes on a mountain, and finding indeed that the farther down in the ocean of atmosphere, the higher the pressure.
258:
Using atmospheric pressure as reference is usually signified by a "g" for gauge after the pressure unit, e.g. 70 psig, which means that the pressure measured is the total pressure minus
1779:. Due to the compression process, the McLeod gauge completely ignores partial pressures from non-ideal vapors that condense, such as pump oils, mercury, and even water if compressed enough.
1537:
2311:(RTD) can then be used to measure the temperature of the filament. This temperature is dependent on the rate at which the filament loses heat to the surrounding gas, and therefore on the
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of the material of the tube is magnified by forming the tube into a C shape or even a helix, such that the entire tube tends to straighten out or uncoil elastically as it is pressurized.
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Fluid density and local gravity can vary from one reading to another depending on local factors, so the height of a fluid column does not define pressure precisely. So measurements in "
309:, the manufacturer seals a high vacuum behind the sensing diaphragm. If the process-pressure connection of an absolute-pressure transmitter is open to the air, it will read the actual
280:
A sealed gauge reference is very similar, except that atmospheric pressure is sealed on the negative side of the diaphragm. This is usually adopted on high pressure ranges, such as
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circuit to maximize the output of the sensor and to reduce sensitivity to errors. This is the most commonly employed sensing technology for general purpose pressure measurement.
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1189:
Pressure is an expression of the force required to stop a fluid from expanding, and is usually stated in terms of force per unit area. A pressure sensor usually acts as a
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1807:
used to measure the pressure of a liquid as well as a gas, and they are not the only type of gauge that can operate without fluid. For this reason, they are often called
1710:). Liquid-column pressure gauges have a highly linear calibration. They have poor dynamic response because the fluid in the column may react slowly to a pressure change.
880:
Because pressure was once commonly measured by its ability to displace a column of liquid in a manometer, pressures are often expressed as a depth of a particular fluid (
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media, whereby the resonant frequency is dependent upon the density of the media. Sensors have been made out of vibrating wire, vibrating cylinders, quartz, and silicon
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1972:
Receiver block. This joins the inlet pipe to the fixed end of the Bourdon tube (1) and secures the chassis plate (B). The two holes receive screws that secure the case.
1901:
of full scale. Due to the extremely fine fused quartz structures which must be made by hand these sensors are generally limited to scientific and calibration purposes.
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by not being pointed into the fluid flow. Observation wells give some information on the water level in a formation, but must be read manually. Electrical pressure
1432:
3652:
2184:
silicon pressure sensor chosen for its excellent performance and long-term stability. Integral temperature compensation is provided over a range of 0–50°C using
1416:: Measures the flow of charged gas particles (ions) which varies due to density changes to measure pressure. Common examples are the Hot and Cold Cathode gauges.
295:
on the reverse side of the sensing diaphragm. Then the output signal is offset, so the pressure sensor reads close to zero when measuring atmospheric pressure.
102:(vacuum & pressure). The widely used Bourdon gauge is a mechanical device, which both measures and indicates and is probably the best known type of gauge.
1439:
waves from the bottom of the open ocean. It has a pressure resolution of approximately 1mm of water when measuring pressure at a depth of several kilometers.
5366:
182:
up to 50 bar are manufactured in this way, since otherwise the atmospheric pressure fluctuation (weather) is reflected as an error in the measurement result.
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or a vacuum) is applied to the other. The difference in liquid levels represents the applied pressure. The pressure exerted by a column of fluid of height
329:
For much of human history, the pressure of gases like air was ignored, denied, or taken for granted, but as early as the 6th century BC, Greek philosopher
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1832:
The Bourdon pressure gauge uses the principle that a flattened tube tends to straighten or regain its circular form in cross-section when pressurized. (A
1698:) even under a strong vacuum. For low pressure differences, light oil or water are commonly used (the latter giving rise to units of measurement such as
1694:
the glass, though under exceptionally clean circumstances, the mercury will stick to glass and the barometer may become stuck (the mercury can sustain a
1330:: Techniques include the use of the physical change of an optical fiber to detect strain due to applied pressure. A common example of this type utilizes
3318:
in a system by measuring the height to which a column of the liquid rises against gravity, or a device which measures the pressure (more precisely, the
4265:
3807:
3068:
per unit area. This is useful in weather instrumentation, aircraft, automobiles, and any other machinery that has pressure functionality implemented.
2113:. These devices use the sealed chamber as a reference pressure and are driven by the external pressure. Other sensitive aircraft instruments such as
2965:
of the instantaneous sound pressure over a given interval of time. Sound pressures are normally small and are often expressed in units of microbar.
399:
346:
far end. This validated his belief that air/gas has mass, creating pressure on things around it. Previously, the more popular conclusion, even for
192:
is the difference in pressure between two points. Differential pressure sensors are used to measure many properties, such as pressure drops across
2508:. The filament voltage to ground is usually at a potential of 30 volts, while the grid voltage at 180–210 volts DC, unless there is an optional
4394:
1611:. In other words, the pressure on either end of the liquid (shown in blue in the figure) must be balanced (since the liquid is static), and so
4247:
3791:
3563:
350:, was that air was weightless and it is vacuum that provided force, as in a siphon. The discovery helped bring Torricelli to the conclusion:
1553:
pressure). A very simple version is a U-shaped tube half-full of liquid, one side of which is connected to the region of interest while the
1061:
2519:, with a small ion collector inside the grid. A glass envelope with an opening to the vacuum can surround the electrodes, but usually the
2455:
version is the same, except that electrons are produced in the discharge of a high voltage. Cold cathode gauges are accurate from 10
1106:
2012:
gear, any motion of the Bourdon tube is greatly amplified. A small motion of the tube results in a large motion of the indicator needle.
2650:
shards within the gauge that eventually either short-circuit the electrodes of the gauge or impede the generation of a discharge path.
1365:
with the same precision as a force-balancing measurement, although easier to construct due to the larger size these are no longer used.
1046:
117:
Other methods of pressure measurement involve sensors that can transmit the pressure reading to a remote indicator or control system (
4419:
4387:
4291:
4220:
4085:
3666:
Nagata, Tomio; Terabe, Hiroaki; Kuwahara, Sirou; Sakurai, Shizuki; Tabata, Osamu; Sugiyama, Susumu; Esashi, Masayoshi (1992-08-01).
984:(one atmosphere), which gives one fsw equal to about 0.445 psi. The msw and fsw are the conventional units for measurement of
3872:
Dolleman, Robin J.; Davidovikj, Dejan; Cartamil-Bueno, Santiago J.; van der Zant, Herre S. J.; Steeneken, Peter G. (2016-01-13).
1018:) are most commonly used. Torr and micron usually indicates an absolute pressure, while inHg usually indicates a gauge pressure.
1860:
An original 19th century Eugene Bourdon compound gauge, reading pressure both below and above atmospheric with great sensitivity
2044:). For absolute measurements, welded pressure capsules with diaphragms on either side are often used. Membrane shapes include:
1081:. An instrument facing the flow direction measures the sum of the static and dynamic pressures; this measurement is called the
302:
will never read exactly zero because atmospheric pressure is always changing and the reference in this case is fixed at 1 bar.
4157:
2414:
unstable and dependent on the nature of the gases being measured, which is not always known. They can be calibrated against a
2319:, which uses a single platinum filament as both the heated element and RTD. These gauges are accurate from 10 Torr to 10
4198:
4177:
1389:
1089:. Since dynamic pressure is referenced to static pressure, it is neither gauge nor absolute; it is a differential pressure.
239:
obviating the need for an operator or control system to watch two separate gauges and determine the difference in readings.
5069:
4950:
4492:
4058:
2481:
2447:
2429:
354:
We live submerged at the bottom of an ocean of the element air, which by unquestioned experiments is known to have weight.
3016:
EN 837-3 : Pressure gauges. Diaphragm and capsule pressure gauges. Dimensions, metrology, requirements, and testing.
3588:
3586:
1373:
These types of electronic pressure sensors use other properties (such as density) to infer pressure of a gas, or liquid.
1350:
A force-balanced fused quartz Bourdon tube pressure sensor. The mirror that should be mounted to the armature is absent.
392:
3217:
proportional to pressure. In the case of fresh water where the contents are under atmospheric pressure, 1psi = 27.7 inH
1865:
is usually adjustable. A small-diameter pinion gear is on the pointer shaft, so the motion is magnified further by the
5382:
4009:
3469:
3459:
3365:
or portable readout units, allowing faster or more frequent reading than is possible with open standpipe piezometers.
2550:
1945:
208:
The zero reference in use is usually implied by context, and these words are added only when clarification is needed.
1675:
or venturi), in which case the density ρ should be corrected by subtracting the density of the fluid being measured.
1482:
1021:
Atmospheric pressures are usually stated using hectopascal (hPa), kilopascal (kPa), millibar (mbar) or atmospheres (
4982:
4427:
4023:
3494:
2370:
flowing through it, the resistance (and so the gas pressure) can be determined. This type of gauge was invented by
958:
and a sea-water density of 64 lb/ft. According to the US Navy Diving Manual, one fsw equals 0.30643 msw,
424:
359:
2094:.) This bellows configuration is used in aneroid barometers (barometers with an indicating needle and dial card),
1542:
5285:
4680:
3617:(IMCA D 022 August 2016, Rev. 1 ed.). London, UK: International Marine Contractors' Association. p. 3.
5532:
5361:
5351:
5223:
5213:
5043:
4781:
4579:
4410:
3338:
3228:
3010:
EN 837-1 : Pressure gauges. Bourdon tube pressure gauges. Dimensions, metrology, requirements and testing.
2562:
2556:
2028:
1703:
1346:
306:
4480:
5201:
5176:
5116:
4796:
4737:
4591:
4262:
2953:
pressure deviation from the average pressure caused by a sound wave. Sound pressure can be measured using a
2260:
effect in certain materials such as quartz to measure the strain upon the sensing mechanism due to pressure.
2193:
1850:
1841:
1546:
1082:
929:
385:
4567:
2382:
In two-wire gauges, one wire coil is used as a heater, and the other is used to measure temperature due to
36:
5464:
5275:
5089:
4925:
4900:
4821:
4751:
4730:
4622:
2308:
2121:) have connections both to the internal part of the aneroid chamber and to an external enclosing chamber.
1217:
1194:
976:
902:
896:
870:
842:
434:
342:
4072:
Beckwith, Thomas G.; Marangoni, Roy D. & Lienhard V, John H. (1993). "Measurement of Low Pressures".
1342:: Uses the motion of a wiper along a resistive mechanism to detect the strain caused by applied pressure.
5151:
4960:
4468:
4120:
2359:
2355:
1772:
1479:
The difference in fluid height in a liquid-column manometer is proportional to the pressure difference:
1011:
330:
4374:
2272:
Uses the motion of a wiper along a resistive mechanism to detect the strain caused by applied pressure.
1836:
illustrates this principle.) This change in cross-section may be hardly noticeable, involving moderate
1771:
isolates a sample of gas and compresses it in a modified mercury manometer until the pressure is a few
4615:
2690:
909:" can be converted to SI units as long as attention is paid to the local factors of fluid density and
5504:
5356:
5313:
5206:
5131:
4668:
4514:
4006:
Methods for the Measurement of Fluid Flow in Pipes, Part 1. Orifice Plates, Nozzles and Venturi Tubes
3895:
3719:
3449:
2607:
2509:
2312:
1558:
1401:
989:
419:
266:
259:
217:
106:
3668:"Digital compensated capacitive pressure sensor using CMOS technology for low-pressure measurements"
1856:
5280:
5270:
4811:
4771:
4744:
4519:
4509:
4053:
3504:
3499:
3326:
at a specific point. A piezometer is designed to measure static pressures, and thus differs from a
2580:
2529:
2493:
2421:
2300:
2032:
1785:: from around 10 Torr (roughly 10 Pa) to vacuums as high as 10 Torr (0.1 mPa),
1460:
1331:
1254:
1086:
936:
are still common, as in settings for CPAP machines. Natural gas pipeline pressures are measured in
933:
310:
299:
270:
209:
80:
4555:
114:
vacuum as the zero point reference must be used, giving pressure reading as an absolute pressure.
5231:
4940:
4723:
4642:
3927:
3885:
3430:
3400:
3079:
2279:
2144:
2114:
1990:
Stationary end of Bourdon tube. This communicates with the inlet pipe through the receiver block.
1937:
1881:
1837:
1384:
1221:
997:
913:. Temperature fluctuations change the value of fluid density, while location can affect gravity.
3946:
3013:
EN 837-2 : Pressure gauges. Selection and installation recommendations for pressure gauges.
2985:
Dead-weight tester. This uses known calibrated weights on a piston to generate a known pressure.
2282:
in a sensing mechanism to measure stress, or changes in gas density, caused by applied pressure.
277:
should always read zero pressure when the process pressure connection is held open to the air.
5328:
5074:
4965:
4786:
4287:
4243:
4216:
4194:
4173:
4081:
3919:
3911:
3854:
3787:
3745:
3687:
3559:
3385:
2851:
2461:
2323:, but their calibration is sensitive to the chemical composition of the gases being measured.
2087:
1949:
1898:
1877:
1845:
1798:
1687:
1679:
1464:
1361:
1258:
1022:
985:
943:
889:
3526:
2568:
262:. There are two types of gauge reference pressure: vented gauge (vg) and sealed gauge (sg).
109:, which is set as the zero point, in negative values (for instance, −1 bar or −760
5378:
5265:
5156:
5121:
5096:
4955:
4776:
4100:
3903:
3846:
3815:
3735:
3727:
3679:
3489:
3425:
3390:
3354:
2962:
2367:
2257:
1227:
There are two basic categories of analog pressure sensors: force collector and other types.
1078:
1034:
1026:
993:
955:
910:
213:
131:
5411:
4676:
4529:
3302:
5542:
5494:
5318:
5236:
5171:
5166:
5064:
4930:
4801:
4656:
4575:
4488:
4269:
3405:
2512:
feature, by heating the grid, which may have a high potential of approximately 565 volts.
2497:
2371:
2107:
1713:
When measuring vacuum, the working liquid may evaporate and contaminate the vacuum if its
1664:
1404:
of a gas due to density changes to measure pressure. A common example of this type is the
1209:
1133:
1073:
947:
274:
3976:
3763:
29:
This article is about sensing gas or fluid pressure measurement. Not to be confused with
4476:
3899:
3873:
3723:
1125:
5441:
5333:
5250:
5054:
4816:
4806:
4692:
4587:
4077:
3740:
3707:
3375:
3319:
3192:
2880:
2824:
2627:
2185:
2181:
2171:
1873:
1714:
1683:
1421:
1245:
1110:
1000:
951:
950:(msw) which is defined as equal to one tenth of a bar. The unit used in the US is the
921:
838:
338:
was akin to how gases really do become less dense when warmer, more dense when cooler.
285:
160:
30:
4638:
4563:
4464:
3834:
3667:
3294:
2266:
Uses the physical change of an optical fiber to detect strain due to applied pressure.
291:
There is another way of creating a sealed gauge reference, and this is to seal a high
5526:
5469:
5308:
5186:
5181:
4905:
4826:
4134:
3850:
3819:
3683:
3555:
3334:
of several types can be read automatically, making data acquisition more convenient.
2350:
2041:
1975:
Chassis plate. The dial is attached to this. It contains bearing holes for the axles.
1699:
1672:
1643:
1459:
Piston-type gauges counterbalance the pressure of a fluid with a spring (for example
1310:
1202:
937:
885:
862:
858:
409:
365:
251:
232:
228:
49:
3931:
3578:
3166:{\displaystyle h=(1-(P/P_{\mathrm {ref} })^{0.190284})\times 145366.45\mathrm {ft} }
1959:
1141:
167:, liquid pressure measurement, industrial packaging, industrial process control and
5489:
5484:
5474:
5454:
5141:
5084:
4915:
4632:
3410:
3207:
2599:
2505:
2472:
2452:
2415:
2395:
2346:
2340:
2316:
2304:
2247:
2160:
1941:
1768:
1428:
1424:
1405:
1298:
1274:
1249:
866:
84:
2174:
effect of bonded or formed strain gauges to detect strain due to applied pressure.
1916:
4237:
3907:
3795:
1463:
of comparatively low accuracy) or a solid weight, in which case it is known as a
1060:
Many other hybrid units are used such as mmHg/cm or grams-force/cm (sometimes as
5499:
5196:
5079:
5018:
3464:
3395:
3362:
3350:
3323:
3211:
2545:
2464:
must be used in conjunction with the ionization gauge for accurate measurement.
2243:
2208:
1647:
1634:
In most liquid-column measurements, the result of the measurement is the height
1294:
1117:
1105:
164:
4611:
3353:, especially when the vertical component of flow velocity is significant. In a
1824:
139:
5323:
5303:
5191:
5003:
4998:
4920:
4910:
4791:
4664:
4652:
4536:
4456:
3484:
3474:
3420:
3331:
3327:
2958:
2954:
2572:
2501:
2399:
2383:
2235:
2118:
2110:
2016:
1866:
1833:
1286:
1257:
and sputtered thin film. Generally, the strain gauges are connected to form a
1190:
1094:
1030:
965:
414:
281:
197:
193:
17:
3915:
3858:
3691:
5479:
5459:
5345:
5161:
5146:
4762:
4704:
4688:
4603:
4504:
3731:
3527:"Pressure Sensing 101 – Absolute, Gauge, Differential & Sealed pressure"
3454:
3444:
3380:
3174:
2451:
gauges are accurate from 10 Torr to 10 Torr. The principle behind
2225:
2103:
2099:
2095:
2083:
2071:
1776:
1554:
221:
118:
4599:
4379:
3923:
3749:
2349:
consists of a metal wire open to the pressure being measured. The wire is
1908:
91:. Instruments used to measure and display pressure mechanically are called
4712:
4628:
4551:
3833:
Andrews, M. K.; Turner, G. C.; Harris, P. D.; Harris, I. M. (1993-05-01).
2066:
1885:
1759:
87:. Many techniques have been developed for the measurement of pressure and
5509:
5396:
5126:
5101:
5028:
4945:
4935:
4263:
http://www.wrh.noaa.gov/slc/projects/wxcalc/formulas/pressureAltitude.pdf
3415:
3315:
3061:
2296:
2292:
1890:
1695:
1003:. Both msw and fsw are measured relative to normal atmospheric pressure.
168:
76:
4452:
3033:
PTC 19.2-2010 : The Performance test code for pressure measurement.
2424:
generates electrons, which collide with gas atoms and generate positive
5449:
5421:
5106:
5033:
5023:
5013:
5008:
4716:
3346:
2623:
2590:
2489:
2443:
2299:- its ability to conduct heat increases. In this type of gauge, a wire
1925:
The left side of the face, used for measuring vacuum, is calibrated in
1691:
1690:
is advantageous since this means there will be no pressure errors from
1436:
1159:
347:
334:
255:
goes down. The absolute pressure in the tire is essentially unchanged.
204:
is a device that measures the differential pressure between two inputs.
201:
4700:
4500:
4369:
2331:
5431:
5426:
5416:
5406:
5338:
5136:
5111:
5059:
4869:
4215:(3rd ed.). Van Nostrand Reinhold, New York. pp. 1278–1284.
3479:
2485:
2140:
2091:
2070:
A pile of pressure capsules with corrugated diaphragms in an aneroid
1999:
Link joining pivot pin to lever (5) with pins to allow joint rotation
1054:
292:
88:
68:
4345:
U.S. Navy Diving Manual Revision 7 SS521-AG-PRO-010 0910-LP-115-1921
4135:"Characterization of quartz Bourdon-type high-pressure transducers"
3890:
3808:"Characterization of quartz Bourdon-type high-pressure transducers"
946:
use manometric units: the ambient pressure is measured in units of
833:
105:
A vacuum gauge is used to measure pressures lower than the ambient
4884:
4326:
American Association of State Highway and Transportation Officials
4309:
Soil Mechanics in the design and Construction of the Logan Airport
3977:"Deep-Ocean Bottom Pressure Measurements in the Northeast Pacific"
3293:
3065:
3041:
2980:
2619:
2589:
2492:
is the filament. The three electrodes are a collector or plate, a
2471:
2330:
2207:
2192:
2065:
1958:
1915:
1907:
1855:
1823:
1758:
1577:. Therefore, the pressure difference between the applied pressure
1541:
1474:
1345:
1285:: Measures the displacement of a diaphragm by means of changes in
1140:
1132:
1124:
1116:
1104:
1050:
1042:
888:
calculations. The most common choices for a manometer's fluid are
832:
138:
130:
64:
60:
43:
35:
3612:
2015:
Hair spring to preload the gear train to eliminate gear lash and
1978:
Secondary chassis plate. It supports the outer ends of the axles.
5371:
4879:
4874:
4864:
4859:
4854:
4839:
4541:
3022:
2639:
2631:
2533:
2456:
2363:
2320:
2239:
2234:
Measures the displacement of a diaphragm by means of changes in
2130:
pressure ranges, the spring rate can be increased or decreased.
2037:
1930:
1926:
1719:
1650:. So, for example, pressure head might be written "742.2 mm
1475:
1290:
1270:
1015:
1007:
925:
906:
874:
429:
110:
4383:
3708:"Nanoelectromechanical Sensors Based on Suspended 2D Materials"
2402:, respectively, to measure the temperature of the heated wire.
2618:. The major difference between the two is the position of the
2425:
1663:
heads, which can be converted to S.I. units of pressure using
1155:
1038:
846:
72:
4311:. J. Boston Soc. Civil Eng., Vol 36, No. 2. pp. 192–221.
4284:
Geotechnical Instrumentation for Monitoring Field Performance
1682:
is preferred for its high density (13.534 g/cm) and low
4031:. U.S. Government Printing Office. 1963. pp. A295–A299.
3835:"A resonant pressure sensor based on a squeezed film of gas"
3191:
This is the use of pressure sensors in conjunction with the
2571:
and acceleration voltage and directed at a target to form a
2484:
is composed mainly of three electrodes acting together as a
2418:
which is much more stable and independent of gas chemistry.
1077:
component of pressure in a moving (dynamic) fluid is called
1840:
within the elastic range of easily workable materials. The
884:
inches of water). Manometric measurement is the subject of
854:
125:
Absolute, gauge and differential pressures — zero reference
2224:
Uses a diaphragm and pressure cavity to create a variable
2086:
used a column of liquid such as water or the liquid metal
1876:, relative to ambient atmospheric pressure, as opposed to
3786:
Elastic hologram' pages 113-117, Proc. of the IGC 2010,
2925:
Hot cathode (ionization induced by thermionic emission)
2634:
for operation. Inverted magnetrons can measure down to 1
2295:
increases in density -which may indicate an increase in
1956:
Mechanical details include stationary and moving parts.
1722:(a few 100 Pa) to a few atmospheres (approximately
362:, was essentially the first documented pressure gauge.
159:
is zero-referenced against a perfect vacuum, using an
4211:
Robert M. Besançon, ed. (1990). "Vacuum Techniques".
3636:
3592:
3231:
3091:
2693:
1485:
3361:
are cabled to the surface where they can be read by
3030:
B40.100-2013: Pressure gauges and Gauge attachments.
5440:
5395:
5294:
5258:
5249:
5222:
5042:
4991:
4978:
4893:
4847:
4838:
4761:
4439:
4426:
2575:. In this case a valve lets gas into the grid-cage.
2180:The sensor is generally a temperature compensated,
3249:
3165:
3050:There are many applications for pressure sensors:
2930:Low current measurement; parasitic x-ray emission
2714:
1531:
4351:. Washington, DC.: US Naval Sea Systems Command.
3552:Process control: modeling, design, and simulation
2626:. Neither has a filament, and each may require a
1936:The right portion of the face is used to measure
1467:and may be used for calibration of other gauges.
980:, though elsewhere it states that 33 fsw is
250:Atmospheric pressure is typically about 100
40:Example of the widely used Bourdon pressure gauge
3341:were open wells or standpipes (sometimes called
3225:O. The basic equation for such a measurement is
2998:establish the pressure-measurement uncertainty.
2565:with microchannel plate detector and Faraday cup
1718:gauges can measure pressures ranging from a few
1638:, expressed typically in mm, cm, or inches. The
1162:. Pressure sensors can alternatively be called
1033:. Stress is not a true pressure since it is not
4272:National Oceanic and Atmospheric Administration
3273:= height of fluid column above pressure sensor
3181:levels in buildings for pedestrian navigation.
2654:Comparison of pressure measurement instruments
1993:Moving end of Bourdon tube. This end is sealed.
1981:Posts to join and space the two chassis plates.
1569:is given by the hydrostatic pressure equation,
1532:{\displaystyle h={\frac {P_{a}-P_{o}}{g\rho }}}
1291:linear variable differential transformer (LVDT)
352:
3796:http://www.dspace.cam.ac.uk/handle/1810/225960
2961:in water. The effective sound pressure is the
1591:in a U-tube manometer can be found by solving
1014:(micrometer of mercury), and inch of mercury (
4395:
3947:"The NOAA DART II Description and Disclosure"
3060:This is where the measurement of interest is
2515:The most common ion gauge is the hot-cathode
393:
8:
1273:technology and it is being explored if thin
1137:Miniature digital barometric pressure sensor
52:with a spring and piston tire-pressure gauge
3606:
3604:
2303:is heated by running current through it. A
1789:measurement, most commonly a McLeod gauge.
1431:force collector, is the critical sensor of
924:is measured in millimetres of mercury (see
5255:
4988:
4844:
4436:
4402:
4388:
4380:
4193:, pp. 92–94, John Wiley & Sons, 2005.
3355:confined aquifer under artesian conditions
3314:is either a device used to measure liquid
3007:EN 472 : Pressure gauge - Vocabulary.
2652:
2476:Bayard–Alpert hot-cathode ionization gauge
2002:Lever, an extension of the sector gear (7)
400:
386:
3889:
3739:
3230:
3196:pressure difference is relatively small.
3155:
3140:
3123:
3122:
3113:
3090:
2813:±10% of reading between 10 and 5⋅10 mbar
2692:
2228:to detect strain due to applied pressure.
1512:
1499:
1492:
1484:
1025:). In American and Canadian engineering,
216:are gauge pressures by convention, while
3874:"Graphene Squeeze-Film Pressure Sensors"
3653:"Understanding Vacuum Measurement Units"
3301:
2938:±20% at 10 and 10 mbar ±100% at 10 mbar
2837:±2.5% of reading between 10 and 10 mbar
2428:. The ions are attracted to a suitably
1154:is a device for pressure measurement of
375:
3517:
2500:. The collector current is measured in
2442:Most ion gauges come in two types: hot
2189:please see pressure flow diagram below.
1853:also manufactured Bourdon tube gauges.
143:silicon piezoresistive pressure sensors
2969:frequency response of pressure sensors
2894:±10% of reading between 10 and 1 mbar
2868:±6% of reading between 10 and 10 mbar
2177:Piezoresistive silicon pressure sensor
1049:system, the unit of pressure was the
920:are still encountered in many fields.
4158:Product brochure from Schoonover, Inc
2862:1000 to 10 mbar (const. temperature)
1912:Indicator front with pointer and dial
1220:in 1643. The U-Tube was invented by
7:
3611:Staff (2016). "2 - Diving physics".
3598:, Table 2‑10. Pressure Equivalents..
2460:will usually be unpredictable, so a
2027:A second type of aneroid gauge uses
1041:system the unit of pressure was the
916:Although no longer preferred, these
4286:. Wiley-Interscience. p. 117.
4191:A User's Guide to Vacuum Technology
3298:Above-ground casing of a piezometer
3173:This equation is calibrated for an
3046:Industrial wireless pressure sensor
2839:2.5 to 13.5% between 10 and 1 mbar
2439:: 10 - 10 torr (roughly 10 - 10 Pa)
5538:Underwater diving safety equipment
4358:from the original on Dec 28, 2016.
4322:Manual on Suburface Investigations
3159:
3156:
3130:
3127:
3124:
2694:
1763:A McLeod gauge, drained of mercury
1277:can be used as diaphragm material.
25:
4420:Offshore geotechnical engineering
3839:Sensors and Actuators A: Physical
3672:Sensors and Actuators A: Physical
1920:Mechanical side with Bourdon tube
273:. Thus a vented-gauge reference
59:is the measurement of an applied
4711:
4699:
4687:
4675:
4663:
4651:
4637:
4627:
4610:
4598:
4586:
4574:
4562:
4550:
4528:
4499:
4487:
4475:
4463:
4451:
4172:, pp. 100–102, CRC Press, 1998.
2715:{\displaystyle \Delta P=\rho gh}
1678:Although any fluid can be used,
1045:(ba), equal to 1 dyn·cm. In the
992:and the unit of calibration for
4076:(Fifth ed.). Reading, MA:
3614:Guidance for Diving Supervisors
3525:Taskos, Nikolaos (2020-09-16).
2864:10 to 10 mbar (const. voltage)
2594:Penning vacuum gauge (cut-away)
2201:accuracy of the sensor in use.
2151:Electronic pressure instruments
1750:Inverted differential manometer
4117:Instrumentation Reference Book
3146:
3137:
3107:
3098:
2117:and rate of climb indicators (
1420:A pressure sensor, a resonant
1:
5070:Mechanically stabilized earth
3975:Eble, M. C.; Gonzalez, F. I.
1557:pressure (which might be the
1193:; it generates a signal as a
1006:In vacuum systems, the units
940:, expressed as "inches W.C."
220:, deep vacuum pressures, and
4822:Hydraulic conductivity tests
4057:. 2006-05-04. Archived from
3908:10.1021/acs.nanolett.5b04251
3851:10.1016/0924-4247(93)80196-N
3764:"What is a Pressure Sensor?"
3684:10.1016/0924-4247(92)80189-A
3208:Level sensor § Pressure
2936:±10% between 10 and 10 mbar
2482:hot-cathode ionization gauge
2394:work in this manner using a
5383:Stress distribution in soil
4342:US Navy (1 December 2016).
4213:The Encyclopedia of Physics
4049:"Techniques of High Vacuum"
4010:British Standards Institute
3550:Bequette, B. Wayne (2003).
3470:List of MOSFET applications
3460:Brake fluid pressure sensor
2794:Slower when filter mounted
2551:Microchannel plate detector
2360:function of its temperature
2167:Piezoresistive strain gauge
1584:and the reference pressure
1248:effect of bonded or formed
1241:Piezoresistive strain gauge
1129:Digital air pressure sensor
1069:Static and dynamic pressure
5559:
4533:Pore pressure measurement
4282:Dunnicliff, John (1993) .
4025:Manual of Barometry (WBAN)
3820:10.1088/0026-1394/42/6/S20
3495:Tensiometer (soil science)
3205:
3077:
2598:There are two subtypes of
2578:
2338:
2335:Pirani vacuum gauge (open)
2315:. A common variant is the
1948:on its outer scale and kg/
1796:
1696:negative absolute pressure
1208:Some pressure sensors are
1205:materials such as quartz.
1197:of the pressure imposed.
988:pressure exposure used in
894:
231:where a fluid exists in a
135:Natural gas pressure gauge
28:
5286:Preconsolidation pressure
4681:Standard penetration test
4417:
4104:Canadian Museum of Making
3337:The first piezometers in
3250:{\displaystyle P=\rho gh}
2977:Calibration and standards
2785:Temperature fluctuations
2671:Practical pressure range
2446:and cold cathode. In the
2139:(about 2500 or 3800
1471:Liquid column (manometer)
1010:(millimeter of mercury),
857:unit for pressure is the
381:
298:A sealed gauge reference
79:is typically measured in
4782:California bearing ratio
4580:Rotary-pressure sounding
4411:Geotechnical engineering
4236:Nigel S. Harris (1989).
3339:geotechnical engineering
3265:= density of the fluid,
2915:+100 to -50% of reading
2685:Liquid column manometer
2563:Quadrupole mass analyzer
2557:Quadrupole mass analyzer
2524:are always logarithmic.
2366:across the wire and the
1667:and the above formulas.
928:) in most of the world,
307:absolute pressure sensor
5202:Geosynthetic clay liner
5177:Expanded clay aggregate
4797:Proctor compaction test
4738:Crosshole sonic logging
4724:Nuclear densometer test
4481:Geo-electrical sounding
4170:Basic Vacuum Technology
4074:Mechanical Measurements
3986:. NOAA, U.S. Government
3956:. NOAA, U.S. Government
3306:Symbol used in drawings
3289:Groundwater measurement
3002:European (CEN) Standard
2904:Cold cathode (Penning)
2602:ionization gauges: the
2532:). The number of these
1929:on its outer scale and
1872:Bourdon tubes measures
1851:Schaeffer and Budenberg
1828:Membrane-type manometer
930:central venous pressure
360:Torricelli's experiment
5465:Earthquake engineering
5276:Lateral earth pressure
4901:Hydraulic conductivity
4752:Wave equation analysis
4731:Exploration geophysics
4623:Deformation monitoring
4592:Rotary weight sounding
4307:Casagrande, A (1949).
4239:Modern Vacuum Practice
3343:Casagrande piezometers
3307:
3299:
3251:
3167:
3047:
2986:
2780:Capacitance manometer
2716:
2595:
2477:
2336:
2309:resistance thermometer
2213:
2197:
2074:
1964:
1946:pounds per square inch
1931:centimetres of mercury
1921:
1913:
1861:
1829:
1773:millimetres of mercury
1764:
1747:Differential manometer
1549:
1547:Ring balance manometer
1539:
1533:
1400:: Uses the changes in
1383:: Uses the changes in
1351:
1218:Evangelista Torricelli
1147:
1138:
1130:
1122:
1114:
932:and lung pressures in
903:millimetres of mercury
897:Mercury pressure gauge
850:
356:
343:Evangelista Torricelli
318:sealed pressure sensor
144:
136:
53:
41:
4643:Settlement recordings
4568:Rock control drilling
4469:Cone penetration test
4121:Butterworth-Heinemann
3732:10.34133/2020/8748602
3638:US Navy Diving Manual
3594:US Navy Diving Manual
3345:) installed into an
3305:
3297:
3252:
3206:Further information:
3201:Level / depth sensing
3168:
3078:Further information:
3045:
2984:
2888:Thermal conductivity
2859:Thermal conductivity
2717:
2630:potential of about 4
2593:
2475:
2334:
2212:Application schematic
2211:
2196:
2098:, altitude recording
2069:
2023:Diaphragm (membrane)
1962:
1919:
1911:
1859:
1827:
1762:
1642:is also known as the
1545:
1534:
1478:
1349:
1231:Force collector types
1186:, among other names.
1168:pressure transmitters
1144:
1136:
1128:
1120:
1108:
1029:is often measured in
871:pound per square inch
836:
435:Pound per square inch
341:In the 17th century,
218:atmospheric pressures
188:Differential pressure
142:
134:
83:of force per unit of
47:
39:
5505:Agricultural science
5207:Cellular confinement
4115:Boyes, Walt (2008).
4102:The Engine Indicator
4080:. pp. 591–595.
3450:Atmospheric pressure
3269:= standard gravity,
3229:
3089:
2691:
2622:with respect to the
2608:Frans Michel Penning
2510:electron bombardment
2313:thermal conductivity
2287:Thermal conductivity
2278:Uses the changes in
2134:Spinning-rotor gauge
2115:air speed indicators
2106:instruments used in
2005:Sector gear axle pin
1559:atmospheric pressure
1483:
1461:tire-pressure gauges
1402:thermal conductivity
1332:Fiber Bragg Gratings
1164:pressure transducers
1121:Pressure transmitter
990:decompression tables
934:centimeters of water
420:Technical atmosphere
358:This test, known as
267:pressure transmitter
260:atmospheric pressure
107:atmospheric pressure
57:Pressure measurement
5397:Numerical analysis
5281:Overburden pressure
5271:Pore water pressure
5051:Shoring structures
4926:Reynolds' dilatancy
4827:Water content tests
4812:Triaxial shear test
4772:Soil classification
4745:Pile integrity test
4370:Home Made Manometer
4119:(Fourth ed.).
4054:Tel Aviv University
4012:. 1964. p. 36.
3900:2016NanoL..16..568D
3724:2020Resea202048602L
3642:, Section 18‑2.8.3.
3505:Tire-pressure gauge
3500:Time pressure gauge
2738:Capsule dial gauge
2665:Governing equation
2659:Physical phenomena
2655:
2581:Electron ionization
2530:electron ionization
2517:Bayard–Alpert gauge
2422:Thermionic emission
2388:Thermocouple gauges
2362:: by measuring the
2102:, and the altitude
1996:Pivot and pivot pin
1952:on its inner scale.
1255:silicon-on-sapphire
1176:pressure indicators
1087:stagnation pressure
861:(Pa), equal to one
425:Standard atmosphere
378:
311:barometric pressure
300:pressure transducer
271:barometric pressure
222:altimeter pressures
5372:Slab stabilisation
5352:Stability analysis
4268:2017-07-03 at the
4189:John F. O'Hanlon,
3655:. 9 February 2013.
3431:Vacuum engineering
3308:
3300:
3247:
3221:O / 1Pa = 9.81 mmH
3163:
3080:Pressure altimeter
3048:
2987:
2948:Dynamic transients
2749:±5% of full scale
2712:
2653:
2612:inverted magnetron
2596:
2478:
2337:
2280:resonant frequency
2214:
2198:
2156:Metal strain gauge
2145:secondary standard
2075:
1967:Stationary parts:
1965:
1963:Mechanical details
1944:and is scaled in
1933:on its inner scale
1922:
1914:
1882:reciprocating pump
1862:
1830:
1765:
1700:inches water gauge
1550:
1540:
1529:
1385:resonant frequency
1352:
1222:Christiaan Huygens
1148:
1139:
1131:
1123:
1115:
1095:Pitot-static tubes
1057:per square metre.
998:hyperbaric chamber
851:
376:
247:(gauge pressure).
224:must be absolute.
145:
137:
54:
42:
5520:
5519:
5391:
5390:
5367:Sliding criterion
5329:Response spectrum
5245:
5244:
5075:Pressure grouting
4974:
4973:
4834:
4833:
4787:Direct shear test
4493:Permeability test
4249:978-0-07-707099-1
3814:. November 2005.
3792:978-0-9566139-1-2
3565:978-0-13-353640-9
3386:Deadweight tester
3064:, expressed as a
2945:
2944:
2909:Ionization yield
2852:Wheatstone bridge
2668:Limiting factors
2462:mass spectrometer
2411:Ionization gauges
2392:thermistor gauges
2358:of the wire is a
2327:Pirani (one wire)
2125:Magnetic coupling
1927:inches of mercury
1878:absolute pressure
1799:Aneroid altimeter
1654:" or "4.2 in
1527:
1465:deadweight tester
1259:Wheatstone bridge
1210:pressure switches
994:pneumofathometers
944:Underwater divers
907:inches of mercury
831:
830:
155:Absolute pressure
16:(Redirected from
5550:
5379:Bearing capacity
5266:Effective stress
5256:
5157:Land reclamation
5097:Land development
4992:Natural features
4989:
4956:Specific storage
4845:
4777:Atterberg limits
4715:
4703:
4691:
4679:
4667:
4655:
4641:
4631:
4616:Screw plate test
4614:
4602:
4590:
4578:
4566:
4554:
4532:
4503:
4491:
4479:
4467:
4455:
4437:
4404:
4397:
4390:
4381:
4359:
4357:
4350:
4329:
4319:
4313:
4312:
4304:
4298:
4297:
4279:
4273:
4260:
4254:
4253:
4233:
4227:
4226:
4208:
4202:
4187:
4181:
4166:
4160:
4155:
4149:
4148:
4146:
4145:
4131:
4125:
4124:
4112:
4106:
4098:
4092:
4091:
4069:
4063:
4062:
4045:
4039:
4033:
4032:
4030:
4020:
4014:
4013:
4002:
3996:
3995:
3993:
3991:
3981:
3972:
3966:
3965:
3963:
3961:
3951:
3942:
3936:
3935:
3893:
3869:
3863:
3862:
3830:
3824:
3823:
3804:
3798:
3784:
3778:
3777:
3775:
3774:
3760:
3754:
3753:
3743:
3702:
3696:
3695:
3663:
3657:
3656:
3649:
3643:
3634:
3628:
3625:
3619:
3618:
3608:
3599:
3590:
3581:
3576:
3570:
3569:
3547:
3541:
3540:
3538:
3537:
3522:
3490:Sphygmomanometer
3426:Sphygmomanometer
3391:Dynamic pressure
3320:piezometric head
3256:
3254:
3253:
3248:
3172:
3170:
3169:
3164:
3162:
3145:
3144:
3135:
3134:
3133:
3117:
3073:Altitude sensing
3055:Pressure sensing
2963:root mean square
2823:Spinning rotor (
2721:
2719:
2718:
2713:
2656:
2637:
2614:, also called a
2559:with Faraday cup
2553:with Faraday cup
2406:Ionization gauge
2291:Generally, as a
1741:Simple manometer
1732:
1730:
1727:
1630:
1610:
1538:
1536:
1535:
1530:
1528:
1526:
1518:
1517:
1516:
1504:
1503:
1493:
1172:pressure senders
1079:dynamic pressure
983:
979:
974:
968:
963:
956:standard gravity
954:(fsw), based on
948:metres sea water
918:manometric units
845:(red scale) and
824:
823:
820:
813:
812:
809:
802:
801:
798:
791:
790:
787:
780:
779:
776:
772:
760:
759:
756:
746:
745:
742:
736:
734:
733:
730:
727:
719:
718:
715:
708:
707:
704:
697:
696:
693:
681:
680:
677:
674:
661:
656:
655:
647:
646:
633:
632:
629:
626:
619:
618:
611:
610:
607:
604:
594:
593:
586:
584:
572:
571:
568:
565:
557:
551:
550:
542:
533:
522:
521:
518:
515:
512:
503:
501:
492:
490:
481:
479:
470:
402:
395:
388:
379:
190:
189:
179:
178:
157:
156:
93:pressure gauges,
75:) on a surface.
21:
5558:
5557:
5553:
5552:
5551:
5549:
5548:
5547:
5533:Pressure gauges
5523:
5522:
5521:
5516:
5495:Earth materials
5436:
5398:
5387:
5296:
5290:
5241:
5218:
5172:Earth structure
5167:Erosion control
5065:Ground freezing
5055:Retaining walls
5038:
4980:
4970:
4931:Angle of repose
4889:
4830:
4764:
4757:
4756:
4717:Visible bedrock
4669:Simple sounding
4657:Shear vane test
4433:instrumentation
4432:
4430:
4422:
4413:
4408:
4366:
4355:
4348:
4341:
4338:
4333:
4332:
4320:
4316:
4306:
4305:
4301:
4294:
4281:
4280:
4276:
4270:Wayback Machine
4261:
4257:
4250:
4242:. McGraw-Hill.
4235:
4234:
4230:
4223:
4210:
4209:
4205:
4188:
4184:
4167:
4163:
4156:
4152:
4143:
4141:
4133:
4132:
4128:
4123:. p. 1312.
4114:
4113:
4109:
4099:
4095:
4088:
4071:
4070:
4066:
4047:
4046:
4042:
4036:
4028:
4022:
4021:
4017:
4004:
4003:
3999:
3989:
3987:
3979:
3974:
3973:
3969:
3959:
3957:
3949:
3945:Milburn, Hugh.
3944:
3943:
3939:
3871:
3870:
3866:
3832:
3831:
3827:
3806:
3805:
3801:
3785:
3781:
3772:
3770:
3762:
3761:
3757:
3704:
3703:
3699:
3665:
3664:
3660:
3651:
3650:
3646:
3635:
3631:
3626:
3622:
3610:
3609:
3602:
3591:
3584:
3577:
3573:
3566:
3558:. p. 735.
3549:
3548:
3544:
3535:
3533:
3524:
3523:
3519:
3514:
3509:
3440:
3435:
3406:List of sensors
3371:
3227:
3226:
3224:
3220:
3214:
3136:
3118:
3087:
3086:
3082:
3040:
3027:
3004:
2979:
2950:
2791:±1% of reading
2788:atm to 10 mbar
2767:1000 to 1 mbar
2746:1000 to 1 mbar
2726:atm. to 1 mbar
2689:
2688:
2674:Ideal accuracy
2635:
2588:
2583:
2470:
2440:
2408:
2380:
2372:Marcello Pirani
2343:
2329:
2289:
2153:
2136:
2127:
2108:weather balloon
2090:suspended by a
2064:
2025:
1984:
1822:
1801:
1795:
1786:
1757:
1728:
1725:
1723:
1707:
1684:vapour pressure
1665:unit conversion
1661:
1659:
1653:
1625:
1617:
1612:
1605:
1597:
1592:
1590:
1582:
1519:
1508:
1495:
1494:
1481:
1480:
1473:
1457:
1445:
1435:. DART detects
1357:Force balancing
1282:Electromagnetic
1152:pressure sensor
1103:
1074:Static pressure
1071:
1001:pressure gauges
981:
972:
970:
961:
959:
938:inches of water
899:
821:
818:
816:
810:
807:
805:
799:
796:
794:
788:
785:
783:
777:
774:
770:
768:
757:
754:
752:
743:
740:
738:
731:
728:
725:
724:
722:
716:
713:
711:
705:
702:
700:
694:
691:
689:
678:
675:
672:
670:
659:
653:
651:
644:
642:
630:
627:
624:
622:
616:
614:
608:
605:
602:
600:
591:
589:
582:
580:
569:
566:
563:
561:
555:
548:
546:
540:
531:
519:
516:
513:
510:
508:
499:
497:
488:
486:
477:
475:
468:
406:
377:Pressure units
374:
327:
275:pressure sensor
265:A vented-gauge
244:vacuum pressure
187:
186:
176:
175:
154:
153:
127:
100:compound gauges
34:
23:
22:
15:
12:
11:
5:
5556:
5554:
5546:
5545:
5540:
5535:
5525:
5524:
5518:
5517:
5515:
5514:
5513:
5512:
5502:
5497:
5492:
5487:
5482:
5477:
5472:
5467:
5462:
5457:
5452:
5446:
5444:
5442:Related fields
5438:
5437:
5435:
5434:
5429:
5424:
5419:
5414:
5409:
5403:
5401:
5393:
5392:
5389:
5388:
5386:
5385:
5376:
5375:
5374:
5369:
5364:
5362:Classification
5359:
5354:
5343:
5342:
5341:
5336:
5334:Seismic hazard
5331:
5321:
5316:
5311:
5306:
5300:
5298:
5292:
5291:
5289:
5288:
5283:
5278:
5273:
5268:
5262:
5260:
5253:
5247:
5246:
5243:
5242:
5240:
5239:
5234:
5228:
5226:
5220:
5219:
5217:
5216:
5211:
5210:
5209:
5204:
5199:
5194:
5184:
5179:
5174:
5169:
5164:
5159:
5154:
5149:
5144:
5139:
5134:
5129:
5124:
5119:
5114:
5109:
5104:
5099:
5094:
5093:
5092:
5087:
5082:
5077:
5072:
5067:
5062:
5057:
5048:
5046:
5040:
5039:
5037:
5036:
5031:
5026:
5021:
5016:
5011:
5006:
5001:
4995:
4993:
4986:
4976:
4975:
4972:
4971:
4969:
4968:
4963:
4961:Shear strength
4958:
4953:
4948:
4943:
4938:
4936:Friction angle
4933:
4928:
4923:
4918:
4913:
4908:
4903:
4897:
4895:
4891:
4890:
4888:
4887:
4882:
4877:
4872:
4867:
4862:
4857:
4851:
4849:
4842:
4836:
4835:
4832:
4831:
4829:
4824:
4819:
4817:Oedometer test
4814:
4809:
4807:Sieve analysis
4804:
4799:
4794:
4789:
4784:
4779:
4774:
4769:
4767:
4759:
4758:
4755:
4754:
4748:
4747:
4741:
4740:
4734:
4733:
4727:
4726:
4720:
4719:
4708:
4707:
4696:
4695:
4693:Total sounding
4684:
4683:
4672:
4671:
4660:
4659:
4648:
4647:
4646:
4645:
4635:
4619:
4618:
4607:
4606:
4595:
4594:
4583:
4582:
4571:
4570:
4559:
4558:
4547:
4546:
4545:
4544:
4539:
4525:
4524:
4523:
4522:
4517:
4512:
4496:
4495:
4484:
4483:
4472:
4471:
4460:
4459:
4448:
4447:
4445:
4434:
4424:
4423:
4418:
4415:
4414:
4409:
4407:
4406:
4399:
4392:
4384:
4378:
4377:
4372:
4365:
4364:External links
4362:
4361:
4360:
4337:
4334:
4331:
4330:
4314:
4299:
4292:
4274:
4255:
4248:
4228:
4221:
4203:
4182:
4161:
4150:
4126:
4107:
4093:
4086:
4078:Addison-Wesley
4064:
4061:on 2006-05-04.
4040:
4034:
4015:
3997:
3967:
3937:
3884:(1): 568–571.
3864:
3845:(3): 219–226.
3825:
3799:
3779:
3755:
3697:
3678:(2): 173–177.
3658:
3644:
3629:
3620:
3600:
3582:
3571:
3564:
3542:
3516:
3515:
3513:
3510:
3508:
3507:
3502:
3497:
3492:
3487:
3482:
3477:
3472:
3467:
3462:
3457:
3452:
3447:
3441:
3439:
3436:
3434:
3433:
3428:
3423:
3418:
3413:
3408:
3403:
3398:
3393:
3388:
3383:
3378:
3376:Air core gauge
3372:
3370:
3367:
3292:
3291:
3281:
3280:
3246:
3243:
3240:
3237:
3234:
3222:
3218:
3204:
3203:
3193:venturi effect
3189:
3188:
3161:
3158:
3154:
3151:
3148:
3143:
3139:
3132:
3129:
3126:
3121:
3116:
3112:
3109:
3106:
3103:
3100:
3097:
3094:
3076:
3075:
3058:
3057:
3039:
3036:
3035:
3034:
3031:
3026:
3019:
3018:
3017:
3014:
3011:
3008:
3003:
3000:
2978:
2975:
2974:
2973:
2970:
2949:
2946:
2943:
2942:
2940:
2934:
2933:10 to 10 mbar
2931:
2928:
2926:
2923:
2919:
2918:
2916:
2913:
2912:10 to 10 mbar
2910:
2907:
2905:
2902:
2898:
2897:
2895:
2892:
2889:
2886:
2884:
2881:Seebeck effect
2879:Thermocouple (
2877:
2873:
2872:
2869:
2866:
2860:
2857:
2855:
2848:
2844:
2843:
2841:
2835:
2834:10 to 10 mbar
2832:
2830:
2828:
2821:
2817:
2816:
2814:
2811:
2810:10 to 10 mbar
2808:
2806:
2803:
2800:
2796:
2795:
2792:
2789:
2786:
2783:
2781:
2778:
2774:
2773:
2770:
2768:
2765:
2763:
2761:
2758:
2754:
2753:
2750:
2747:
2744:
2741:
2739:
2736:
2732:
2731:
2729:
2727:
2724:
2722:
2711:
2708:
2705:
2702:
2699:
2696:
2686:
2683:
2679:
2678:
2677:Response time
2675:
2672:
2669:
2666:
2663:
2660:
2587:
2584:
2577:
2576:
2566:
2560:
2554:
2548:
2488:, wherein the
2469:
2466:
2435:
2407:
2404:
2379:
2376:
2339:Main article:
2328:
2325:
2288:
2285:
2284:
2283:
2276:
2273:
2270:
2269:Potentiometric
2267:
2264:
2261:
2254:
2251:
2238:(reluctance),
2232:
2229:
2222:
2191:
2190:
2182:piezoresistive
2178:
2175:
2172:piezoresistive
2168:
2165:
2157:
2152:
2149:
2135:
2132:
2126:
2123:
2063:
2060:
2059:
2058:
2055:
2054:Flattened tube
2052:
2049:
2031:of a flexible
2024:
2021:
2020:
2019:
2013:
2009:
2006:
2003:
2000:
1997:
1994:
1991:
1986:Moving parts:
1983:
1982:
1979:
1976:
1973:
1969:
1954:
1953:
1934:
1874:gauge pressure
1846:Eugène Bourdon
1821:
1818:
1794:
1791:
1781:
1756:
1753:
1752:
1751:
1748:
1745:
1744:Micromanometer
1742:
1715:vapor pressure
1705:
1657:
1655:
1651:
1623:
1615:
1603:
1595:
1588:
1580:
1525:
1522:
1515:
1511:
1507:
1502:
1498:
1491:
1488:
1472:
1469:
1456:
1453:
1444:
1441:
1422:quartz crystal
1418:
1417:
1409:
1393:
1375:
1374:
1371:
1367:
1366:
1344:
1343:
1339:Potentiometric
1335:
1323:
1315:
1302:
1289:(reluctance),
1278:
1262:
1246:piezoresistive
1236:
1235:
1232:
1111:pressure gauge
1102:
1099:
1083:total pressure
1070:
1067:
952:foot sea water
922:Blood pressure
839:pressure gauge
829:
828:
825:
814:
803:
792:
781:
766:
765:1 lbf/in
762:
761:
750:
747:
720:
709:
698:
687:
683:
682:
668:
665:
662:
657:
648:
639:
635:
634:
620:
612:
598:
595:
587:
578:
574:
573:
558:
552:
543:
537:
534:
529:
525:
524:
505:
494:
483:
472:
465:
462:
458:
457:
454:
451:
448:
445:
442:
438:
437:
432:
427:
422:
417:
412:
407:
405:
404:
397:
390:
382:
373:
370:
326:
323:
305:To produce an
229:working fluids
214:blood pressure
206:
205:
183:
177:Gauge pressure
172:
161:absolute scale
126:
123:
31:Tactile sensor
24:
18:Micromanometer
14:
13:
10:
9:
6:
4:
3:
2:
5555:
5544:
5541:
5539:
5536:
5534:
5531:
5530:
5528:
5511:
5508:
5507:
5506:
5503:
5501:
5498:
5496:
5493:
5491:
5488:
5486:
5483:
5481:
5478:
5476:
5473:
5471:
5470:Geomorphology
5468:
5466:
5463:
5461:
5458:
5456:
5453:
5451:
5448:
5447:
5445:
5443:
5439:
5433:
5430:
5428:
5425:
5423:
5420:
5418:
5415:
5413:
5410:
5408:
5405:
5404:
5402:
5400:
5394:
5384:
5380:
5377:
5373:
5370:
5368:
5365:
5363:
5360:
5358:
5355:
5353:
5350:
5349:
5347:
5344:
5340:
5337:
5335:
5332:
5330:
5327:
5326:
5325:
5322:
5320:
5317:
5315:
5314:Consolidation
5312:
5310:
5309:Frost heaving
5307:
5305:
5302:
5301:
5299:
5293:
5287:
5284:
5282:
5279:
5277:
5274:
5272:
5269:
5267:
5264:
5263:
5261:
5257:
5254:
5252:
5248:
5238:
5235:
5233:
5230:
5229:
5227:
5225:
5221:
5215:
5212:
5208:
5205:
5203:
5200:
5198:
5195:
5193:
5190:
5189:
5188:
5187:Geosynthetics
5185:
5183:
5182:Crushed stone
5180:
5178:
5175:
5173:
5170:
5168:
5165:
5163:
5160:
5158:
5155:
5153:
5150:
5148:
5145:
5143:
5140:
5138:
5137:Cut-and-cover
5135:
5133:
5130:
5128:
5125:
5123:
5120:
5118:
5115:
5113:
5110:
5108:
5105:
5103:
5100:
5098:
5095:
5091:
5088:
5086:
5083:
5081:
5078:
5076:
5073:
5071:
5068:
5066:
5063:
5061:
5058:
5056:
5053:
5052:
5050:
5049:
5047:
5045:
5041:
5035:
5032:
5030:
5027:
5025:
5022:
5020:
5017:
5015:
5012:
5010:
5007:
5005:
5002:
5000:
4997:
4996:
4994:
4990:
4987:
4984:
4977:
4967:
4964:
4962:
4959:
4957:
4954:
4952:
4949:
4947:
4944:
4942:
4939:
4937:
4934:
4932:
4929:
4927:
4924:
4922:
4919:
4917:
4914:
4912:
4909:
4907:
4906:Water content
4904:
4902:
4899:
4898:
4896:
4892:
4886:
4883:
4881:
4878:
4876:
4873:
4871:
4868:
4866:
4863:
4861:
4858:
4856:
4853:
4852:
4850:
4846:
4843:
4841:
4837:
4828:
4825:
4823:
4820:
4818:
4815:
4813:
4810:
4808:
4805:
4803:
4800:
4798:
4795:
4793:
4790:
4788:
4785:
4783:
4780:
4778:
4775:
4773:
4770:
4768:
4766:
4760:
4753:
4750:
4749:
4746:
4743:
4742:
4739:
4736:
4735:
4732:
4729:
4728:
4725:
4722:
4721:
4718:
4714:
4710:
4709:
4706:
4702:
4698:
4697:
4694:
4690:
4686:
4685:
4682:
4678:
4674:
4673:
4670:
4666:
4662:
4661:
4658:
4654:
4650:
4649:
4644:
4640:
4636:
4634:
4630:
4626:
4625:
4624:
4621:
4620:
4617:
4613:
4609:
4608:
4605:
4604:Sample series
4601:
4597:
4596:
4593:
4589:
4585:
4584:
4581:
4577:
4573:
4572:
4569:
4565:
4561:
4560:
4557:
4553:
4549:
4548:
4543:
4540:
4538:
4535:
4534:
4531:
4527:
4526:
4521:
4518:
4516:
4513:
4511:
4508:
4507:
4506:
4502:
4498:
4497:
4494:
4490:
4486:
4485:
4482:
4478:
4474:
4473:
4470:
4466:
4462:
4461:
4458:
4454:
4450:
4449:
4446:
4443:
4438:
4435:
4429:
4428:Investigation
4425:
4421:
4416:
4412:
4405:
4400:
4398:
4393:
4391:
4386:
4385:
4382:
4376:
4373:
4371:
4368:
4367:
4363:
4354:
4347:
4346:
4340:
4339:
4335:
4327:
4323:
4318:
4315:
4310:
4303:
4300:
4295:
4293:0-471-00546-0
4289:
4285:
4278:
4275:
4271:
4267:
4264:
4259:
4256:
4251:
4245:
4241:
4240:
4232:
4229:
4224:
4222:0-442-00522-9
4218:
4214:
4207:
4204:
4200:
4196:
4192:
4186:
4183:
4179:
4175:
4171:
4168:A. Chambers,
4165:
4162:
4159:
4154:
4151:
4140:
4136:
4130:
4127:
4122:
4118:
4111:
4108:
4105:
4103:
4097:
4094:
4089:
4087:0-201-56947-7
4083:
4079:
4075:
4068:
4065:
4060:
4056:
4055:
4050:
4044:
4041:
4038:
4035:
4027:
4026:
4019:
4016:
4011:
4007:
4001:
3998:
3985:
3978:
3971:
3968:
3955:
3948:
3941:
3938:
3933:
3929:
3925:
3921:
3917:
3913:
3909:
3905:
3901:
3897:
3892:
3887:
3883:
3879:
3875:
3868:
3865:
3860:
3856:
3852:
3848:
3844:
3840:
3836:
3829:
3826:
3821:
3817:
3813:
3809:
3803:
3800:
3797:
3793:
3789:
3783:
3780:
3769:
3765:
3759:
3756:
3751:
3747:
3742:
3737:
3733:
3729:
3725:
3721:
3717:
3713:
3709:
3701:
3698:
3693:
3689:
3685:
3681:
3677:
3673:
3669:
3662:
3659:
3654:
3648:
3645:
3641:
3639:
3633:
3630:
3624:
3621:
3616:
3615:
3607:
3605:
3601:
3597:
3595:
3589:
3587:
3583:
3580:
3575:
3572:
3567:
3561:
3557:
3556:Prentice Hall
3553:
3546:
3543:
3532:
3528:
3521:
3518:
3511:
3506:
3503:
3501:
3498:
3496:
3493:
3491:
3488:
3486:
3483:
3481:
3478:
3476:
3473:
3471:
3468:
3466:
3463:
3461:
3458:
3456:
3453:
3451:
3448:
3446:
3443:
3442:
3437:
3432:
3429:
3427:
3424:
3422:
3419:
3417:
3414:
3412:
3409:
3407:
3404:
3402:
3399:
3397:
3394:
3392:
3389:
3387:
3384:
3382:
3379:
3377:
3374:
3373:
3368:
3366:
3364:
3358:
3356:
3352:
3348:
3344:
3340:
3335:
3333:
3329:
3325:
3321:
3317:
3313:
3304:
3296:
3290:
3287:
3286:
3285:
3279:
3276:
3275:
3274:
3272:
3268:
3264:
3260:
3244:
3241:
3238:
3235:
3232:
3213:
3209:
3202:
3199:
3198:
3197:
3194:
3187:
3184:
3183:
3182:
3178:
3176:
3152:
3149:
3141:
3119:
3114:
3110:
3104:
3101:
3095:
3092:
3081:
3074:
3071:
3070:
3069:
3067:
3063:
3056:
3053:
3052:
3051:
3044:
3037:
3032:
3029:
3028:
3024:
3020:
3015:
3012:
3009:
3006:
3005:
3001:
2999:
2995:
2991:
2983:
2976:
2971:
2968:
2967:
2966:
2964:
2960:
2957:in air and a
2956:
2947:
2941:
2939:
2935:
2932:
2929:
2927:
2924:
2921:
2920:
2917:
2914:
2911:
2908:
2906:
2903:
2900:
2899:
2896:
2893:
2891:5 to 10 mbar
2890:
2887:
2885:
2882:
2878:
2875:
2874:
2870:
2867:
2865:
2861:
2858:
2856:
2853:
2849:
2846:
2845:
2842:
2840:
2836:
2833:
2831:
2829:
2826:
2822:
2819:
2818:
2815:
2812:
2809:
2807:
2804:
2801:
2798:
2797:
2793:
2790:
2787:
2784:
2782:
2779:
2776:
2775:
2771:
2769:
2766:
2764:
2762:
2760:Strain gauge
2759:
2756:
2755:
2751:
2748:
2745:
2742:
2740:
2737:
2734:
2733:
2730:
2728:
2725:
2723:
2709:
2706:
2703:
2700:
2697:
2687:
2684:
2681:
2680:
2676:
2673:
2670:
2667:
2664:
2661:
2658:
2657:
2651:
2647:
2643:
2641:
2633:
2629:
2625:
2621:
2617:
2616:Redhead gauge
2613:
2609:
2606:(invented by
2605:
2604:Penning gauge
2601:
2592:
2585:
2582:
2574:
2570:
2567:
2564:
2561:
2558:
2555:
2552:
2549:
2547:
2544:
2543:
2542:
2538:
2535:
2531:
2525:
2522:
2518:
2513:
2511:
2507:
2503:
2499:
2495:
2491:
2487:
2483:
2474:
2467:
2465:
2463:
2458:
2454:
2449:
2445:
2438:
2434:
2431:
2427:
2423:
2419:
2417:
2412:
2405:
2403:
2401:
2397:
2393:
2389:
2385:
2377:
2375:
2373:
2369:
2365:
2361:
2357:
2352:
2348:
2342:
2333:
2326:
2324:
2322:
2318:
2314:
2310:
2306:
2302:
2298:
2294:
2286:
2281:
2277:
2274:
2271:
2268:
2265:
2262:
2259:
2258:piezoelectric
2255:
2253:Piezoelectric
2252:
2249:
2245:
2241:
2237:
2233:
2230:
2227:
2223:
2220:
2219:
2218:
2210:
2206:
2202:
2195:
2187:
2186:laser-trimmed
2183:
2179:
2176:
2173:
2169:
2166:
2162:
2158:
2155:
2154:
2150:
2148:
2146:
2142:
2133:
2131:
2124:
2122:
2120:
2116:
2112:
2109:
2105:
2101:
2097:
2093:
2089:
2085:
2081:
2073:
2068:
2061:
2056:
2053:
2050:
2047:
2046:
2045:
2043:
2039:
2034:
2030:
2022:
2018:
2014:
2010:
2007:
2004:
2001:
1998:
1995:
1992:
1989:
1988:
1987:
1980:
1977:
1974:
1971:
1970:
1968:
1961:
1957:
1951:
1947:
1943:
1939:
1935:
1932:
1928:
1924:
1923:
1918:
1910:
1906:
1902:
1900:
1894:
1892:
1887:
1883:
1879:
1875:
1870:
1868:
1858:
1854:
1852:
1847:
1843:
1839:
1835:
1826:
1819:
1817:
1815:
1810:
1805:
1800:
1792:
1790:
1784:
1780:
1778:
1774:
1770:
1761:
1754:
1749:
1746:
1743:
1740:
1739:
1738:
1734:
1721:
1716:
1711:
1709:
1704:millimetres H
1701:
1697:
1693:
1689:
1686:. Its convex
1685:
1681:
1676:
1674:
1673:orifice plate
1668:
1666:
1649:
1645:
1644:pressure head
1641:
1637:
1632:
1629:
1622:
1618:
1609:
1602:
1598:
1587:
1583:
1576:
1572:
1568:
1564:
1560:
1556:
1548:
1544:
1523:
1520:
1513:
1509:
1505:
1500:
1496:
1489:
1486:
1477:
1470:
1468:
1466:
1462:
1454:
1452:
1449:
1442:
1440:
1438:
1434:
1430:
1426:
1423:
1415:
1414:
1410:
1407:
1403:
1399:
1398:
1394:
1391:
1386:
1382:
1381:
1377:
1376:
1372:
1369:
1368:
1363:
1359:
1358:
1354:
1353:
1348:
1341:
1340:
1336:
1333:
1329:
1328:
1324:
1321:
1320:
1316:
1312:
1311:piezoelectric
1308:
1307:
1306:Piezoelectric
1303:
1300:
1296:
1292:
1288:
1284:
1283:
1279:
1276:
1272:
1268:
1267:
1263:
1260:
1256:
1251:
1250:strain gauges
1247:
1243:
1242:
1238:
1237:
1233:
1230:
1229:
1228:
1225:
1223:
1219:
1213:
1211:
1206:
1204:
1203:piezoelectric
1198:
1196:
1192:
1187:
1185:
1181:
1177:
1173:
1169:
1165:
1161:
1157:
1153:
1143:
1135:
1127:
1119:
1112:
1107:
1100:
1098:
1096:
1090:
1088:
1084:
1080:
1075:
1068:
1066:
1063:
1058:
1056:
1053:, equal to 1
1052:
1048:
1044:
1040:
1036:
1032:
1028:
1024:
1019:
1017:
1013:
1009:
1004:
1002:
999:
995:
991:
987:
982:14.7 psi
978:
967:
957:
953:
949:
945:
941:
939:
935:
931:
927:
923:
919:
914:
912:
908:
904:
898:
893:
891:
887:
886:pressure head
883:
878:
876:
872:
868:
864:
860:
856:
849:(black scale)
848:
844:
840:
835:
826:
815:
804:
793:
782:
767:
764:
763:
751:
748:
721:
710:
699:
688:
685:
684:
669:
666:
663:
658:
649:
640:
637:
636:
621:
613:
599:
596:
588:
579:
576:
575:
559:
553:
544:
538:
535:
530:
527:
526:
506:
495:
484:
473:
466:
463:
460:
459:
455:
452:
449:
446:
443:
440:
439:
436:
433:
431:
428:
426:
423:
421:
418:
416:
413:
411:
408:
403:
398:
396:
391:
389:
384:
383:
380:
371:
369:
367:
366:Blaise Pascal
363:
361:
355:
351:
349:
344:
339:
336:
332:
324:
322:
319:
314:
312:
308:
303:
301:
296:
294:
289:
288:is exceeded.
287:
283:
278:
276:
272:
268:
263:
261:
256:
253:
248:
245:
240:
236:
234:
233:closed system
230:
225:
223:
219:
215:
211:
210:Tire pressure
203:
199:
195:
191:
184:
180:
173:
170:
166:
162:
158:
151:
150:
149:
141:
133:
129:
124:
122:
120:
115:
112:
108:
103:
101:
97:
96:vacuum gauges
94:
90:
86:
82:
78:
74:
70:
66:
62:
58:
51:
50:tire pressure
46:
38:
32:
27:
19:
5490:Biogeography
5485:Hydrogeology
5475:Soil science
5455:Geochemistry
5214:Infiltration
5142:Cut and fill
5085:Soil nailing
4951:Permeability
4916:Bulk density
4633:Inclinometer
4556:Ram sounding
4441:
4344:
4321:
4317:
4308:
4302:
4283:
4277:
4258:
4238:
4231:
4212:
4206:
4190:
4185:
4169:
4164:
4153:
4142:. Retrieved
4139:ResearchGate
4138:
4129:
4116:
4110:
4101:
4096:
4073:
4067:
4059:the original
4052:
4043:
4037:
4024:
4018:
4005:
4000:
3988:. Retrieved
3983:
3970:
3958:. Retrieved
3953:
3940:
3881:
3878:Nano Letters
3877:
3867:
3842:
3838:
3828:
3811:
3802:
3782:
3771:. Retrieved
3767:
3758:
3715:
3711:
3700:
3675:
3671:
3661:
3647:
3637:
3632:
3623:
3613:
3593:
3574:
3551:
3545:
3534:. Retrieved
3530:
3520:
3438:Applications
3411:Isoteniscope
3363:data loggers
3359:
3342:
3336:
3311:
3309:
3288:
3282:
3278:Leak testing
3277:
3270:
3266:
3262:
3261:= pressure,
3258:
3215:
3200:
3190:
3186:Flow sensing
3185:
3179:
3083:
3072:
3059:
3054:
3049:
3038:Applications
2996:
2992:
2988:
2951:
2937:
2863:
2838:
2805:Boyle's law
2648:
2644:
2615:
2611:
2603:
2600:cold-cathode
2597:
2586:Cold cathode
2539:
2526:
2520:
2516:
2514:
2506:electrometer
2479:
2453:cold cathode
2441:
2437:Useful range
2436:
2420:
2416:McLeod gauge
2410:
2409:
2396:thermocouple
2391:
2387:
2381:
2347:Pirani gauge
2344:
2341:Pirani gauge
2317:Pirani gauge
2305:thermocouple
2290:
2248:eddy current
2215:
2203:
2199:
2161:strain gauge
2137:
2128:
2079:
2076:
2026:
1985:
1966:
1955:
1940:pressure or
1903:
1895:
1871:
1863:
1831:
1820:Bourdon tube
1814:Bourdon tube
1813:
1808:
1803:
1802:
1787:
1783:Useful range
1782:
1769:McLeod gauge
1766:
1755:McLeod gauge
1735:
1712:
1677:
1669:
1639:
1635:
1633:
1627:
1620:
1613:
1607:
1600:
1593:
1585:
1578:
1574:
1570:
1566:
1565:and density
1562:
1551:
1458:
1447:
1446:
1429:Bourdon tube
1425:strain gauge
1419:
1412:
1411:
1406:Pirani gauge
1396:
1395:
1379:
1378:
1356:
1355:
1338:
1337:
1326:
1325:
1319:Strain-Gauge
1318:
1317:
1305:
1304:
1299:eddy current
1281:
1280:
1275:2D materials
1265:
1264:
1240:
1239:
1226:
1214:
1207:
1199:
1188:
1183:
1179:
1175:
1171:
1167:
1163:
1151:
1149:
1091:
1072:
1059:
1020:
1005:
942:
917:
915:
900:
881:
879:
867:square metre
852:
686:1 Torr
364:
357:
353:
340:
328:
317:
315:
304:
297:
290:
279:
264:
257:
249:
243:
241:
237:
226:
207:
185:
174:
165:vacuum pumps
152:
146:
128:
116:
104:
99:
95:
92:
85:surface area
56:
55:
26:
5500:Archaeology
5224:Foundations
5197:Geomembrane
5080:Slurry wall
5019:Water table
4983:Interaction
4979:Structures
4966:Sensitivity
4763:Laboratory
3465:Depth gauge
3396:Force gauge
3351:water table
3332:transducers
3324:groundwater
3212:Depth gauge
2922:Ionization
2901:Ionization
2799:Mechanical
2777:Mechanical
2757:Mechanical
2735:Mechanical
2682:Mechanical
2662:Instrument
2610:), and the
2573:sputter gun
2546:Faraday cup
2502:picoamperes
2468:Hot cathode
2448:hot cathode
2244:Hall effect
2119:variometers
2111:radiosondes
2040:(roughly 1
2008:Sector gear
1942:turbo boost
1648:temperature
1448:Hydrostatic
1443:Hydrostatic
1370:Other types
1309:: Uses the
1295:Hall effect
1244:: Uses the
1180:piezometers
1101:Instruments
841:reading in
638:1 atm
528:1 bar
198:air filters
194:oil filters
171:inspection.
5527:Categories
5357:Mitigation
5339:Shear wave
5324:Earthquake
5319:Compaction
5304:Permafrost
5295:Phenomena/
5192:Geotextile
5117:Embankment
5107:Excavation
5044:Earthworks
5004:Vegetation
4999:Topography
4921:Thixotropy
4911:Void ratio
4894:Properties
4792:Hydrometer
4537:Piezometer
4457:Core drill
4199:0471467154
4178:0585254915
4144:2019-05-05
3891:1510.06919
3812:Metrologia
3773:2018-05-09
3627:Page 2-12.
3536:2020-09-16
3531:ES Systems
3512:References
3485:Pitot tube
3475:MAP sensor
3421:Piezometer
3328:pitot tube
3312:piezometer
2959:hydrophone
2955:microphone
2876:Transport
2847:Transport
2820:Transport
2579:See also:
2521:nude gauge
2400:thermistor
2384:convection
2356:resistance
2250:principle.
2236:inductance
2221:Capacitive
2100:barographs
2096:altimeters
2084:barometers
2051:Corrugated
2029:deflection
2017:hysteresis
1867:gear ratio
1834:party horn
1809:mechanical
1797:See also:
1671:across an
1451:response.
1413:Ionization
1301:principle.
1287:inductance
1266:Capacitive
1191:transducer
1184:manometers
895:See also:
577:1 at
461:1 Pa
331:Anaximenes
282:hydraulics
5480:Hydrology
5460:Petrology
5348:analysis
5346:Landslide
5251:Mechanics
5162:Track bed
5147:Fill dirt
5132:Terracing
4705:Trial pit
4520:Statnamic
4505:Load test
4375:Manometer
3916:1530-6984
3859:0924-4247
3692:0924-4247
3455:Barometer
3445:Altimeter
3381:Barometer
3239:ρ
3175:altimeter
3153:145366.45
3150:×
3105:−
3025:Standards
2972:resonance
2743:Friction
2704:ρ
2695:Δ
2638:10
2256:Uses the
2226:capacitor
2170:Uses the
2164:measured.
2104:telemetry
2082:. (Early
2072:barograph
1938:fuel pump
1777:ideal gas
1555:reference
1524:ρ
1506:−
1224:in 1661.
1113:in action
1037:. In the
456:(lbf/in)
286:diaphragm
242:Moderate
227:For most
119:telemetry
48:Checking
5510:Agrology
5399:software
5297:problems
5127:Causeway
5102:Landfill
5029:Subgrade
4946:Porosity
4941:Cohesion
4353:Archived
4328:page 182
4324:, 1988,
4266:Archived
3984:noaa.gov
3954:noaa.gov
3932:23331693
3924:26695136
3750:32766550
3718:: 1–25.
3712:Research
3416:Pressure
3369:See also
3316:pressure
3142:0.190284
3062:pressure
2850:Pirani (
2569:Ion lens
2496:, and a
2494:filament
2378:Two-wire
2301:filament
2297:pressure
2293:real gas
2275:Resonant
2246:, or by
2231:Magnetic
2033:membrane
1891:glycerin
1838:stresses
1731: Pa
1688:meniscus
1380:Resonant
1314:sensors.
1297:, or by
1195:function
169:aviation
77:Pressure
5450:Geology
5422:SVSlope
5232:Shallow
5152:Grading
5090:Tieback
5034:Subsoil
5024:Bedrock
5014:Topsoil
5009:Terrain
4802:R-value
4765:testing
4515:Dynamic
4442:in situ
4440:Field (
4336:Sources
3990:4 April
3960:4 April
3896:Bibcode
3741:7388062
3720:Bibcode
3347:aquifer
2802:McLeod
2624:cathode
2490:cathode
2444:cathode
2368:current
2364:voltage
2263:Optical
2088:mercury
2080:aneroid
2062:Bellows
2057:Capsule
1886:orifice
1804:Aneroid
1793:Aneroid
1692:wetting
1680:mercury
1437:tsunami
1427:with a
1397:Thermal
1327:Optical
1160:liquids
911:gravity
890:mercury
735:
723:
690:133.322
615:735.559
523:lbf/in
507:1 Pa =
496:1 Pa =
485:1 Pa =
474:1 Pa =
467:1 Pa =
453:(Torr)
348:Galileo
335:Miletus
325:History
202:DP cell
5543:Vacuum
5432:Plaxis
5427:UTEXAS
5417:SVFlux
5407:SEEP2D
5259:Forces
5112:Trench
5060:Gabion
4870:Gravel
4510:Static
4290:
4246:
4219:
4197:
4176:
4084:
3930:
3922:
3914:
3857:
3794:here:
3790:
3748:
3738:
3690:
3562:
3480:MOSFET
3257:where
3210:, and
2504:by an
2486:triode
2430:biased
2351:heated
2092:vacuum
1842:strain
1455:Piston
1055:sthene
1035:scalar
1027:stress
1012:micron
975:
964:
905:" or "
863:newton
859:pascal
817:51.714
671:14.695
660:1.0332
623:14.223
562:14.503
556:750.06
541:1.0197
498:7.5006
487:9.8692
476:1.0197
450:(atm)
444:(bar)
410:Pascal
293:vacuum
89:vacuum
69:liquid
5412:STABL
4885:Loess
4848:Types
4356:(PDF)
4349:(PDF)
4029:(PDF)
3980:(PDF)
3950:(PDF)
3928:S2CID
3886:arXiv
3401:Gauge
3322:) of
3066:force
2871:Fast
2772:Fast
2752:Slow
2620:anode
1884:, an
1720:torrs
1156:gases
1062:kg/cm
1051:pieze
1043:barye
986:diver
971:0.444
969:, or
960:0.030
882:e.g.,
806:0.068
795:0.070
784:0.068
753:0.019
739:0.001
712:0.001
701:0.001
652:1.013
601:0.967
590:0.980
547:0.986
509:0.000
504:Torr
447:(at)
441:(Pa)
372:Units
81:units
65:fluid
63:by a
61:force
5237:Deep
4880:Loam
4875:Peat
4865:Sand
4860:Silt
4855:Clay
4840:Soil
4542:Well
4288:ISBN
4244:ISBN
4217:ISBN
4195:ISBN
4174:ISBN
4082:ISBN
3992:2020
3962:2020
3920:PMID
3912:ISSN
3855:ISSN
3788:ISBN
3746:PMID
3716:2020
3688:ISSN
3640:2016
3596:2016
3579:NIST
3560:ISBN
3023:ASME
2825:drag
2640:Torr
2534:ions
2498:grid
2457:Torr
2426:ions
2390:and
2321:Torr
2240:LVDT
2159:The
2048:Flat
2038:Torr
1702:and
1433:DART
1390:MEMS
1271:CMOS
1182:and
1016:inHg
1008:torr
996:and
926:torr
875:NIST
865:per
853:The
773:.757
679:5142
667:760
631:1203
617:2401
609:3541
493:atm
471:bar
430:Torr
212:and
111:mmHg
5122:Cut
4431:and
3904:doi
3847:doi
3816:doi
3768:HBM
3736:PMC
3728:doi
3680:doi
3021:US
2398:or
2307:or
2141:rad
1899:PPM
1733:).
1729:000
1726:000
1628:hgρ
1619:=
1608:hgρ
1575:hgρ
1362:PPM
1158:or
1146:mm.
1085:or
1047:mts
1039:cgs
1031:kip
1023:atm
977:psi
966:bar
962:643
847:kPa
843:psi
822:572
819:932
811:964
808:045
800:958
797:306
789:573
786:947
778:168
775:293
771:894
758:775
755:336
744:789
741:315
732:760
714:359
706:224
703:333
695:421
692:368
676:775
673:948
645:325
643:101
628:307
625:343
606:105
603:841
592:665
583:066
570:022
567:773
564:773
520:730
517:737
514:037
511:145
482:at
415:Bar
333:of
252:kPa
196:or
121:).
98:or
73:gas
71:or
5529::
5381:*
4137:.
4051:.
4008:.
3982:.
3952:.
3926:.
3918:.
3910:.
3902:.
3894:.
3882:16
3880:.
3876:.
3853:.
3843:36
3841:.
3837:.
3810:.
3766:.
3744:.
3734:.
3726:.
3714:.
3710:.
3686:.
3676:34
3674:.
3670:.
3603:^
3585:^
3554:.
3529:.
3310:A
2883:)
2854:)
2827:)
2642:.
2632:kV
2628:DC
2480:A
2386:.
2374:.
2345:A
2242:,
2042:Pa
1950:cm
1767:A
1652:Hg
1631:.
1626:+
1606:=
1599:−
1573:=
1293:,
1178:,
1174:,
1170:,
1166:,
1150:A
1109:A
973:44
877:.
855:SI
837:A
827:—
749:—
737:≈
717:51
664:—
654:25
650:≡
641:≡
597:—
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