858:), but it can take many years. Movement manufacturers can pre-age crystals before assembling them into clock movements. To promote accelerated aging the crystals are exposed to high temperatures. If a crystal is pre-aged, the manufacturer can measure its aging rates (strictly, the coefficients in the aging formula) and have a microcontroller calculate out the corrections over time. The initial calibration of a movement will stay accurate longer if the crystals are pre-aged. The advantage would end after subsequent regulation which resets any cumulative aging error to zero. A reason more expensive movements tend to be more accurate is that the crystals are pre-aged longer and selected for better aging performance. Sometimes, pre-aged crystals are hand selected for movement performance.
801:. The crystal is deliberately made to run somewhat faster. After manufacturing, each module is calibrated against a precision clock at the factory and adjusted to keep accurate time by programming the digital logic to skip a small number of crystal cycles at regular intervals, such as 10 seconds or 1 minute. For a typical quartz movement, this allows programmed adjustments in 7.91 seconds per 30 days increments for 10-second intervals (on a 10-second measurement gate) or programmed adjustments in 1.32 seconds per 30 days increments for 60-second intervals (on a 60-second measurement gate). The advantage of this method is that using digital programming to store the number of pulses to suppress in a
681:. They are generally found in older, vintage quartz watches – even many of the cheaper ones. A trimmer condenser or variable capacitor changes the frequency coming from the quartz crystal oscillator when its capacitance is changed. The frequency dividers remain unchanged, so the trimmer condenser can be used to adjust the electric pulse-per-second (or other desired time interval) output. The trimmer condenser looks like a small screw that has been wired into the circuit board. Typically, turning the screw clockwise speeds the movement up, and counterclockwise slows it down at about 1 second per day per
1144:. The Astron had a quartz oscillator with a frequency of 8,192 Hz and was accurate to 0.2 seconds per day, 5 seconds per month, or 1 minute per year. The Astron was released less than a year prior to the introduction of the Swiss Beta 21, which was developed by 16 Swiss Watch manufacturers and used by Rolex, Patek and Omega in their electroquartz models. These first quartz watches were quite expensive and marketed as luxury watches. The inherent accuracy and eventually achieved low cost of production have resulted in the proliferation of quartz clocks and watches since that time.
307:(= 2) Hz (high frequency quartz movements) and/or generate digital pulses more than once per second, to drive a stepping motor powered second hand at a higher power of 2 than once every second, but the electric energy consumption (drain on the battery) goes up because higher oscillation frequencies and any activation of the stepping motor costs energy, making such small battery powered quartz watch movements relatively rare. Some analog quartz clocks feature a sweep second hand moved by a non-stepped battery or mains powered electric motor, often resulting in reduced mechanical output noise.
916:
726:
115:
38:
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289:
25:
987:
2605:
131:
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958:
710:
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600:/°C (slower) oscillation rate. So a ±1 °C temperature deviation will account for a (±1) × −0.035 ppm = −0.035 ppm rate change, which is equivalent to −1.1 seconds per year. If, instead, the crystal experiences a ±10 °C temperature deviation, then the rate change will be (±10) × −0.035 ppm = −3.5 ppm, which is equivalent to −110 seconds per year.
596:
fastest is called the "turnover point" and can be chosen within limits. A well-chosen turnover point can minimize the negative effect of temperature-induced frequency drift, and hence improve the practical timekeeping accuracy of a consumer-grade crystal oscillator without adding significant cost. A higher or lower temperature will result in a −0.035
974:
923:) that became the first quartz frequency standard for the United States in 1929. Kept in temperature-controlled ovens to prevent frequency drift due to thermal expansion or contraction of the large quartz resonators (mounted under the glass domes on top of the units) they achieved accuracy of 10, roughly 1 second error in 4 months.
834:(NIST) has published guidelines recommending that these movements keep the time between synchronizations to within ±0.5 seconds to keep time correct when rounded to the nearest second. Some of these movements can keep the time between synchronizations to within ±0.2 seconds by synchronizing more than once spread over a day.
266:(which is essentially two transistors with a bit of cross-connection) which changes from low to high, or vice versa, whenever the line from the crystal goes from high to low. The output from that is fed into a second flip-flop, and so on through a chain of 15 flip-flops, each of which acts as an effective power of 2
166:: that is, when a quartz crystal is subject to mechanical stress, such as bending, it accumulates electrical charge across some planes. In a reverse effect, if charges are placed across the crystal plane, quartz crystals will bend. Since quartz can be directly driven (to flex) by an electric signal, no additional
356:. This frequency is equal to 2 cycles per second. A power of 2 is chosen so a simple chain of digital divide-by-2 stages can derive the 1 Hz signal needed to drive the watch's second hand. In most clocks, the resonator is in a small cylindrical or flat package, about 4 mm to 6 mm long. The
842:
Clock quartz crystals are manufactured in an ultra-clean environment, then protected by an inert ultra-high vacuum in hermetically sealed containers. Despite these measures, the frequency of a quartz crystal can slowly change over time. The effect of aging is much smaller than the effect of frequency
1221:
and low-temperature coefficient of the quartz crystal, they are more accurate than the best mechanical timepieces, and the elimination of all moving parts and significantly lower sensitivity to disturbances from external causes like magnetism and shock makes them more rugged and eliminates the need
595:
The crystal planes and tuning of consumer-grade clock crystal resonators used in wristwatches are designed for minimal temperature sensitivity to frequency and operate best at a temperature range of about 25 to 28 °C (77 to 82 °F). The exact temperature where the crystal oscillates at its
571:
resonators of this type are warranted to have a long-term accuracy of about six parts per million (0.0006%) at 31 °C (87.8 °F): that is, a typical quartz clock or wristwatch will gain or lose 15 seconds per 30 days (within a normal temperature range of 5 to 35 °C or 41 to 95 °F)
902:
almost always decreases with distance, moving an analog quartz clock movement away from an interfering external magnetic source normally results in a resumption of correct mechanical output. Some quartz wristwatch testers feature a magnetic field function to test if the stepping motor can provide
760:
is ±25.55 seconds per year at 23 °C or 73 °F. To acquire the COSC chronometer label, a quartz instrument must benefit from thermo-compensation and rigorous encapsulation. Each quartz chronometer is tested for 13 days, in one position, at 3 different temperatures and 4 different relative
603:
Quartz watch manufacturers use a simplified version of the oven-controlled crystal oscillator method by recommending that their watches be worn regularly to ensure the best time-keeping performance. Regular wearing of a quartz watch significantly reduces the magnitude of environmental temperature
788:
frequency, thermal compensation and hand selecting pre-aged crystals. AT-cut variations allow for greater temperature tolerances, specifically in the range of −40 to 125 °C (−40 to 257 °F), they exhibit reduced deviations caused by gravitational orientation changes. As a result, errors
190:
is often used for laboratory equipment that must not change shape along with the temperature. A quartz plate's resonance frequency, based on its size, will not significantly rise or fall. Similarly, since its resonator does not change shape, a quartz clock will remain relatively accurate as the
822:, to determine how much time the movement gained or lost between time signal receptions, and adjustments are made to the circuitry to "regulate" the timekeeping, then the corrected time will be accurate within ±1 second per year. This is more than adequate to perform longitude determination by
805:
register on the chip is less expensive than the older technique of trimming the quartz tuning-fork frequency. The inhibition-compensation logic of some quartz movements can be regulated by service centers with the help of a professional precision timer and adjustment terminal after leaving the
1150:
introduced the
Caliber 350 in 1971, with an advertised accuracy within about 0.164 seconds per day, which had a quartz oscillator with a frequency of 32,768 Hz, which was faster than previous quartz watch movements and has since become the oscillation frequency used by most quartz clocks. The
228:
The frequency at which the crystal oscillates depends on its shape, size, and the crystal plane on which the quartz is cut. The positions at which electrodes are placed can slightly change the tuning as well. If the crystal is accurately shaped and positioned, it will oscillate at a desired
903:
mechanical output and let the gear train and hands deliberately spin overly fast to clear minor fouling. In general, magnetism encountered in daily life has no effect on digital quartz clock movements since there are no stepping motors in these movements. Powerful magnetism sources like
742:
It is possible for a computerized high-accuracy quartz movement to measure its temperature and adjust for that. For this the movement autonomously measures the crystal's temperature a few hundred to a few thousand times a day and compensates for this with a small calculated offset. Both
1642:
661:(or another starting point) is accurately enough known, celestial navigation can determine longitude, and the more accurately time is known the more accurate the latitude determination. At latitude 45° one second of time is equivalent in longitude to 1,077.8
221:, eliminating all but the single frequency of interest. The output of the resonator feeds back to the input of the amplifier, and the resonator assures that the oscillator runs at the exact frequency of interest. When the circuit is powered up, a single burst of
588:, temperature changes are the major cause of frequency variation in crystal oscillators. The most obvious way of reducing the effect of temperature on the oscillation rate is to keep the crystal at a constant temperature. For laboratory-grade oscillators, an
621:
set at the factory, and the most recent time the clock was set. Clocks that are sometimes regulated by service centers with the help of a precision timer and adjustment terminal after leaving the factory, also become more accurate as their quartz crystal
751:
temperature compensation have been used in high-end quartz watches. In more expensive high-end quartz watches, thermal compensation can be implemented by varying the number of cycles to inhibit depending on the output from a temperature sensor. The
761:
humidity levels. Only approximately 0.2% of the Swiss made quartz watches are chronometer-certified by the COSC. These COSC chronometer-certified movements can be used as marine chronometers to determine longitude by means of celestial navigation.
1995:
1638:
1045:. The 1927 clock used a block of crystal, stimulated by electricity, to produce pulses at a frequency of 50,000 cycles per second. A submultiple controlled frequency generator then divided this down to a usable, regular pulse that drove a
470:
1609:
616:
Some movement designs feature accuracy-enhancing features or self-rate and self-regulate. That is, rather than just counting vibrations, their computer program takes the simple count and scales it using a ratio calculated between an
1417:
The absolute threshold usually starts to increase sharply when the signal frequency exceeds about 15 kHz. ... The present results show that some humans can perceive tones up to at least 28 kHz when their level exceeds about 100 dB
319:
Picture of a quartz crystal resonator, used as the timekeeping component in quartz watches and clocks, with the case removed. It is formed in the shape of a tuning fork. Most such quartz clock crystals vibrate at a frequency of
854:, meaning the maximum rate of change of frequency occurs immediately after manufacture and decays thereafter. Most of the aging will occur within the first year of the crystal's service life. Crystals do eventually stop aging (
843:
variation caused by temperature changes, however, and manufacturers can estimate its effects. Generally, the aging effect eventually decreases a given crystal's frequency but it can also increase a given crystal's frequency.
1088:
Their inherent physical and chemical stability and accuracy have resulted in the subsequent proliferation, and since the 1940s they have formed the basis for precision measurements of time and frequency worldwide.
178:
cartridges: The movement of the stylus (needle) flexes a quartz crystal, which produces a small voltage, which is amplified and played through speakers. Quartz microphones are still available, though not common.
1991:
2309:
Koga, Issac; Aruga, Masanao; Yoshinaka, Yōichirō (1958). "Theory of Plane
Elastic Waves in a Piezoelectric Crystalline Medium and Determination of Elastic and Piezoelectric Constants of Quartz".
225:(always present in electronic circuits) can cascade to bring the oscillator into oscillation at the desired frequency. If the amplifier were perfectly noise-free, the oscillator would not start.
1175:(LED) displays for watches have become rare due to their comparatively high battery consumption. These innovations made the technology suitable for mass market adoption. In laboratory settings
1728:
592:
is used, in which the crystal is kept in a very small oven that is held at a constant temperature. This method is, however, impractical for consumer quartz clock and wristwatch movements.
773:
became commercially available which is claimed to be accurate to ± 1 second per year. Key elements to obtain the high claimed accuracy are applying an unusually shaped (for a watch) (
1112:'s 1966 competition. In 1967, both the CEH and Seiko presented prototypes of quartz wristwatches to the Neuchâtel Observatory competition. The world's first prototype analog quartz
898:
output. As a result, the mechanical output of analog quartz clock movements may temporarily stop, advance or reverse and negatively impact correct timekeeping. As the strength of a
1056:, limited their use elsewhere. In 1932 a quartz clock was able to measure tiny variations in the rotation rate of the Earth over periods as short as a few weeks. In Japan in 1932,
102:
digital electronics allowed them to be made compact and inexpensive, quartz timekeepers have become the world's most widely used timekeeping technology, used in most clocks and
1518:
Itoh H, Aoshima Y, Sakaguchi Y (2002). "Model for a quartz-crystal tuning fork using plate spring approximated to torsion spring adopted at the joint of the arm and the base".
2928:
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found in the early 1920s that quartz can resonate with less equipment and better temperature stability, steel resonators disappeared within a few years. Later, scientists at
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255:, cost and size at a modest level and to permit inexpensive counters to derive a 1-second pulse. The data line output from such a quartz resonator goes high and low
393:
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in 1919; his achievement removed much of the damping associated with mechanical devices and maximised the stability of the vibration's frequency. The first quartz
850:, moisture absorption, changes in or on the quartz crystal, severe shock and vibrations effects, and exposure to very high temperatures. Crystal aging tends to be
281:
output can be used to drive many kinds of clocks. In analog quartz clocks and wristwatches, the electric pulse-per-second output is nearly always transferred to a
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138:, left: button cell watch battery, top right: oscillator counter, digital frequency divider and driver for the stepping motor (under black epoxy), top left: the
2020:
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The next 3 decades saw the development of quartz clocks as precision time standards in laboratory settings; the bulky delicate counting electronics, built with
1023:
1774:
2101:
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In the early 20th century, radio engineers sought a precise, stable source of radio frequencies and started at first with steel resonators. However, when
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resonator has become so common due to a compromise between the large physical size of low-frequency crystals for watches and the larger current drain of
826:. These quartz movements over time become less accurate when no external time signal has been successfully received and internally processed to set or
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used in analog quartz clock movements which themselves are driven by a magnetic field (generated by the coil) can be affected by external (nearby)
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Factors that can cause a small frequency drift over time are stress relief in the mounting structure, loss of hermetic seal, contamination of the
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Developing quartz clocks for the consumer market took place during the 1960's. One of the first successes was a portable quartz clock called the
2876:
1920:
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developed a crystal cut that gave an oscillation frequency with greatly reduced temperature dependence. The
National Bureau of Standards (now
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turn of the screw. Few newer quartz movement designs feature a mechanical trimmer condenser and rely on generally digital correction methods.
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1535:
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were revealed in 1967: the Beta 1 revealed by the Centre
Electronique Horloger (CEH) in Neuchâtel Switzerland, and the prototype of the
1438:(= 2) Hz sweep second (analog second hand driven in 0.125 s increments) quartz watch movement Bulova Caliber 8136 at calibercorner.com"
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2680:
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1703:
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547:/m) with a length of 3mm and a thickness of 0.3mm has thus a fundamental frequency around 33 kHz. The crystal is tuned to exactly 2 =
2292:
1967:
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The relative stability of the quartz resonator and its driving circuit is much better than its absolute accuracy. Standard-quality
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that converts the electronic input pulses from the flip-flops counting unit into mechanical output that can be used to move hands.
830:
their time automatically, and without such external compensation generally fall back on autonomous timekeeping. The United States
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1610:"Using the typical temperature characteristics of 32 KHz crystal to compensate the M41T83 and the M41T93 serial real-time clocks"
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1664:"Errors in Longitude, Latitude and Azimuth Determinations-I by F.A. McDiarmid, The Royal Astronomical Society of Canada, 1914"
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was invented in 1912. An electrical oscillator was first used to sustain the motion of a tuning fork by the
British physicist
3384:
2921:
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1243:
1441:
874:, to keep the crystal at a constant temperature. Some self-rate and include "crystal farms", so that the clock can take the
3980:
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that uses the stable temperature of the human body to keep the crystal oscillator in its most accurate temperature range.
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126:
and connected white and transparent gears (right). These gears control the movement of the second, minute and hour hands.
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240:, and the crystal is cut in a small tuning fork shape on a particular crystal plane. This frequency is a power of two (
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1943:
1042:
1031:
252:
2016:
1917:"Citizen unveils world's most accurate Cal.0100 Eco-Drive movement with annual accuracy ±1 second at BASELWORLD 2018"
1321:
1064:) based the time standard of the US on quartz clocks between the 1930s and the 1960s, after which it transitioned to
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300:
It is also possible for quartz clocks and watches to have their quartz crystal oscillate at a higher frequency than
3110:
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1081:
1072:
deployed the first quartz movement. The wider use of quartz clock technology had to await the development of cheap
1007:
904:
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with 4 area radio time signal reception (North
America, Europe, China, Japan) and radio-controlled synchronization
277:
counter driven by the frequency that will overflow once per second, creating a digital pulse once per second. The
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202:(then the U.S. National Bureau of Standards) discovered that a crystal oscillator could be more accurate than a
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1109:
1520:
Proceedings of the 2002 IEEE International
Frequency Control Symposium and PDA Exhibition (Cat. No.02CH37234)
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The
Restoration Of The Girard-Perregaux Caliber 350, The Most Important Quartz Watch You've Never Heard Of
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had replaced quartz clocks as the basis for precision measurements of time and frequency, resulting in
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Regardless of the precision of the oscillator, a quartz analog or digital watch movement can have a
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in Japan (Seiko had been working on quartz clocks since 1958). The first Swiss quartz watch – the
927:
91:. Generally, some form of digital logic counts the cycles of this signal and provides a numerical
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at Bell Labs in 1927. A vacuum tube oscillator controlled by the 100 kHz quartz crystal (
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1463:"TMI VH31 sweep second (analog second hand driven in 0.25 s increments) quartz watch movement"
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465:{\displaystyle f={\frac {1.875104^{2}}{2\pi }}{\frac {a}{l^{2}}}{\sqrt {\frac {E}{12\rho }}},}
288:
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stated that quartz clocks would probably never be affordable enough to be used domestically.
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If a quartz movement is daily "rated" by measuring its timekeeping characteristics against a
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1639:"Introduction to Quartz Frequency Standards – Static Frequency versus Temperature Stability"
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that can be precisely controlled, properties that allow them to have a remarkable degree of
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Many inexpensive quartz clocks and watches use a rating and compensation technique known as
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2476:"The Quartz Crisis and Recovery of Swiss Watches | Relation between Timepieces and Society"
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1229:(RTC) crystal units have become cheap mass-produced items on the electronic parts market.
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24:
2413:. Time and Frequency Division, National Institute of Standards and Technology. p. 5.
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factory, though many inexpensive quartz watch movements do not offer this functionality.
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633:, can be accurate to within ±1 to ±25 seconds per year and can be certified and used as
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Marrison, W. A.; J. W. Horton (February 1928). "Precision determination of frequency".
1842:"Crisis? What crisis? A short history of high-frequency, super-accurate quartz watches"
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In
October 1927 the first quartz clock was described and built by Joseph W. Horton and
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1771:"In Pursuit of Perfection : Thermocompensated Quartz Watches and Their Movements"
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Four precision 100 kHz quartz oscillators at the US Bureau of
Standards (now
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or runs at a slightly higher frequency with inhibition compensation (see below).
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1817:"Citizen Unveils Cal.0100 Eco-Drive Movement With Annual Accuracy Of ±1 Second"
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By the 1980s, quartz technology had taken over applications such as kitchen
1160:
1096:. This portable clock was used as a backup timer for marathon events in the
1019:
891:
770:
638:
333:
214:
171:
159:
118:
Disassembled analog quartz clockwork; quartz crystal oscillator (top left),
72:
2815:
1940:
1412:
270:
by dividing the frequency of the input signal by 2. The result is a 15-bit
217:
whose output passes through the quartz resonator. The resonator acts as an
2407:
1561:"Vibrations of Cantilever Beams: Deflection, Frequency, and Research Uses"
1318:
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3218:
3210:
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1218:
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544:
479:
1.875104 (rounded) is the smallest positive solution of the equation cos(
789:
caused by spatial orientation and positioning become less of a concern.
626:
and somewhat unpredictable aging effects are appropriately compensated.
182:
Quartz has a further advantage in that its size does not change much as
3796:
3786:
3708:
3699:
3684:
3586:
3571:
3416:
3339:
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1034:
produced sequences of precision time signals with quartz oscillators.
875:
719:
giving an accuracy better than ± 5 seconds per year, French Navy issued
516:
2728:"Four Revolutions: Part 1: A Concise History Of The Quartz Revolution"
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frequency. In nearly all quartz clocks and watches, the frequency is
151:
64:
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1751:"High accuracy timepieces that could be used as marine chronometer"
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36:
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First quartz wristwatch movement, Caliber 35A, Seiko, Japan, 1969
931:
One of the first experimental quartz controlled clocks, built by
604:
swings, since a correctly designed watch case forms an expedient
3043:
3029:
2634:
1199:
1061:
753:
669:), or one-tenth of a second means 107.8 ft (32.86 m).
646:
642:
199:
92:
3002:
2910:
1217:
and domestic clock market since the 1980s. Because of the high
2073:"Is The Citizen Caliber 0100 The World's Most Accurate Watch?"
1867:"Is The Citizen Caliber 0100 The World's Most Accurate Watch?"
2603:
Timepieces: masterpieces of chronometry By David Christianson
2408:"Time and frequency measurement at NIST: The first 100 years"
1136:
produced the world's first commercial quartz wristwatch, the
387:
as a function of its dimensions (quadratic cross-section) is
332:
In modern standard-quality quartz clocks, the quartz crystal
2344:
Koga, I. (1936). "Notes on Piezoelectric Quartz Crystals".
1027:
2157:
2155:
1100:
in Tokyo. In 1966, prototypes of the world's first quartz
994:
The piezoelectric properties of quartz were discovered by
106:
as well as computers and other appliances that keep time.
95:
display, usually in units of hours, minutes, and seconds.
2902:
Introduction to Quartz Frequency Standards by John R. Vig
2877:
Modern quartz "analog" clocks and watches with animations
2867:
TimeZone.com article on the development of quartz watches
963:
First European quartz clock for consumers "Astrochron",
939:) is divided down by vacuum tube counters and runs the
2998:
134:
Basic quartz wristwatch movement. Bottom right: quartz
2751:
Watch Collector on a Budget? Start With Vintage Quartz
2581:
Federation of the Swiss Watch Industry. Archived from
2266:
2264:
2558:
Engineering time: inventing the electronic wristwatch
1892:"Crystal Units / Crystal Oscillators Technical Guide"
396:
158:. Many materials can be formed into plates that will
2530:"Fifty years of the quartz wristwatch – FHH Journal"
2017:"Introduction to Quartz Frequency Standards - Aging"
1992:"Introduction to Quartz Frequency Standards – Aging"
715:
Omega 4.19 MHz high frequency quartz resonator
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2944:
1797:"High Accuracy Wristwatches as Marine Chronometers"
1725:"Interview de Pierre-Yves Soguel Directeur du COSC"
1206:movements, an upheaval known in watchmaking as the
629:Autonomous high-accuracy quartz movements, even in
464:
2804:Notes and Records of the Royal Society of London
2713:"Milestones: Electronic Quartz Wristwatch, 1969"
1563:. University of Nebraska–Lincoln. Archived from
1375:The Journal of the Acoustical Society of America
1287:Quartz resonators can vibrate with very a small
48:-wristwatch. Quartz oscillator crystal on right.
2123:"MRI Safe Watches that are within your budget!"
1961:"Radio-Controlled Wallclock Instruction Manual"
1371:"Hearing thresholds for pure tones above 16kHz"
1079:in the 1960s. The revised 1929 14th edition of
499:is its thickness along the direction of motion,
1319:"The Accuracy and Stability of Quartz Watches"
1159:allowed a 12-month battery life from a single
832:National Institute of Standards and Technology
200:National Institute of Standards and Technology
3014:
2922:
2802:Cook A (2001). "Time and the Royal Society".
1339:"Introduction of Tuning Fork Quartz Crystals"
1167:, a smooth sweeping non-stepping motor, or a
758:officially certified COSC quartz chronometers
336:or oscillator is cut in the shape of a small
8:
2681:"Revisiting Time at the 1964 Tokyo Olympics"
2579:"From the roots until today's achievements."
2833:"The Evolution of the quartz crystal clock"
2273:"The Evolution of the Quartz Crystal Clock"
2235:"The Evolution of the Quartz Crystal Clock"
1941:"How Accurate is a Radio Controlled Clock?"
870:designed as time standards often include a
348:-trimmed or precision lapped to vibrate at
3704:
3078:
3021:
3007:
2999:
2929:
2915:
2907:
2872:Explain That Stuff: How quartz clocks work
1488:"Tuning Fork Crystal Unit (Cylinder Type)"
1314:
1312:
943:on front. Accuracy was 0.01 second per day
2623:"First-Hand:The First Quartz Wrist Watch"
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623:
442:
434:
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409:
403:
395:
2897:A short primer on AT-cut quartz crystals
2649:"Seiko Quartz Astron 35SQ December 1969"
2457:
2185:
2173:
2161:
2146:
769:As of 2019, an autonomous light-powered
368:crystals, which reduces the life of the
296:decreases the frequency by a factor of 2
154:is a specific form of a compound called
2551:
2549:
1308:
1280:
174:. Similar crystals are used in low-end
2952:Synchronous Motor and the Master Clock
1202:on munitions, from earlier mechanical
375:The basic formula for calculating the
1688:Transistor Crystal Oscillator Circuit
1213:Quartz timepieces have dominated the
765:Additional accuracy enhancing methods
247:= 2), just high enough to exceed the
7:
3955:
2098:"How does magnetism affect a watch?"
98:Since the 1980s, when the advent of
2555:Carlene Stephens and Maggie Dennis
990:A quartz clock hung on a wall, 2005
907:can damage quartz clock movements.
771:high-accuracy quartz watch movement
580:Temperature and frequency variation
262:times a second. This is fed into a
71:creates a signal with very precise
2849:10.1002/j.1538-7305.1948.tb01343.x
2726:Thompson, Joe (October 10, 2017).
2251:10.1002/j.1538-7305.1948.tb01343.x
777:) quartz crystal operated at 2 or
590:oven-controlled crystal oscillator
14:
1163:when driving either a mechanical
1151:introduction during the 1970s of
950:Early quartz clocks for consumers
894:sources, and this may impact the
576:per day when worn near the body.
3954:
3945:
3944:
2382:Advanced Piezoelectric Materials
1094:Seiko Crystal Chronometer QC-951
972:
956:
756:average daily rate standard for
724:
708:
586:coefficient of thermal expansion
493:is the length of the cantilever,
23:
2780:from the original on 2021-10-24
2511:from the original on 2022-01-29
2129:from the original on 2022-01-22
2104:from the original on 2022-01-21
2079:from the original on 2020-08-06
2054:from the original on 2020-08-06
2023:from the original on 2019-06-17
1998:from the original on 2021-07-10
1973:from the original on 2021-10-16
1923:from the original on 2018-04-25
1898:from the original on 2018-06-12
1873:from the original on 2020-08-06
1848:from the original on 2021-07-26
1823:from the original on 2018-04-25
1777:from the original on 2012-11-04
1731:from the original on 2010-12-08
1706:from the original on 2019-08-26
1670:from the original on 2021-10-16
1645:from the original on 2021-07-17
1500:from the original on 2021-11-27
1469:from the original on 2020-11-11
1444:from the original on 2022-01-26
1351:from the original on 2021-05-08
878:of a set of time measurements.
810:External time signal correction
702:Accuracy-enhanced quartz clocks
2679:Fowler, Susanne (2021-07-23).
1369:Ashihara, Kaoru (2007-09-01).
1244:Crystal oscillator frequencies
1128:Beta 21 – arrived at the 1970
882:External magnetic interference
1:
2837:Bell System Technical Journal
2638:Global History Network, 2009.
2505:"1969: Seiko's Breakout Year"
2406:Sullivan, D. B. (2001).
2239:Bell System Technical Journal
1559:Whitney, Scott (1999-04-23).
584:Though quartz has a very low
209:The electronic circuit is an
2892:Horology 101 - quartz F.A.Q.
1024:National Physical Laboratory
162:. However, quartz is also a
146:that powers the watch hands.
3759:Geological history of Earth
2774:"Tuning Fork Crystal Units"
2534:journal.hautehorlogerie.org
2427:Watches: Warman's Companion
1950:by Michael Lombardi (2010).
1328:by Michael Lombardi (2008).
1171:(in an LCD digital watch).
1104:were unveiled by Seiko and
1043:Bell Telephone Laboratories
1032:Bell Telephone Laboratories
649:position of a point on the
572:or less than a half second
253:electric energy consumption
170:is required to use it in a
67:crystal to keep time. This
59:are timepieces that use an
4002:
3111:Orders of magnitude (time)
2358:10.1109/JRPROC.1936.226840
2212:10.1109/JRPROC.1928.221372
1222:for periodic maintenance.
1140:which is now honored with
888:Lavet-type stepping motors
3940:
3822:Time translation symmetry
2938:Electric clock technology
2385:. Elsevier. p. 174.
2233:Marrison, Warren (1948).
1528:10.1109/FREQ.2002.1075871
1264:Lavet-type stepping motor
1181:International Atomic Time
1165:Lavet-type stepping motor
1153:metal–oxide–semiconductor
283:Lavet-type stepping motor
251:, yet low enough to keep
120:Lavet-type stepping motor
2331:10.1103/PhysRev.109.1467
2245:(3). AT&T: 510–588.
1138:Seiko Quartz-Astron 35SQ
717:Ships Marine Chronometer
653:'s surface) by means of
30:Modern quartz wristwatch
3777:Absolute space and time
3428:Astronomical chronology
2883:How Quartz Watches Work
2430:. Iola, WI: F+W Media.
2042:"Quartz Crystal Ageing"
1700:"COSC quartz movements"
1082:Encyclopædia Britannica
1030:and Warren Marrison at
799:inhibition compensation
793:Inhibition compensation
731:Citizen analog-digital
3986:Electronic oscillators
3827:Time reversal symmetry
3131:Italian six-hour clock
2945:Powerline synchronized
2816:10.1098/rsnr.2001.0123
2346:Proceedings of the IRE
2200:Proceedings of the IRE
1619:. STMicroelectronics -
1169:liquid-crystal display
1004:vacuum tube oscillator
991:
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924:
466:
329:
297:
164:piezoelectric material
147:
127:
49:
3592:Time and fate deities
3537:The Unreality of Time
3476:A series and B series
1110:Neuchâtel Observatory
989:
930:
918:
820:satellite time signal
523:A cantilever made of
467:
377:fundamental frequency
318:
291:
191:temperature changes.
133:
117:
61:electronic oscillator
44:of an e block from a
40:
3981:Movement (clockwork)
3843:Chronological dating
3812:Theory of relativity
3156:Daylight saving time
2881:Douglas Dwyer.
2831:Marrison WA (1948).
2507:. 20 December 2009.
1522:. pp. 145–151.
1225:Standard 'Watch' or
1173:Light-emitting diode
1132:. In December 1969,
1098:1964 Summer Olympics
838:Quartz crystal aging
824:celestial navigation
695:Thermal compensation
655:celestial navigation
612:Accuracy enhancement
394:
383:) of vibration of a
122:(left) with a black
3136:Thai six-hour clock
2715:. 31 December 2015.
2460:, pp. 531–532.
2424:Judy, Dean (2008).
2379:Uchino, K. (2010).
2323:1958PhRv..109.1467K
1844:. 17 October 2019.
1586:"density of quartz"
1387:2007ASAJ..122L..52A
1293:frequency stability
1249:Solar-powered watch
1157:integrated circuits
803:non-volatile memory
657:. When time at the
635:marine chronometers
249:human hearing range
87:more accurate than
3666:Rosy retrospection
3644:Mental chronometry
3468:Philosophy of time
2685:The New York Times
2628:2014-03-27 at the
2608:2022-12-05 at the
2564:2017-12-01 at the
2295:2011-07-17 at the
1946:2021-10-16 at the
1588:. Wolframalpha.com
1324:2017-12-13 at the
1039:Warren A. Marrison
1018:in 1921. In 1923,
1012:crystal oscillator
992:
967:, Schramberg, 1967
945:
925:
462:
330:
298:
196:Walter Guyton Cady
148:
136:crystal oscillator
128:
85:order of magnitude
69:crystal oscillator
50:
3968:
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3878:
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3853:Circadian rhythms
3671:Tense–aspect–mood
3526:Temporal finitism
3403:
3402:
3379:Grandfather clock
2996:
2995:
2962:Synchronous motor
2957:Utility frequency
2392:978-1-84569-534-7
1819:. 21 March 2018.
1749:Read, Alexander.
1537:978-0-7803-7082-1
1396:10.1121/1.2761883
1269:Pierce oscillator
1047:synchronous motor
941:synchronous clock
937:under dome at top
816:radio time signal
679:trimmer condenser
673:Trimmer condenser
457:
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268:frequency divider
219:electronic filter
89:mechanical clocks
75:, so that quartz
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3865:Glottochronology
3705:
3621:Human experience
3481:B-theory of time
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2851:. Archived from
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2654:. Archived from
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2621:Frei, Armin H.,
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2480:The Seiko Museum
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2317:(5): 1467–1473.
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2271:Marrison, W. A.
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2253:. Archived from
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1381:(3): EL52–EL57.
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1239:Automatic quartz
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3927:Time immemorial
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3717:Geological time
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3676:Time management
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2796:Further reading
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1227:Real-time clock
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933:Warren Marrison
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848:crystal lattice
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63:regulated by a
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3870:Time geography
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3860:Clock reaction
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3501:Eternal return
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3404:
3401:
3400:
3398:
3397:
3396:
3395:
3381:
3376:
3371:
3366:
3365:
3364:
3359:
3358:
3357:
3352:
3342:
3337:
3332:
3327:
3326:
3325:
3315:
3314:
3313:
3297:
3295:
3289:
3288:
3286:
3285:
3278:
3273:
3271:Hindu Panchang
3268:
3263:
3258:
3253:
3248:
3243:
3238:
3237:
3236:
3231:
3226:
3215:
3213:
3207:
3206:
3204:
3203:
3198:
3193:
3188:
3183:
3178:
3173:
3168:
3163:
3158:
3153:
3148:
3143:
3138:
3133:
3127:
3125:
3117:
3116:
3114:
3113:
3108:
3103:
3098:
3093:
3087:
3085:
3076:
3065:
3064:
3062:
3061:
3056:
3051:
3046:
3040:
3038:
3034:
3033:
3028:
3026:
3025:
3018:
3011:
3003:
2994:
2993:
2991:
2990:
2985:
2980:
2974:
2972:
2968:
2967:
2965:
2964:
2959:
2954:
2948:
2946:
2942:
2941:
2936:
2934:
2933:
2926:
2919:
2911:
2905:
2904:
2899:
2894:
2889:
2879:
2874:
2869:
2862:
2861:External links
2859:
2858:
2857:
2855:on 2007-05-13.
2843:(3): 510–588.
2828:
2797:
2794:
2791:
2790:
2765:
2754:
2743:
2718:
2704:
2671:
2640:
2614:
2595:
2570:
2545:
2521:
2491:
2462:
2450:
2436:
2416:
2398:
2391:
2371:
2352:(3): 510–531.
2336:
2301:
2282:
2260:
2257:on 2007-05-13.
2225:
2206:(2): 137–154.
2190:
2188:, p. 533.
2178:
2176:, p. 538.
2166:
2164:, p. 527.
2151:
2149:, p. 526.
2139:
2114:
2089:
2064:
2033:
2008:
1983:
1952:
1933:
1908:
1883:
1858:
1833:
1808:
1787:
1762:
1741:
1716:
1691:
1680:
1655:
1630:
1598:
1577:
1551:
1536:
1510:
1479:
1454:
1422:
1361:
1330:
1307:
1306:
1304:
1301:
1298:
1297:
1279:
1278:
1276:
1273:
1272:
1271:
1266:
1261:
1256:
1254:Electric watch
1251:
1246:
1241:
1234:
1231:
1142:IEEE Milestone
1016:Walter G. Cady
1008:William Eccles
978:
971:
970:
962:
955:
954:
953:
949:
948:
947:
946:
912:
909:
900:magnetic field
896:rotor sprocket
883:
880:
863:
860:
856:asymptotically
839:
836:
811:
808:
794:
791:
766:
763:
730:
723:
722:
714:
707:
706:
705:
701:
700:
699:
698:
696:
693:
674:
671:
659:prime meridian
613:
610:
581:
578:
560:
557:
521:
520:
510:
500:
494:
488:
473:
472:
461:
454:
451:
447:
437:
433:
429:
421:
418:
412:
408:
402:
399:
366:high-frequency
312:
309:
204:pendulum clock
124:rotor sprocket
111:
108:
57:quartz watches
29:
22:
21:
20:
19:
18:
15:
13:
10:
9:
6:
4:
3:
2:
3998:
3987:
3984:
3982:
3979:
3978:
3976:
3961:
3953:
3951:
3943:
3942:
3939:
3933:
3930:
3928:
3925:
3923:
3920:
3918:
3917:
3913:
3911:
3908:
3906:
3903:
3901:
3898:
3896:
3893:
3891:
3888:
3887:
3885:
3881:
3871:
3868:
3866:
3863:
3861:
3858:
3854:
3851:
3850:
3849:
3848:Chronobiology
3846:
3844:
3841:
3840:
3838:
3834:
3828:
3825:
3823:
3820:
3818:
3815:
3813:
3810:
3808:
3805:
3803:
3800:
3798:
3795:
3793:
3790:
3788:
3785:
3783:
3782:Arrow of time
3780:
3778:
3775:
3774:
3772:
3770:
3766:
3760:
3757:
3755:
3754:Geochronology
3752:
3748:
3745:
3743:
3740:
3738:
3735:
3733:
3730:
3728:
3725:
3723:
3720:
3719:
3718:
3715:
3714:
3712:
3710:
3706:
3703:
3701:
3696:
3690:
3686:
3682:
3679:
3677:
3674:
3672:
3669:
3667:
3664:
3660:
3657:
3655:
3652:
3651:
3650:
3647:
3645:
3642:
3640:
3637:
3635:
3632:
3631:
3629:
3627:
3622:
3618:
3610:
3607:
3606:
3605:
3604:Wheel of time
3602:
3598:
3595:
3594:
3593:
3590:
3588:
3585:
3583:
3580:
3578:
3575:
3573:
3570:
3568:
3565:
3564:
3562:
3557:
3554:
3552:
3549:
3548:
3545:
3539:
3538:
3534:
3532:
3529:
3527:
3524:
3522:
3519:
3517:
3514:
3512:
3509:
3507:
3504:
3502:
3499:
3497:
3494:
3492:
3489:
3487:
3484:
3482:
3479:
3477:
3474:
3473:
3471:
3469:
3465:
3459:
3456:
3454:
3451:
3449:
3448:Periodization
3446:
3444:
3441:
3439:
3436:
3434:
3431:
3429:
3426:
3425:
3423:
3418:
3415:
3413:
3410:
3409:
3406:
3394:
3393:
3389:
3388:
3387:
3386:
3382:
3380:
3377:
3375:
3374:Digital clock
3372:
3370:
3367:
3363:
3360:
3356:
3353:
3351:
3348:
3347:
3346:
3343:
3341:
3338:
3336:
3333:
3331:
3328:
3324:
3321:
3320:
3319:
3316:
3312:
3309:
3308:
3307:
3304:
3303:
3302:
3299:
3298:
3296:
3294:
3290:
3284:
3283:
3279:
3277:
3274:
3272:
3269:
3267:
3264:
3262:
3259:
3257:
3254:
3252:
3249:
3247:
3244:
3242:
3239:
3235:
3232:
3230:
3227:
3225:
3222:
3221:
3220:
3217:
3216:
3214:
3212:
3208:
3202:
3199:
3197:
3194:
3192:
3189:
3187:
3184:
3182:
3179:
3177:
3174:
3172:
3169:
3167:
3164:
3162:
3159:
3157:
3154:
3152:
3151:Relative hour
3149:
3147:
3146:24-hour clock
3144:
3142:
3141:12-hour clock
3139:
3137:
3134:
3132:
3129:
3128:
3126:
3124:
3118:
3112:
3109:
3107:
3104:
3102:
3099:
3097:
3094:
3092:
3089:
3088:
3086:
3084:
3080:
3077:
3075:
3070:
3066:
3060:
3057:
3055:
3052:
3050:
3047:
3045:
3042:
3041:
3039:
3035:
3031:
3024:
3019:
3017:
3012:
3010:
3005:
3004:
3001:
2989:
2986:
2984:
2981:
2979:
2976:
2975:
2973:
2969:
2963:
2960:
2958:
2955:
2953:
2950:
2949:
2947:
2943:
2939:
2932:
2927:
2925:
2920:
2918:
2913:
2912:
2909:
2903:
2900:
2898:
2895:
2893:
2890:
2888:
2887:HowStuffWorks
2884:
2880:
2878:
2875:
2873:
2870:
2868:
2865:
2864:
2860:
2854:
2850:
2846:
2842:
2838:
2834:
2829:
2825:
2821:
2817:
2813:
2809:
2805:
2800:
2799:
2795:
2779:
2775:
2769:
2766:
2763:
2758:
2755:
2752:
2747:
2744:
2733:
2729:
2722:
2719:
2714:
2708:
2705:
2694:
2690:
2686:
2682:
2675:
2672:
2661:on 2022-03-16
2657:
2650:
2644:
2641:
2637:
2636:
2631:
2627:
2624:
2618:
2615:
2611:
2607:
2604:
2599:
2596:
2585:on 2007-11-28
2584:
2580:
2574:
2571:
2567:
2563:
2560:
2559:
2552:
2550:
2546:
2535:
2531:
2525:
2522:
2510:
2506:
2500:
2498:
2496:
2492:
2481:
2477:
2471:
2469:
2467:
2463:
2459:
2458:Marrison 1948
2454:
2451:
2439:
2437:9781440219085
2433:
2429:
2428:
2420:
2417:
2409:
2402:
2399:
2394:
2388:
2384:
2383:
2375:
2372:
2367:
2363:
2359:
2355:
2351:
2347:
2340:
2337:
2332:
2328:
2324:
2320:
2316:
2312:
2305:
2302:
2298:
2294:
2291:
2286:
2283:
2278:
2274:
2267:
2265:
2261:
2256:
2252:
2248:
2244:
2240:
2236:
2229:
2226:
2221:
2217:
2213:
2209:
2205:
2201:
2194:
2191:
2187:
2186:Marrison 1948
2182:
2179:
2175:
2174:Marrison 1948
2170:
2167:
2163:
2162:Marrison 1948
2158:
2156:
2152:
2148:
2147:Marrison 1948
2143:
2140:
2128:
2124:
2118:
2115:
2103:
2099:
2093:
2090:
2078:
2074:
2068:
2065:
2050:
2043:
2037:
2034:
2022:
2018:
2012:
2009:
1997:
1993:
1987:
1984:
1969:
1962:
1956:
1953:
1949:
1945:
1942:
1937:
1934:
1922:
1918:
1912:
1909:
1897:
1893:
1887:
1884:
1872:
1868:
1862:
1859:
1847:
1843:
1837:
1834:
1822:
1818:
1812:
1809:
1798:
1791:
1788:
1776:
1772:
1766:
1763:
1752:
1745:
1742:
1730:
1726:
1720:
1717:
1705:
1701:
1695:
1692:
1689:
1684:
1681:
1669:
1665:
1659:
1656:
1644:
1640:
1634:
1631:
1618:
1611:
1605:
1603:
1599:
1587:
1581:
1578:
1567:on 2011-10-31
1566:
1562:
1555:
1552:
1547:
1543:
1539:
1533:
1529:
1525:
1521:
1514:
1511:
1496:
1489:
1483:
1480:
1468:
1464:
1458:
1455:
1443:
1439:
1426:
1423:
1419:
1414:
1410:
1406:
1402:
1397:
1392:
1388:
1384:
1380:
1376:
1372:
1365:
1362:
1347:
1340:
1334:
1331:
1327:
1323:
1320:
1315:
1313:
1309:
1302:
1294:
1290:
1284:
1281:
1274:
1270:
1267:
1265:
1262:
1260:
1259:Quartz crisis
1257:
1255:
1252:
1250:
1247:
1245:
1242:
1240:
1237:
1236:
1232:
1230:
1228:
1223:
1220:
1216:
1211:
1209:
1208:quartz crisis
1205:
1204:balance wheel
1201:
1197:
1194:, bank vault
1193:
1189:
1184:
1182:
1178:
1177:atomic clocks
1174:
1170:
1166:
1162:
1158:
1154:
1149:
1145:
1143:
1139:
1135:
1131:
1127:
1123:
1119:
1115:
1111:
1107:
1103:
1099:
1095:
1090:
1086:
1084:
1083:
1078:
1077:digital logic
1075:
1074:semiconductor
1071:
1067:
1066:atomic clocks
1063:
1059:
1055:
1050:
1048:
1044:
1040:
1035:
1033:
1029:
1025:
1021:
1017:
1014:was built by
1013:
1009:
1005:
1002:in 1880. The
1001:
997:
988:
975:
966:
959:
942:
938:
934:
929:
922:
917:
910:
908:
906:
901:
897:
893:
889:
881:
879:
877:
873:
869:
861:
859:
857:
853:
849:
844:
837:
835:
833:
829:
825:
821:
817:
809:
807:
804:
800:
792:
790:
776:
772:
764:
762:
759:
755:
750:
746:
734:
727:
718:
711:
694:
692:
680:
672:
670:
668:
665:(328.51
664:
660:
656:
652:
648:
644:
640:
637:to determine
636:
632:
627:
625:
620:
611:
609:
607:
601:
599:
593:
591:
587:
579:
577:
575:
558:
556:
546:
542:
538:
534:
530:
526:
518:
514:
511:
508:
504:
501:
498:
495:
492:
489:
486:
482:
478:
477:
476:
459:
452:
449:
445:
435:
431:
427:
419:
416:
410:
406:
400:
397:
390:
389:
388:
386:
382:
378:
373:
371:
370:watch battery
367:
347:
343:
339:
335:
317:
310:
308:
295:
290:
286:
284:
280:
276:
273:
269:
265:
254:
250:
238:
226:
224:
220:
216:
212:
207:
205:
201:
197:
192:
189:
185:
180:
177:
173:
169:
165:
161:
157:
153:
145:
144:stepper motor
141:
137:
132:
125:
121:
116:
109:
107:
105:
101:
96:
94:
90:
86:
82:
78:
74:
70:
66:
62:
58:
54:
53:Quartz clocks
47:
43:
42:Circuit board
39:
26:
3922:Time capsule
3916:Tempus fugit
3914:
3836:Other fields
3535:
3516:Perdurantism
3438:Calendar era
3390:
3383:
3369:Cuckoo clock
3306:astronomical
3280:
3106:Unit of time
3037:Key concepts
2983:Atomic clock
2978:Quartz clock
2977:
2853:the original
2840:
2836:
2807:
2803:
2782:. Retrieved
2768:
2757:
2746:
2735:. Retrieved
2731:
2721:
2707:
2696:. Retrieved
2684:
2674:
2663:. Retrieved
2656:the original
2643:
2633:
2617:
2598:
2587:. Retrieved
2583:the original
2573:
2557:
2537:. Retrieved
2533:
2524:
2513:. Retrieved
2483:. Retrieved
2479:
2453:
2441:. Retrieved
2426:
2419:
2401:
2381:
2374:
2349:
2345:
2339:
2314:
2310:
2304:
2285:
2276:
2255:the original
2242:
2238:
2228:
2203:
2199:
2193:
2181:
2169:
2142:
2131:. Retrieved
2117:
2106:. Retrieved
2092:
2081:. Retrieved
2067:
2056:. Retrieved
2036:
2025:. Retrieved
2011:
2000:. Retrieved
1986:
1975:. Retrieved
1955:
1936:
1925:. Retrieved
1911:
1900:. Retrieved
1886:
1875:. Retrieved
1861:
1850:. Retrieved
1836:
1825:. Retrieved
1811:
1800:. Retrieved
1790:
1779:. Retrieved
1765:
1754:. Retrieved
1744:
1733:. Retrieved
1719:
1708:. Retrieved
1694:
1683:
1672:. Retrieved
1658:
1647:. Retrieved
1633:
1623:17 September
1621:. Retrieved
1616:
1590:. Retrieved
1580:
1569:. Retrieved
1565:the original
1554:
1519:
1513:
1502:. Retrieved
1482:
1471:. Retrieved
1457:
1446:. Retrieved
1425:
1416:
1378:
1374:
1364:
1353:. Retrieved
1333:
1283:
1224:
1212:
1192:alarm clocks
1185:
1146:
1120:revealed by
1114:wristwatches
1102:pocket watch
1093:
1091:
1087:
1080:
1054:vacuum tubes
1051:
1036:
1000:Pierre Curie
993:
936:
885:
872:crystal oven
868:chronometers
865:
862:Chronometers
845:
841:
813:
798:
796:
768:
741:
676:
631:wristwatches
628:
615:
606:crystal oven
602:
594:
583:
562:
540:
528:
522:
512:
502:
496:
490:
484:
480:
474:
380:
374:
331:
299:
227:
208:
193:
188:Fused quartz
186:fluctuates.
181:
150:Chemically,
149:
97:
56:
52:
51:
3932:Time travel
3910:System time
3817:Time domain
3802:Proper time
3626:use of time
3597:Father Time
3577:Immortality
3567:Ages of Man
3496:Endurantism
3453:Regnal year
3433:Big History
3362:water-based
3261:Solar Hijri
3171:Hexadecimal
3121:Measurement
3083:Chronometry
3069:Measurement
2988:Radio clock
2810:(1): 9–27.
1198:, and time
1126:Ebauches SA
1068:. In 1953,
905:MRI magnets
852:logarithmic
828:synchronize
733:chronograph
574:clock drift
338:tuning fork
184:temperature
110:Explanation
100:solid-state
46:chronograph
3975:Categories
3634:Chronemics
3609:Kalachakra
3521:Presentism
3506:Eternalism
3412:Chronology
3350:mechanical
3301:Main types
3219:Main types
2971:Electronic
2784:2021-10-24
2737:2019-03-03
2698:2021-11-25
2665:2013-12-03
2589:2007-12-06
2539:2019-03-05
2515:2022-01-24
2485:2019-03-03
2443:19 October
2133:2022-01-22
2108:2022-01-21
2083:2019-06-14
2058:2019-06-13
2027:2019-06-13
2002:2021-07-10
1977:2021-10-16
1927:2018-04-25
1902:2018-04-25
1877:2019-06-14
1852:2021-07-26
1827:2018-04-25
1802:2013-04-21
1795:Meier, D.
1781:2012-10-06
1756:2007-09-22
1735:2021-10-10
1710:2019-08-26
1674:2021-10-13
1649:2021-10-12
1592:2010-03-25
1571:2011-11-09
1504:2021-11-28
1473:2022-03-13
1448:2022-03-13
1355:2021-10-26
1303:References
1215:wristwatch
1196:time locks
1130:Basel Fair
1058:Issac Koga
385:cantilever
223:shot noise
211:oscillator
176:phonograph
168:transducer
16:Clock type
3890:Leap year
3807:Spacetime
3681:Yesterday
3582:Dreamtime
3556:Mythology
3443:Deep time
3355:stopwatch
3330:hourglass
3311:astrarium
3241:Gregorian
3234:Lunisolar
3211:Calendars
3201:Time zone
3074:standards
2824:120948178
2693:0362-4331
2277:IEEE UFFC
1546:123587688
1405:0001-4966
1289:amplitude
1161:coin cell
1020:D. W. Dye
892:magnetism
639:longitude
535:/m = 100
453:ρ
420:π
334:resonator
311:Mechanism
294:flip-flop
264:flip-flop
215:amplifier
172:resonator
73:frequency
3950:Category
3698:Time in
3689:Tomorrow
3551:Religion
3491:Duration
3458:Timeline
3392:Timeline
3191:Sidereal
3059:Eternity
2778:Archived
2732:Hodinkee
2626:Archived
2612:, p. 144
2606:Archived
2562:Archived
2509:Archived
2366:51674194
2293:Archived
2290:Marrison
2220:51664900
2127:Archived
2102:Archived
2077:Archived
2049:Archived
2021:Archived
1996:Archived
1968:Archived
1944:Archived
1921:Archived
1896:Archived
1871:Archived
1846:Archived
1821:Archived
1775:Archived
1729:Archived
1704:Archived
1668:Archived
1643:Archived
1495:Archived
1467:Archived
1442:Archived
1413:17927307
1346:Archived
1322:Archived
1233:See also
1219:Q factor
1106:Longines
1070:Longines
965:Junghans
786: Hz
569: Hz
559:Accuracy
553: Hz
407:1.875104
362: Hz
354: Hz
326: Hz
160:resonate
3960:Commons
3883:Related
3797:Instant
3787:Chronon
3769:Physics
3709:Geology
3700:science
3572:Destiny
3417:History
3385:History
3340:sundial
3323:quantum
3266:Chinese
3256:Islamic
3166:Decimal
3161:Chinese
3123:systems
3049:Present
2319:Bibcode
2299:, 1948.
1383:Bibcode
1108:in the
1026:in the
1022:at the
996:Jacques
911:History
876:average
866:Quartz
749:digital
686:⁄
543:= 2634
517:density
515:is its
505:is its
487:) = −1,
483:) cosh(
275:digital
142:of the
104:watches
81:watches
3900:Moment
3895:Memory
3747:period
3335:marine
3318:atomic
3293:Clocks
3251:Hebrew
3246:Julian
3181:Metric
3054:Future
2822:
2691:
2434:
2389:
2364:
2218:
1617:st.com
1544:
1534:
1411:
1403:
1188:timers
1155:(MOS)
1118:Astron
775:AT-cut
745:analog
525:quartz
475:where
342:XY-cut
272:binary
235:
152:quartz
77:clocks
65:quartz
3905:Space
3737:epoch
3727:chron
3685:Today
3654:tempo
3649:Music
3511:Event
3345:watch
3229:Lunar
3224:Solar
3196:Solar
3186:Roman
3176:Hindu
2820:S2CID
2659:(PDF)
2652:(PDF)
2411:(PDF)
2362:S2CID
2216:S2CID
2052:(PDF)
2045:(PDF)
1971:(PDF)
1964:(PDF)
1613:(PDF)
1542:S2CID
1498:(PDF)
1491:(PDF)
1349:(PDF)
1342:(PDF)
1275:Notes
1200:fuzes
1134:Seiko
1122:Seiko
651:Earth
641:(the
619:epoch
346:laser
292:Each
213:, an
3624:and
3587:Kāla
3282:List
3276:Maya
3072:and
3044:Past
3030:Time
2689:ISSN
2635:IEEE
2445:2023
2432:ISBN
2387:ISBN
1625:2023
1532:ISBN
1418:SPL.
1409:PMID
1401:ISSN
1062:NIST
998:and
921:NIST
886:The
754:COSC
747:and
647:West
643:East
624:ages
539:and
531:= 10
140:coil
93:time
79:and
55:and
3742:era
3732:eon
3722:age
3101:TAI
3091:UTC
2885:at
2845:doi
2812:doi
2354:doi
2327:doi
2315:109
2247:doi
2208:doi
1524:doi
1435:144
1433:262
1391:doi
1379:122
1049:.
1041:at
818:or
784:608
781:388
598:ppm
567:768
551:768
537:GPa
360:768
352:768
344:),
324:768
304:768
259:768
244:768
233:768
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3687:–
3683:–
3096:UT
2841:27
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2808:55
2806:.
2776:.
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1028:UK
663:ft
565:32
549:32
545:kg
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358:32
350:32
322:32
302:32
257:32
242:32
237:Hz
231:32
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513:ρ
509:,
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491:l
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