31:
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At "five nines pure" (99.999%) the gold contained less than 10 parts per million of other elements like silver, aluminum and zirconium, one decimal place purer and hundreds of thousands of dollars more valuable than any gold coinage minted in Vienna or elsewhere,
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We achieved "arguably the purest of all gold" in 1957. Refinery
Officer Leo Hickey and Senior Craftsman Alexander Osborne produced a proof 'plate' of almost six nines - 999.999 parts of gold per thousand - as measured by the Worshipful Company of Goldsmiths in
461:
indicates a system that is available 90% of the time or, as is more commonly described, unavailable 10% of the time – about 72 hours per month. A "five nines" (99.999%) uptime describes a system that is unavailable for at most 26 seconds per month.
84:
However, there are different conventions for representing inexact multiples of 9. For example, a percentage of 99.5% could be expressed as "two nines five" (2N5, or N2.5) or as 2.3 nines, following from the logarithm definition.
387:
of purity for very fine precious metals. Similarly, percentages ending in a 5 have conventional names, traditionally the number of nines, then "five", so 999.5 fine (99.95% pure) is "three nines five", abbreviated 3N5.
494:
For example, the difference between a purity of aluminum of "four nines" and "six nines" is understandable to a scientist, but not necessarily to a politician. (These are 99.99 percent pure and 99.9999 percent
419:, as measured by volume. Thus, a high purity refers to a low amount of other gases, or impurities. Gases of higher purity are in many contexts considered to be of better quality and are usually more expensive.
337:
437:
Intermediate values indicate the digit following the last nine. For example, N4.6 estimates a purity level of 99.996% (four nines followed by a six). An alternative representation uses the
673:
593:
395:, a coin made of gold at 5N (99.999%) purity, stands as the purest gold coin ever minted, anywhere. The purest gold ever achieved was reportedly produced at the
556:
Therefore, in reality, it's virtually impossible to have a 100% chemically pure substance that maintains its purity for an extended period of time.
422:
The purity of a gas is generally expressed as a grade prefixed with the letter N (rather than postfixed), indicating the "number of nines" in the
481:
Technical
Information for Congress: Report to the Subcommittee on Science, Research and Development of the Committee on Science and Astronautics
733:
81:
that appear in a proportion. For example, 90% would be described as "one nine"; 99% as "two nines"; 99.9% as "three nines"; and so forth.
45:
notation for proportions very near to one or, equivalently, percentages very near 100%. Put simply, "nines" are the number of consecutive
400:
430:. For example, a N2.0 gas is 99% (two nines) pure and 1% impurities by volume; a N6.0 gas is 99.9999% (six nines) pure, with 1
527:
For example, good commercial-grade gases for plasma spraying are stated to be at least 99.995% ("four-nines-five" purity).
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such as 0.999 (three nines). Their common uses include grading the purity of materials – especially
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The nines scale is also used in other contexts, such as describing the purity of
92:– though, in the context of purity of materials, 100% is virtually unachievable.
415:. The purity of a gas is an indication of the ratio of it to other gases in its
441:: for example, a gas which is 99.97% pure would be described as N3.5, since log
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if it is 900 fine, or 90% pure. A metal that is 990 fine is then described as
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in 1957, at "almost six nines" (99.9999%) purity, as measured by the
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65: – or measuring the availability of a service.
434:(1 ppm or 1 vpm, volume per million) impurities.
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The exact purity of very fine precious metals such as
277:
331:
609:"The saga of Canada's stolen million-dollar coin"
363:can be of great interest. Based on the system of
332:{\displaystyle \mathrm {nines} =-\log _{10}(1-x)}
453:Nines are used in a similar manner to describe
8:
88:A percentage of 100% would, in theory, have
34:1 troy ounce of four nines fine gold (999.9)
592:: CS1 maint: numeric names: authors list (
27:Logarithmic notation for numbers near 100%
379:and one that is 999 fine is described as
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457:. In this context, a "one nine" (90%)
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539:Bell-Young, Lucy (18 November 2020).
7:
734:List of unusual units of measurement
510:Handbook of Thermal Spray Technology
265:The number of nines of a proportion
674:"Purity, Grades, and Concentration"
507:Davis, Joseph R. (September 2004).
77:are a count of the leftmost digits
640:"The Perth Mint story and history"
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607:Waldman, Ben (31 January 2019).
401:Worshipful Company of Goldsmiths
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1:
53:such as 99% (two nines) or a
484:. 25 April 1969. p. 123
455:computer system availability
90:an infinite number of nines
805:
704:"Definition of five nines"
541:"What Are Pure Chemicals?"
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445:(0.03%) = −3.523.
367:, a metal is said to be
333:
35:
570:"Name that function!"
334:
33:
568:jtw13 (2012-06-04).
383:. Thus, nines are a
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449:System availability
365:millesimal fineness
18:Nines (engineering)
739:Parts-per notation
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515:ASM International
385:logarithmic scale
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16:(Redirected from
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63:industrial gases
55:decimal fraction
41:are an informal
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713:. Retrieved
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618:. Retrieved
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517:. p. 94
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486:. Retrieved
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69:Nomenclature
38:
37:
574:AstroWright
403:of London.
43:logarithmic
759:Metallurgy
753:Categories
685:22 January
645:Perth Mint
579:2024-06-09
466:References
424:percentage
397:Perth Mint
51:percentage
614:Maclean's
391:Canada's
321:−
312:
299:−
219:4 nines 5
185:3.5 nines
168:3 nines 5
744:0.999...
728:See also
715:19 April
651:19 April
620:19 April
588:cite web
550:19 April
521:19 April
488:19 April
369:one nine
353:platinum
247:99.9999%
102:Permille
658:London.
545:ReAgent
417:mixture
253:6 nines
250:999.999
236:5 nines
230:99.999%
213:99.995%
202:4 nines
151:3 nines
134:2 nines
98:Percent
495:pure).
459:uptime
361:silver
233:999.99
216:999.95
196:99.99%
179:99.97%
162:99.95%
117:1 nine
106:Nines
784:Gases
709:PCMag
627:ever.
413:gases
407:Gases
259:N6.0
242:N5.0
225:N4.5
208:N4.0
199:999.9
182:999.7
174:N3.5
165:999.5
157:N3.0
145:99.9%
140:N2.0
123:N1.0
75:nines
49:in a
47:nines
39:Nines
717:2024
687:2017
653:2024
622:2024
594:link
552:2024
523:2024
490:2024
359:and
357:gold
342:Uses
269:is:
73:The
61:and
679:BOC
426:or
371:or
303:log
222:4N5
171:3N5
148:999
131:990
128:99%
114:900
111:90%
755::
706:.
695:^
676:.
665:^
655:.
642:.
624:.
611:.
590:}}
586:{{
572:.
554:.
543:.
525:.
513:.
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443:10
355:,
307:10
256:6N
239:5N
205:4N
191:?
154:3N
137:2N
120:1N
719:.
689:.
596:)
582:.
327:)
324:x
318:1
315:(
296:=
292:s
289:e
286:n
283:i
280:n
267:x
188:?
79:9
20:)
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