Talk:Units of measurement

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The discussion about the redirection of prefixed metric units to their main unit has been moved to Talk:Units of measurement/Format of articles about units

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[edit] How many basic charged particles in a coulomb?

Why does the number of charged particles (protons, presumably) in a coulomb (6.24150962915265×10E18) cited in the page on the coulomb, [1], differ significantly from the figure used to define the atomic unit of charge in the atomic system of units (1.60217653(14)×10E19) on page [2].

--207.30.168.9 17:16, 11 November 2005 (UTC) Karl Kaiser

Look more closely, it says the elementary charge = 1.60217653(14)×10E-19 C. Note the negative exponent. Invert that number and you will get 6.24150948...E18. That doesn't quite match 6.24150962915265×10E18, presumably because the later is a "newer" value, based on recent measurement conventions. --agr 19:56, 11 November 2005 (UTC)
The unit definitions are expected to change in 2011 anyhow. The CIPM Consultative Committe for Units is hard at work on simultaneously redefining the kilogram, Ampere, kelvin and Mole. This is being done principally in order to obsolete the International Prototype kilogram (which drifts an embarassing 60 micrograms/century), but also to fix the values of the Plank constant h, the elementary charge e, the Boltzman constant kB and Avogadro's number NA (see the Oct 2005 minutes of the CIPM or ampere). The results will include an exact integer number of elementary charges in a coulomb and an exact integer number of (isotopically pure) silicon atoms in a kilogram. In the end most of us will be left wondering what all the fuss was about.LeadSongDog 18:31, 15 August 2007 (UTC)

[edit] are, hectare, decare

See Talk:Units of measurement/Format of articles about units

I notice that somebody recently created the 'decare' article. We now have 3 articles (are, hectare, and decare) that are very similar. The difference is a multiplication factor. A large proportion of the article content is merely duplication or cross referencing. That is just what happened with the other prefixed units (e.g. farad, millifard and microfarad).

It would be easy to convert the 3 articles into a single article. Thoughts?

Incidentally, megahertz is an anomaly in that it is the only multiple of hertz that has its own article. Similarly megawatt is the only multiple of watt that has its own article. Bobblewik 18:38, 12 November 2005 (UTC)

Merge 'em all, I say!
Urhixidur 05:03, 13 November 2005 (UTC)
I think we should go back to individual articles for all of the prefixed units in use.
We could also get rid of those ugly tables in each base unit article, listing combinations that nobody had ever used before, and that nobody will ever use in real life.
  • Many of those tables had all the unit symbols wrong, before I recently fixed some of them: kLm for kilolumens, zKat for zeptokatal, etc.
  • That latter, of course, is an additional big problem. Why are these base unit articles so cluttered up with prefix combinations that nobody has ever used before, and nobody in their right mind would ever use in the real world? We don't need decilumens. We don't need exateslas. We don't need petakatals. We don't need to list centi-, deci-, deka-, and hecto- for anything other than meters and liters and the handful of other cases in which one of those prefixes is used with something else, mostly with non-SI units such as centistokes.
The individual prefixed articles should also be the repository of orders of magnitude information, other than one Orders of Magnitude article for each quantity. None of that 1 E7 W stuff. Gene Nygaard 12:56, 13 November 2005 (UTC)

[edit] Is the distinction between Category:Systems of units and Category:Units of measure

I noticed that Ancient Persian units of measurement is in [Category:Systems of units] and [Category:Units of measure].

Is the distinction between these two categories useful? Bobblewik 17:08, 12 December 2005 (UTC)

[edit] Page name for temperature articles

User:Bobblewik today moved the page from Fahrenheit to Degree Fahrenheit.

To me, that looks funny. I think of Fahrenheit as a scale or system of measuring temperature rather than as a unit like the meter or ounce. I might ask, "What is that (Celsius temperature) in Fahrenheit?" I probably wouldn't say "degrees Fahrenheit" in that situation. -- Mwalcoff 01:22, 29 January 2006 (UTC)

I agree. Strictly speaking, "Degree Fahrenheit" seems like it should basically just say "one 180th of the difference in temperature of boiling water and icewater at standard pressure" rather than discuss the entire temperature system, which is what this page should be doing. ―BenFrantzDale 04:11, 29 January 2006 (UTC)
Also agree, it should be "Fahrenheit". --Yath 05:22, 29 January 2006 (UTC)
I have moved this to the units of measurement page because the solution affects several units of measurement articles.
I think the two options are:
  • Fahrenheit scale - on the basis that it is the name of a scale
  • degree Fahrenheit - on the basis that it is the correct name for the unit.
It would be a shame to have two pages. I happen to think of it as a unit not a scale. I can understand that some people saying that they are thinking of it as a scale.
I would object to it being 'fahrenheit' merely because people (and editors here) often fail to say 'degrees'. That is just colloquial usage and could be mentioned within the article text but should not be a feature of the name.
What do others think? bobblewik 18:06, 31 January 2006 (UTC)
Well, it’s actually degrees on (of?) the Fahrenheit scale. You divide any scale into degrees, even if it’s a clock face—1° used to mean one hour too. A degree of any kind is not a true unit, but many are used much like ones. IMHO the correct place would be Fahrenheit or maybe Fahrenheit scale and there should be redirects from, amongst possibly others, °F and degree Fahrenheit. Christoph Päper 01:30, 1 February 2006 (UTC)
I think I understand some of your point. Somewhere I saw that the unit is degree and the type is Fahrenheit (the sequence: noun-adj) but I can't remember where. I think that is similar to what you said. The same would apply to Celsius. I looked up what the BIPM says at it said "The unit of Celsius temperature is the degree Celsius". They do not distinguish between the two words. I found no official recommendation giving permission to use the noun without the adjective (if that is what they are) but it is widespread colloquial practice. Even the BIPM uses the word 'degree' by itself e.g. "a temperature within one degree of the triple point of nitrogen;".
I still think the page should be about the unit not the scale. Most references to "Fahrenheit" or "Celsius" are references to the unit and not the scale. Clearly this is true for reports of temperature that we hear and see all around us. A small survey indicates it is also true in Wikipedia. I looked at the first ten links to the page and found that 100% were references to the unit, not the scale. bobblewik 10:04, 1 February 2006 (UTC)
I must say I prefer "degree Fahrenheit" over "Fahrenheit" (which ought to be a disambig between the unit/scale and the man). The term is also what is used by the SEG (Society of Exploration Geophysicists), the Unified Code for Units of Measure (Regenstrief Institute for Health Care, Indianapolis), the SAE (Society of Automotive Engineers) and various other organisations.
Urhixidur 12:46, 1 February 2006 (UTC)
The usage I am familiar with is 273 Kelvin = 0 degrees Celsius = 32 degrees Fahrenheit. The temperature article agrees with this usage, by the way. In other words, the measurement 'yy degrees xxx' refers to yy units on the xxx scale, according to the usage which I am familiar with. Now Kelvin is both a unit and an scale. --Ancheta Wis 22:45, 12 February 2006 (UTC) So if the article says 'yy degrees' I would vote for including the scale. But if the article says 2.71 Kelvin (the background temperature of the universe) for example, that is both unit and scale. --Ancheta Wis 22:45, 12 February 2006 (UTC)

A survey of 'What links here' showed it is used as a unit name (100% of the first ten links to the Fahrenheit page, 100% of the first ten links to the Celsius page) not as a scale name. This majority seems consistent with experience outside Wikipedia. So I think the pages should use the unit name, not the scale name. bobblewik 21:29, 2 February 2006 (UTC)

Hmm, seems a little more subtle than that. Perhaps we should have Fahrenheit scale (main article), Fahrenheit (dab or redirect to FS, in which case we keep Fahrenheit (disambiguation)), [Degree Fahrenheit]] -> F S, and of course [[Gabriel Fahrenheit]. We do have, for example Delisle scale, and seem to have this approach where we are not so fmailiar with the terms as to become blinded by usage as to their meaning. Rich Farmbrough. 22:46, 12 February 2006 (UTC)
Voted to keep 'degree' out of the article names; any concern about thinking 'a Fahrenheit' or 'a Celsius' is the name of the unit should be handled by saying it's not in the introduction to each article. But I would support Fahrenheit scale and Celsius scale. -- Perey 01:41, 13 February 2006 (UTC)
^ Thanks Bobblewik for telling me about this vote but I'm afraid I'm voting against your idea. A degree (as far as I'm aware) is not so much a unit as a division. In this case it's a division of temperature scales. It seems to me that Celsius/Fahrenheit are the best names but I also would be happy with Celsius/Fahrenheit scale. Jimp 04:46, 13 February 2006 (UTC)

I don't get the scale thing. There doesn't seem to be a scale article to explain that either (does it have to do with the lack of an absolute point 0?). In my view, Kelvin, Celsius an Fahrenheit are units for the quantity temperature. And degree is a unit for the quantity angle. Degrees Kelvin, Celsius and Fahrenheit don't exist in my vocabulary. I was disappointed to see that this discussion is just about the titles of the articles. I hoped it would be about the whole usage of 'degree'. I'd say the whole misuse of that unit should stop. I don't see any point in adding that to temperature units. Is there a point?

Since I seem to misunderstand something here and the vote is already 'going my way' (for a different reason), I'll refrain from voting unless someone manages to help me understand it. You can also regard this as a tip that the scale/unit thing should be better explanined. I'm no stranger to science (albeit not a scientist), so if I don't get it from Wikipedia a better explanation is obviously needed. 80.126.178.133 08:00, 13 February 2006 (UTC)

Hi, thanks for the message on my talk page; while I think "Fahrenheit" makes more sense, I defer judgement on this matter and therefore will not be voting. Neonumbers 10:20, 13 February 2006 (UTC)

Keep Celsius as it is; merge Fahrenheit into List of strange units of measurement and redirect there :-) MPF 11:48, 14 February 2006 (UTC)

But Fahrenheit is a much more sensible unit for everyday temperatures than Celsius. There are 100 Fahrenheit degrees between "damn cold" and "damn hot", but only 40 or so Celsius degrees. :-) --Carnildo 03:59, 15 February 2006 (UTC)
We europeans are not that sensitive ;-) --FvdP 19:39, 15 February 2006 (UTC)
Interresting point, although not relevant here; can a human feel the difference between, say, 40 F and 41 F? DirkvdM 07:59, 16 February 2006 (UTC)
No; even a difference of 1°C cannot be felt reliably, since 'temperature feel' also depends heavily on wind speed, air humidity, insolation and the observer's muscular activity MPF 16:56, 16 February 2006 (UTC)

My two cents:

  • "Fahrenheit" looks too ambiguous a title, the title should clearly delimit the contents, so "Fahrenheit scale" would be better; "Fahrenheit" should be a disambiguation page, and we can add redirects.
  • "degree Fahrenheit" is not really bad, but given my first argument here above and other people's arguments, I think "Fahrenheit scale" is better. Of course, we should redirect "degree Fahrenheit" to whatever the article goes.
  • the fact that most links come from phrases like "degree Fahrenheit" looks trivial (most mentions of Fahrenheit are bound to be in expressions like "32°F") and irrelevant.
  • For minor older temperature scales named after celebrities, like the Newton scale, the title is already "Xyz scale". Then it would only be consistent to rename "Fahrenheit" as "Fahrenheit scale", etc.

--FvdP 19:41, 15 February 2006 (UTC)

[edit] Vote

Vote will close on 1 March or when total of 20 votes have been cast, whichever is the later. The page names will then be made to reflect the view of the majority.

[edit] The page names should be the unit name i.e. 'degree Fahrenheit' and 'degree Celsius'

  1. bobblewik 21:29, 2 February 2006 (UTC)
  2. Tevildo 22:16, 12 February 2006 (UTC)
  3. Atlant 23:01, 12 February 2006 (UTC) (Well, Degree Fahrenheit and Degree Celsius; Wiki forces the case of that first word)
  4. Urhixidur 23:16, 12 February 2006 (UTC)
  5. With the suggestion that "degrees" rather than degree is preferable (the singular is almost as wrong as not having a unit name), and that 96°F would be better written with the degrees symbol as shown than either of these solutions. --Improv 01:25, 13 February 2006 (UTC)
  6. Same provision as Improv said. This format is very concise, and disambiguates from the person the unit is named for. Rhialto 06:13, 11 November 2006 (UTC)

[edit] The page names should be the scale name i.e. 'Fahrenheit' and 'Celsius'

  1. Kusma (討論) 22:54, 12 February 2006 (UTC)
  2. Mike Dillon 23:14, 12 February 2006 (UTC)
  3. Dpbsmith (talk) 23:21, 12 February 2006 (UTC) Unimportant, that's why we have redirects. But. Use the most common name. Bobblewik's distinction may be technically correct but is not commonly made by laypersons. Article itself can provide whatever explanation is needed.
  4. —Moondyne 00:36, 13 February 2006 (UTC) per dpbsmith
  5. Perey 01:38, 13 February 2006 (UTC)
  6. Ex nihil 01:46, 13 February 2006 (UTC) But preferably 'Fahrenheit scale' or 'Celsius scale' as usage distinguishes between 'degrees Celsius' (a specific temperature, freezing point is 0C) and 'Celsius degrees' ( a range of temperature as in ' the temperature rose 5C degrees) Also Both F & C are adjectives and should have a noun after to describe, unlike Kelvin, which is a unit and a noun.
  7. Carnildo 02:18, 13 February 2006 (UTC) Either "Fahrenheit" or "Fahrenheit scale". "Degree Fahrenheit" is the name of the common division of that scale.
  8. Obviously, for all the above reasons Fawcett5 04:21, 13 February 2006 (UTC)
  9. Jimp 04:46, 13 February 2006 (UTC)[3]
  10. --Yath 07:36, 13 February 2006 (UTC)
  11. Woodstone 08:15, 13 February 2006 (UTC); this name applies both to the degree and the scale; the degree alone does not define the scale. Also it is the most likely term readers are to type when looking for this article;
  12. Akosygin 08:20, 13 February 2006 (UTC) - It has been to my perception that Wikipedia would choose common practice over official naming if the official naming is not common use for a page title to minimize the redirect loads on the server. In which case, most people (IMHO), would just type 'Fahrenheit' or 'Celsius' without the degrees. Since it is more or less acceptable either way, then I believe we should think of what is best for Wikipedia on the technical aspects to reduce work for the servers.
  13. Either would be technically correct, so use the common name for article titles, redirect from others. Stephen Turner (Talk) 09:36, 13 February 2006 (UTC)
  14. I don't really have a strong opinion about this, either way is fine. But I think I prefer to use the scale names if both temperature systems are going to have their own articles. Although the official names of the units include the word "degree", there's more to the history of the temperature scales than the units themselves. (However this makes it harder to spot the fact that there's no such thing as "degrees Kelvin", no matter how many people think so. They're kelvins and that's it.) JIP | Talk 09:56, 13 February 2006 (UTC)
  15. Davidkinnen 15:13, 13 February 2006 (UTC)
  16. Slrubenstein | Talk 16:21, 13 February 2006 (UTC)
  17. Williamborg 02:25, 14 February 2006 (UTC)
  18. Yurik 03:43, 14 February 2006 (UTC)
  19. Wolf ODonnell 10:24, 14 February 2006 (UTC)
  20. For simpler linking MPF 11:41, 14 February 2006 (UTC)
  21. P3d0 13:51, 14 February 2006 (UTC)
  22. Ravedave 19:15, 14 February 2006 (UTC)
  23. --agr 11:59, 17 February 2006 (UTC) As there is no perfect answer, I think the simple linking argument wins. Go to Celsius and click What links here. There are over 1000, most, not all, to just Celsius.
  24. Keep it simple. Thewikipedian 17 February 2006, 18:28 (UTC+1)
  25. I think keep the simplest term, have redirects for the alternatives if required pointing to the main term. - SimonLyall 21:25, 17 February 2006 (UTC)
  26. Simple is best. Though if we had to add a modifier, I'd go with "scale" rather than "degree". -W0lfie 16:06, 27 February 2006 (UTC)
  27. Keep it simple, the editors can always add the extra words. The intro sections handle such formalities as raised by Heron below. FrankB 02:46, 16 March 2006 (UTC)

[edit] The page names should be Fahrenheit scale etc. or similar names mentioning "scale", at least for the Fahrenheit and Celsius scales

  1. --FvdP 19:39, 15 February 2006 (UTC) See my arguments above. Note that I just added this section here because neither of next two sections truly represents my position. I think these three sections should be merged, for fairness sake (even though it seems they are losing anyway...). I've seen "F. scale" arise more often than "F. t. scale" in the discussion above. --FvdP 19:39, 15 February 2006 (UTC).
    • Perhaps we should merge all "scale" categories (as seems to have been the original intent), and remove or replace the overly restrictive "i.e. Fahrenheit or Celsius" (which mislead me) by, say, "i.e. Fahrenheit or Fahrenheit scale or similar, and ditto for Celsius". --FvdP 19:47, 15 February 2006 (UTC)
  • I've already voted for simply Celsius & Fahrenheit however, as I've mentioned above, I'd be happy with Celsius scale & Fahrenheit scale. This is my second preference. Adding temperature in there I don't believe would be necessary: there are no other Celsius or Fahrenheit scales besides the temperature ones. Jimp 16:13, 19 February 2006 (UTC)

[edit] The page names should be Fahrenheit temperature scale, Celsius temperature scale, Kelvin temperature scale, etc.

  1. these names are the most descriptive. The base names Fahrenheit etc. might redirect there, although perhaps they should redirect directly to the scientist as for example Newton does. Another option is that a base names becomes a disambiguation page. Clear article titles give better articles through information organization.MarSch 17:05, 13 February 2006 (UTC)
  2. as above. Avalon 20:02, 14 February 2006 (UTC)

[edit] The page names should be Fahrenheit temperature scale, Celsius temperature scale, kelvin, absolute temperature scale, etc.

  1. There is no such thing as a Celsius or a Fahrenheit, so these words should redirect to the longer versions. Yes, people say "Celsius" when they mean "degree(s) Celsius", but it's only an abbreviation. "Degree(s) Celsius" and "degree(s) Fahrenheit" should not be articles either. We have an article called "cheese", but we don't have one called "piece(s) of cheese". "Kelvin" is different, since the kelvin is the SI unit for the absolute (thermodynamic) temperature scale. --Heron 21:57, 13 February 2006 (UTC)
The naming convention is "use the most common name," not the most technically correct name. Dpbsmith (talk) 10:50, 16 February 2006 (UTC)
  1. I agree with thisBlaise 21:12, 14 February 2006 (UTC)

[edit] Somebody moved 'Square metre' to 'Square Meter'. Please can somebody move it back?

Somebody moved 'Square metre' to 'Square Meter'. I tried but can't move it back. Please can somebody else do it? bobblewik 19:18, 2 March 2006 (UTC)

They did the same to 'Cubic metre'. bobblewik 19:23, 2 March 2006 (UTC)
Done both by copy and redirect. &minusWoodstone 20:10, 2 March 2006 (UTC)
Thanks! bobblewik 20:49, 2 March 2006 (UTC)
It appears to have been corrected to metre again. Only American English uses the meter spelling for the unit. In most of the English speaking world a meter is a measuring device. LeadSongDog 16:42, 15 August 2007 (UTC)

[edit] Online unit converter

I've linked my site to this article. www.conversionstation.com. My intent is to add value to the wiki, not to spam. Some of the areas are still under construction, but if you visit any part of the converter and would like me to add some units, please let me know by posting to mytalk. Thanks. —This unsigned comment is by Zakian49 (talk • contribs) .

[edit] Please watch changes to Metrication

Please can people look at recent changes to Metrication? The edits being made by User:Arfon and the associated IP address do not seem to me to be correct/NPOV. I do not want to get into a revert war. Thanks. bobblewik 21:55, 22 March 2006 (UTC)

[edit] bad sentence

"The United States of America is almost certainly the last to adopt the system but even there it is increasingly being used."

What is this sentence saying? It's hard to decipher.


Just popped in to say the same thing. Is it the last or one of the last. why is it important anyway? Perhaps it would be better to say, "The United States, one of the largest countries, has still not converted to using SI units ... " or something paraphrased to fit the context, or just leave it out. --Candy 13:32, 24 September 2006 (UTC)

[edit] Accuracy and precision

Removed the section below from the article. In my opinion it does not belong in an article on units. It might fit in an article on measuring procedures or reporting of measurements. −Woodstone 08:50, 29 September 2006 (UTC)

Accuracy is a term used to specify the maximum overall error to be expected from a device, such as one that measures a process variable. Accuracy usually is expressed as the degree of inaccuracy and takes several forms:

  • Measured variable, as the accuracy is 1 psig in some pressure measurements. Thus, there is an uncertainty of 1 psig in any value of pressure measured.
  • Percentage of the instrument full-scale (FS) reading. Thus, an accuracy of 0.5% FS in a 10-volt full-scale voltage meter would mean the inaccuracy or uncertainty in any measurement is 0.05 volts.
  • Percentage of instrument span, that is, percentage of the range of the instrument’s measurement capability. Thus, for a device measuring 2% of span for 20-50 psig range of pressure, the accuracy is (0.02)(50-20) = 0.6 psig.
  • Percentage of the actual reading. Thus, for a 5% of reading current meter, we would have an inaccuracy of 1.0 milliamps (ma) for a reading of 20 mA of current flow.

A measurement may be quoted to a certain degree of accuracy.

[edit] Burma?

I have been told in a college class Burma doesn't use metric either.

Nice. But unless you have a documented cite for that, it isn't relevant to wikipedia. Rhialto 11:12, 18 January 2007 (UTC)

[edit] Rating

I've made an initial rating on this article above, perhaps a tad optimistic. Still quite a bit of unsourced content that needs to be corrected to really justify it.LeadSongDog (talk) 09:30, 26 January 2008 (UTC)