Talk:United States customary units

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Contents 1 Township 2 Cable lengths 3 Appropriateness of the term 4 Water freezing temperature 5 Reduction of anti-U.S. bias 6 Mass and weight 7 SQ 8 Links, Chains, Sections, and other survey units. 9 ml or mL 10 Converter Link 11 including barrel 12 mixing units 13 Links 14 slight correction to basis for measurements 15 Naming 16 Old Inch 17 Ease of use of customary units and citations

[edit] Township

• 1 township = 6 sq mi exactly = 36 sections exactly

If a section is 1 sq mi, then a square which is 6 miles wide would be:

6 X 6 = 36 sq mi

--Ed Poor 15:16 Dec 4, 2002 (UTC)

That's right: a township is equal to 36 square miles = 36 sections = a square which is 6 miles long and wide. AxelBoldt 19:52 Dec 4, 2002 (UTC)

[edit] Cable lengths

There are many cable lengths, I've noted the US Navy definition as such, I believe that other cable lengths have also been used in the US (at least the 1/10 nm). -- Egil 12:39 Feb 3, 2003 (UTC)

[edit] Appropriateness of the term

U.S. customary units or its other two spellings occur insufficiently many times under nist.gov to believe it has widespread meaning. In the Web, its occurrence seems largely copied from the Columbia Encyclopedia. --Whir 03:13, 6 Jan 2004 (UTC)

Many US web sites call them "English units". (See this page for a random example). Can any USian tell me if this is a standard usage in the US? -- Heron 08:51, 31 Mar 2004 (UTC)

• Yes, it's standard. English & Metric are the terms used when the distinction needs to be made. The "English system"'s earliest citation in the Merriam-Webster Collegiate Dictionary is 1927, and it is in the most recent edition. An alternative would be the "foot-pound-second system" dating from 1892. "English system" is more common, though the subject doesn't come up much. -- Nunh-huh 08:57, 31 Mar 2004 (UTC)~

Thanks, Nunh-huh. I added a note to this effect. -- Heron 09:16, 31 Mar 2004 (UTC)

I've actually more commonly heard the term standard units used to describe the US units, as in "perhaps we should someday switch from standard units to the metric system." English system is definitely also used though. --Delirium 02:08, May 25, 2004 (UTC)

My question is who "owns" the term "U.S. Customary Units" if anyone. It seems to be an arbitrary distinction to exclude metric units that are used customarily. For example, the liter and milligram are centainly customary units in the U.S. Asprin comes in 84 mg, 325 mg, and 500 mg sizes. There are no equivalent units on the label. Likewise, with pop, water, wine, mouthwash, etc. they are sold and advertised by the liter. I don't know of anyone that thinks or says "I am going to the store to buy a 67.6 oz bottle of pop. My point is that the liter and milligram should be considered U.S. Customary Units based on the word customary. 67.217.42.76 (Larry) 12:23, 12 August 2005

In my opinion, that's a bit of a stretch. Those are two examples where specific industries, which have become dominated by a handful of global companies interested in standardized sizes, using metric, but the rest of the products in the store being sold in other units. Before multinational pharmecutical companies came about in the later half of the Twentieth Century, for example, remedies were produced and consumed locally and measured out in the units listed under "Apothecaries' Weight." It's a similar case with soft drinks, dominated by a handful of multinationals interested in standardized sizes.

Otherwise, people in the US, by custom, will look at a liter and call it a quart. David Iwancio 22:32, 22 September 2005 (UTC)

[edit] Water freezing temperature

Info on freezing temperature of salt water (NOT 0°F)

[edit] Reduction of anti-U.S. bias

I made some NPOV edits today. Metric proponents, please try to avoid terminology and phrasing that reflects your critical opinions about non-metric systems and the relative slowness of metrication in the US. There are many legitimate reasons for resistance to metrication; it's not just ignorance, and it has a lot to do with market forces and the economic costs of conversion. Also consider your own country's role in matters: since international trade is often set up in order to protect national economies by requiring foreign companies to establish a manufacturing presence in the country to which they're selling, there is in these situations little or no export market for goods produced in the US, and thus little incentive for US manufacturers to convert since they don't need to be competitive in foreign markets. This is, of course, changing over time, and it should be noted that metrication is taking place in various industries at a rate roughly proportional to the globalization of those industries (globalization itself being a contentious topic... would you want the US to be metric based so much, if doing so would mean an even greater flow of US-manufactured goods into your country?)

Conversion to and from metric for international commerce and communication may not be easy to remember, but is straightforward. And on the whole, US customary weights and measures are quite usable and AFAIK contain no critical flaws. The only real problem seems to be overlapping terminology and is more a matter of laziness in using the appropriate qualifiers. For example, if one says "ounce" when "fluid ounce" or "troy ounce" is meant, the ambiguity is annoying, but that's hardly a reason to belittle a nation and imply the users of such a system are all ignorant, stubborn fools. The systems are just different, and should be described as matter-of-factly as possible. -- mjb 11:11, 26 Jun 2004 (UTC)

As much as I would love to see the United States switch fully to the metric system, you have a very good point. --70.82.50.67 20:17, 18 June 2006 (UTC)

[edit] Mass and weight

The bits in the article on mass do not really cover the difference between mass and weight: as I undertand it (not being 100% up to speed on English units) there are two ways to handle this neatly in this system, we can use pound to represent mass, in which case the useful unit of weight (or force) is the poundal. Or, you can use pound to represent weight(force) and the slug for mass.

Would need a rewrite...or do we leave as a non technical description and add an article on slugs, poundals, newtons etc elsewhere?

--GPoss 12:24, Jul 23, 2004 (UTC)

Both the poundal and the slug (mass) are attempts to use (what we now call) US units in a "coherent" system of measurement, where "coherent" means 1 * 1 = 1 in terms of derived units (such as 1 kg * 1 m/s^2 = 1 N). However, they don't need to be coherent, working by instead adding a dimensionless constant into your equations (such as 1 lb * 1 ft/s^2 * (1/32.2) = 1 lbf). And before SI was declared to be the "one true metric" there was similar confusion, where some textbooks would use kilograms solely as a unit of force and something called a hyl used for mass.

However, I've never really seen either poundal or slug (mass) used outside of high school or first semester physics courses, with the intent to make equations like "F = m * a" easier to remember (instead of "F = m * a / g"). But as far as US law is concerned, "lb" is specifically a unit of mass, and US engineering classes and professional work use "lb" for mass and "lbf" for force. David Iwancio 23:05, 22 September 2005 (UTC)

[edit] SQ

A roof repairman handed me an estimate that says "25.4 SQ". What the hell the SQ could be? I looked up all possible dictionaries. Mikkalai 19:59, 29 Oct 2004 (UTC)

Maybe "square".

I remember being told that US roofers (tilers?) sometimes use "square" to mean 100 square feet (9.29 m²). "25.4 SQ" could also be intended to mean "(25.4 mm)²", which is one square inch---I doubt the 25.4 just appeared there at random. Or, if you are in the UK, he could have abbreviated squid, which is 1000 £ (you didn't tell in what he estimated). Conclusion: ask the guy. Christoph Päper 16:13, 22 Jun 2005 (UTC)

[edit] Links, Chains, Sections, and other survey units.

Being used for surveying, in the US they're defined by the survey foot instead of the international foot. Therefore, the decimal millimeter values were inexact (a link, for example, is exactly 792,000/3937 mm). So I added a note to the preceding text and pointed out that the SI values given were approximate.

Surveying is also the only place I've seen furlongs used formally and rods used at all. [NIST] tends to classify them as being defined in terms of the survey foot, but there are one or two inconsistencies in this link, so I haven't touched those.

I'm also holding off on touching "acre" for the moment (where 640 acres = 1 square survey mile) for the same reason, but I did remove the line on "section." As with "township," it denotes shape as well as area, describing a square with sides of length of one mile. Instead, I added a note pointing to the Public Land Survey System. David Iwancio 22:05, 22 September 2005 (UTC)

[edit] ml or mL

I know it says "mL" on US soft-drink bottles, but isn't ml the more correct, internationally accepted term? The article mixes these two different ways of "spelling".

From BIPM:

This unit and the symbol l were adopted by the CIPM in 1879 (PV, 1879, 41). The alternative symbol, L, was adopted by the 16th CGPM (1979, Resolution 6) in order to avoid the risk of confusion between the letter l and the number 1. The present definition of the litre is given in Resolution 6 of the 12th CGPM (1964).

As I recall, they also recently reaffirmed that it isn't proper to use a script/italic l as a symbol.

Since both lower-case and capital are equally correct as far as BIPM is concerned, the difference is semantics. The US (and possibly Canada, don't know) tends to use the capital L, Europe seems to prefer the lower-case l or the disallowed script l. Guppy313 23:34, 29 October 2005 (UTC)

The symbol used to be a lower case L but the USA objected (rightly, in my opinion) that it was too easily confused with the digit 'one'. The use of the upper case L was legitimised by the BIPM and both symbols are now acceptable. Here in UK I see mostly lower case L when preceded by prefixes (e.g ml) and upper case when on its own (e.g. 2 L bottles of carbonated drinks). I wish we would just switch to the upper case L and use it consistently. Blaise 22:38, 28 March 2007 (UTC)

[edit] Converter Link

I've added a link to a converter website I put together - www.ConversionStation.com. It converts units of measurement from U.S. to metric to english, and more. I hope the wiki community sees it as an asset rather than spam.

[edit] including barrel

What about including barrel (25 liquid gallons) with the volume measurements? 24.51.79.57 12:07, 8 May 2006 (UTC)

Which "barrel" do you mean? There are many... the oil barrel (42 gal), the beer barrel (31 gal), the liquid barrel (31.5 gal), the dry barrel (26.25 gal)... Marcika 21:56, 7 November 2006 (UTC)

I included the most important ones. - Marcika 21:56, 7 November 2006 (UTC)

[edit] mixing units

the article says "(about 3 millimeters per mile)" which is an ugly mix of units only a small number of people would understand (excluding maybe US) especially since there are 'miles' of different lenght please change to millimetres per km or inches per US mile or something similar

Since this article is about US units, it's pretty clear we're talking about US statute miles. -- Mwalcoff 23:07, 6 July 2006 (UTC)

It’s actually a sensible choice, because the section is about the difference between usual customary and survey units, of which the largest common one is the mile (i.e. both miles). One should give this difference in an independent unit and millimetre does this job well. We could have used micrometres per, for example, yards as well, but mm/mi are probably better imaginable for most readers. Christoph Päper 07:29, 7 July 2006 (UTC)

[edit] Links

I changed the SI equivalents under Units of length for values related to link. Mathematically, if a link is 33/50 feet and a foot is 12 inches and an inch is 2.54 cm, then a link is exactly 20.1168 cm and then a chain is exactly 20.1168 m.

—Ksn 01:16, 19 July 2006 (UTC)

Ah, but a US survey foot is 1200/3937 meter exactly, while an international foot is 0.3048 meter exactly. Since the table is listing survey measure, a link is exactly 792/3937 m, or about 0.2011684023 m. So the values in the table were more precise beforeKsn's "correction". --Gerry Ashton 23:23, 26 July 2006 (UTC)

[edit] slight correction to basis for measurements

The US department of wieghts and measure has the standards by which all of our standard and metric units are measured. Example is something like for a foot they have the item that they will say is exactly one foot long and can be used as a standard for calibrating all other measuring devices. This is the same for all the other measurements. Turns out that we do not just have the Si standards and then convert, we have standards for each seperatly.

See http://physics.nist.gov/Pubs/SP447/contents.html. You will discover that the US has used a meter bar to define all length units from 1893 until 1960, even the US customary length units. All units of mass have been defined in terms of the kilogram no. 20 since 1893. That kilogram is in the custody of NIST. See also Mendenhall Order. It turns out that today, only mass units still depend on physical artifacts, namely, the various standard kilograms in the custody of BIPM and various national standards laboratories. --Gerry Ashton 19:05, 3 November 2006 (UTC)

[edit] Naming

It should be noted that in the United States, the following terms are used (rightly or wrongly) to refer to this system of units:

• U.S. system
• Customary system
• British system
• English system
• Imperial system
• Standard system

Few Americans could illustrate the differences between these systems (if there are applicable differences), and even relatively authoritative resources use the terms interchangeably. This should probably be noted somewhere; I'm not exactly sure how you could cite/source this, though.

This expands upon some previous comments made on this talk page about the ambiguous use of these terms.—Kbolino 00:49, 4 February 2007 (UTC)

[edit] Old Inch

Hang on, this isn't clear:

International measure, agreed in 1959, uses the same definition of the units involved as is used in the UK and other Commonwealth countries. Before that date, those other countries still used separate standards. U.S. survey measure uses an older definition of the units (specified by the former National Bureau of Standards in 1893) which the United States used prior to adopting international measure. Previous to this agreement, the US standard was identical to survey measure.

So does this mean that prior to 1959, the US inch was 25.40005mm? If so, that seems to be an important historical point, and is obfuscated by the article.--Farry 13:52, 4 February 2007 (UTC)

If you look at Mendenhall Order#Reasons for the change you will see the US yard was defined as 3600/3937 meter from 1893 until 1959, so the inch would be 100/3937 meter, or approximately 25.400051 mm. If you think the article should highlight this, go ahead. --Gerry Ashton 19:40, 4 February 2007 (UTC)

[edit] Ease of use of customary units and citations

Some recent edits seem to be on the general theme of the customary units being easier to use than metric units. I have some concerns about the sources used for the recent additions.

One addition is

"The US system of units tends to be based on binary, albeit trinary where that is more convenient, as opposed to the SI system's base 10. While the latter is easier for engineers and bureaucrats in converting units, the former's binary system is centered around units found convenient by regular people, and then the division of those units in half, quarter, eighth, sixteenth, et cetera, producing more chances for a given unit to fall close to the size needed by a user. This benefit has produced a reluctance among its users to adopt the SI metric system, until forced to by authoritarian governments."

The footnote contains a quote: "each Imperial measurement is separated into two packets of easily graspable, one digit numbers, plus a packet of 15 possible fractions." which is taken from an Austrialian Broadcasting Corp. (ABC) web site [1].

Neither the quote, nor the web page as a whole, says anything about SI being forced upon users by an authoritarian government. Also, although the added passage and the ABC web site both generally point out ease-of-use advantages for customary units, the added passage does not seem to be a paraphrase of the ABC web site.

An additional problem is that the ABC web site represents the experience and viewpoint of one person who was interviewed for a radio show, so it is not appropriate to present that viewpoint as the position of Wikipedia.

Another addition is this passage:

An example of the source of resistance can be found in cooking: Units of fluid measure are traditionally set up in a binary fashion, with a quart containing two pints, a pint containing two cups, and a cup divided in to half cups, quarter cups, et cetera. Therefore a single unit of measure is generally close to what is needed in a recipe, whereas in metric one is forced to deal in hundreds of milliliters, which to a US user seems arbitary and complicated. A quarter cup is 59 milliliters, already seeming more trouble, and then if you are doubling the recipe you need either a half cup, or 118 milliliters. Again, the US system feels simpler and more useful for conventional, not-scientific purposes.

This references the web site http://members.aol.com/footrule/usaband.htm. The home page indicates this is a web site of the British Weights and Measures Association. So there are two issues with this source: can we be sure an AOL member web site really is the web site of the BWMA, and how should we phrase the information to indicate it comes from an partisan organization? A further problem is the cited site is mostly about US states that have switched back from metric to customary for state highway construction or building codes, and has nothing to say about cooking measurements. --Gerry Ashton 23:01, 10 March 2007 (UTC)

I have rewritten the first passage mentioned above by adding another source, and making the passage more closely follow the information in the sources. I have eliminated the second passage. --Gerry Ashton 21:51, 11 March 2007 (UTC)