Talk:Pound (mass)/Archive 1

This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

Archive 2

Archive 3

Use of Imperial Pound

The definition of the imperial pound as "obsolete" needs clarification as the unit is still a de facto, if not official, measurment used more frequently than metric in many areas in the United Kingdom. An example is that of measuring the weight of a person in Stones (units of 14ibs) and Pounds and virtually all medical forms completed by patients recognise this practise by allowing the use of either metric or imperial. It is not simply an allowance for older people and feet and inches are used equally for human measurment in everyday situations. Also in boxing arenas the weight of the fighter would never be anounced to the crowd in Kg It would either be in Stones/pounds, or Stones/pounds and Pounds alone where there is likely to be a transatlantic audience for a British boxer.

— Preceding unsigned comment added by Dainamo (talk • contribs) 22:26, 14 March 2004 (UTC)

POV problems

This article had some serious POV problesm, and I think it mostly fixed it. I know it's not perfect so feel free to make stuff look right.

if anyone has some serious griefs with my expressing pounds as weight as the de facto standard, lets discuss itMcKay 08:33, 13 Nov 2004 (UTC)

Hi McKay -- Could you explain more about what you mean? I'm actually fairly happy with the article as it stands. I'm not sure it's accurate to say that layment consider it a unit of weight; laymen actually don't understand the distinction between mass and weight. --Bcrowell 01:54, 15 Nov 2004 (UTC)

How much do you weigh? It's a completely serious question. I doubt that you would express your answer in newtons or say that your mass is 42 kilos. While some (women) won't want to tell you, or will lie. Any answer you get (in the United States), scientist or not, will be expressed in pounds. That's basically it. The Pound as a unit of weight is the de facto standard.

You also make the claim that the layman doesn't know the difference between mass and weight, and while there are a whole lot of people who don't, I would say that most "laymen" do. They teach this stuff in elementary school science classes. My little sister of 10 knows the difference, but she doesn't think that pounds are a unit of mass. When I was in elementary school science classes, I did a report on Saturn. At that time I could tell you how much you weighed on Saturn. (I forget the multiplier now, it might be in the Saturn article. I don't care to check. Mars is 0.6, Moon is 1/6? ) Such a distinction requires knowledge of the difference, or at the very least, a knowledge of the proper understanding of the weight concept (even if the mass concept is unknown). McKay 03:42, 15 Nov 2004 (UTC)

Hmm...I teach college physics, and I wish all my students understood this distinction, coming into my class, from elementary school science. My experience is that almost none of them do. If you ask someone in the U.S. what his weight is, he'll answer in pounds. If you ask someone elsewhere in the world, he'll answer in kilograms. Since the kilogram is undeniably a unit of mass, not weight, I think that demonstrates that the typical person does not understand that there is even a distinction between the two quantities. As a physicist, I think the current state of the article does a fairly good job of discussing how these terms are understood by physicists. What I think would help immensely would be if we could get some contributions from someone who is an engineer in the U.S., and does calculations using the fps system; they are basically the last people in the world who actually calculate things using Newton's laws in the fps system. The NBS article is, to my mind, almost irrelevant, because I know it doesn't represent a clear consensus among physicists, and I suspect it doesn't represent a consensus among U.S. engineers either. A government proclamation can't change the meaning of a word unless it actually matches the way people use the word. I'm still a little unclear about what you meant by POV issues; to me this does not seem to be an issue relating to POV/NPOV, but maybe I'm misunderstanding you. --Bcrowell 19:34, 15 Nov 2004 (UTC)

Just as pressure and stress have different meanings in physics class from what they mean in a psychology class, weight has different meanings in different fields. Sure, in physics and engineering weight means "gravitational force", but in commerce and law it means "mass". When something is sold by weight or by the pound, it's mass and the pound-mass that are being used: it's the amount of the substance that's of interest, not how hard it presses against the ground. Likewise when someone measures body weight to assess health or attractiveness, it's how much matter is in the body that is concerned: being overweight would be just as unhealthy in a low-gravity environment. Body weight is measured in pounds-mass. In fact I can't think a "layman" use of pounds that are pounds-force (except if you consider torque in foot pounds and pressure in pounds per square inch as "layman" uses). It would end a lot of ambiguity if everybody quit using the word weight completely, replacing with "gravitational force" or "mass" as appropriate, but that's not likely to happen. Just as a government can't change the meaning of a word, neither can authors of physics textbooks change the meaning of word outside their field. Indefatigable 23:06, 15 Nov 2004 (UTC)

You see the facts pretty well, Bcrowell--you just appear to have some great difficulty understanding what you know. Yes, kilograms are indeed used for body weight throughout the world, including many hospitals in the United States. And they are indeed the proper SI units for this purpose, as NIST tells us in the external reference on the article page, at [1]

Thus the SI unit of the quantity weight used in this sense is the kilogram (kg) and the verb "to weigh" means "to determine the mass of" or "to have a mass of".

Examples: the child's weight is 23 kg

the briefcase weighs 6 kg

Net wt. 227 g

It is your failure to understand that the pounds also used for this purpose in the United States, when used in either the medical sciences or in sports--the primary reasons we weigh ourselves--are the pounds legally defined as units of mass equal to 0.45359237 kg exactly.

Naturally, if you have been miseducated (as your students likely have been), told that pounds are not units of mass, you have to resort to such a faulty explanation. You imagine a discordance between the use of pounds for weight and the use of kilograms for weight which does not exist. Your major problem is a failure to understand the simple fact that "weight" is an ambiguous word, and it is compounded by your failure to understand the simple fact that pounds are and always have been primarily units of mass, not force. (The pound force is such a recent bastardization that it is uniquely identified by that name. There is no troy pound force, for example. There is no metric pound force.)

The Body Mass Index is also properly named. It is weight in kilograms divided by the square of height in meters. Or you often see it expressed in terms of weight in pounds and height in inches, with a conversion factor added. That conversion factor is always a constant (because of rounding, different people might use different values--but each author only uses one value). The exact number used in the Wikipedia article at the time I write this is 703.07, which is clearly too many digits to be used for pounds force without specifying a location--but one correct to that many digits for the pounds we do use. Nobody ever uses a variable dependent upon latitude and altitude in this context, which it would have to be if your mistaken belief that the pounds used for this purpose in the medical sciences are pounds force were true.

Note also that hospitals which have scales which can measure in either pounds or kilograms (it is often the same scale) do not use different methods to calibrate them for the measurement in pounds from the methods they use to calibrate them for the measurement in kilograms. It is a constant conversion factor between the two, whether it is accomplished by flipping the bar on a balance beam to get a different set of detents for the movable weights, or a constant conversion factor programmed into a microchip.

Note that the pennyweight, like the troy ounce or troy pound, is always a unit of mass. Similarly, the hundredweight (even for those who think hundred is written in digits as "112") and the stone (1/8 of a long hundredweight, still used for body weight in the U.K.), unlike the pounds on which they are based, have not spawned units of force of the same name.

Here's American Society for Testing and Materials, Standard for Metric Practice, E 380-79, ASTM 1979: "3.4.1.2 Considerable confusion exists in the use of the term weight as a quantity to mean either force or mass. In commercial and everyday use, the term weight nearly always means mass; thus, when one speaks of a person's weight, the quantity referred to is mass. . . . When the term is used, it is important to know whether mass or force is intended and to use SI units properly as described in 3.4.1.1, by using kilograms for mass or newtons for force."

BTW, it is also not true that kilograms are "undeniably units of mass, not weight" because the kilogram is usually a unit of mass when it is a unit of weight. But furthermore, changing your last word to "force" wouldn't matter either. The kilogram-force was a quite legitimate unit (also known by another name even, the "kilopond") before the introduction of SI in 1960. There were even coherent systems of units devised with the kilogram force as a base unit of force, with the derived unit of mass the kgf s^2/m, known by several different names such as hyl, TME from a German acronym, metric slug, or mug, because this wonderful invention recurred to several different people bound and determined to show that those using metric units can be every bit as silly as those using English units. We still see far too many vestiges of the use of these obsolete kilograms force--but rarely for anything called "weight" in anybody's book, in any of the various different meanings of this ambiguous word. We see them used for thrust of jet and rocket engines, for tension of bicycle spokes even in the U.S.A., for pressure gauges in "kg/cm²", for torque wrenches in "meter-kilograms", etc. Nobody calls those forces weight. OTOH, the kilograms that are used for body weight of humans, or of other animals as well in fields such as zoology and veterinary medicine, and the kilograms that are used for "net weight" of anything are always units of mass, not force. ("Net weight" is not a physics term.)

The worst of it, however, Bcrowell, is that I suspect that you are not merely a physics teacher, but also a textbook author--of a textbook distributed primarily on the Internet, no less--who has spread his misconceptions in this field far beyond his own classroom.

Gene Nygaard 17:26, 6 Dec 2004 (UTC)

I agree with Gene Nygaard here. The entire section added about force, weight, and mass confuses the issue, and is very poorly written. And of course the pound is only a unit of mass, and has been clearly defined as only a mass by all standards bodies and legislative definitions in all countries for well over a century. I'd recommend that the entire force, weight, and mass section be removed. It's meandering, wrong, and only comes from one person's very confused misconceptions.

In addition, I bristle at any article that says "but physicists/laymen/(insert other confused group) take it to mean something different" and then explain only their own confused, baseless misunderstandings. All such parts should be removed. People don't come to Wikipedia to find out about what some clueless people believe--they come to find out what's actually right. The standards bodies (and even legislatures) that created these definitions well over a century ago clearly understood the difference between mass and weight, and differentiated them unambiguously. Too bad those who teach our kids don't. --Eliasen 08:22, 9 Jan 2005 (UTC)

Sounds fine with me. Elf | Talk 18:48, 9 Jan 2005 (UTC)

Eliasen, you know darned well that pounds are also units of force. Why are you trying to bury your head in the sand?

Most of the information on the pound-force and its definitions and use belongs in the article of that name, but it needs to be mentioned here as well.

It is very important to retain discussions involving the ambiguous word weight. There are far too many people who have gotten the mistaken notion that because a pound is a unit of weight it cannot be a unit of mass (a notion totally contrary to the fact that of all the pounds used throughout history, only one was also used as a unit of force to any significant extent). OTOH, we also have the confused people of Eliasen's class, insisting the opposite: that pounds are not units of force (even though from what I have seem, he or she appears not to understand the ambiguous nature of the word weight so the previously mentioned confusion would seem more probable).

There are also far too many confused science professors in our colleges and universities, and high school teachers and the authors of some of the textbooks they use, filling the heads of students with the nonsense idea that they should measure "their weight" in newtons rather than kilograms or pounds. (And most everybody gets somewhat confused about this—and quite understandably so—failing to understand that the pounds used for this purpose in medicine and sports are units of mass, and that the pounds used for this purpose in many science textbooks, science museum exhibits, and other discussions of "your weight on other planets" are pounds-force.)

There are far too many professors and textbook authors who imagine themselves to be cheesemongers or purveyors of sugar, potatoes, bananas, or whatever, who do not understand that the kilograms used for that purpose—and, most important to this article, the pounds and ounces which appear right alongside them on labels in the United States—are units of mass, not units of force. I guess they must think that talking about the sale of cheese in a physics class can somehow magically change the rules—and they are the proper rules—governing its sale. (Of those who think the pounds are units of force, some think the kilograms are units of force as well, and others imagine some weird statement of measurements of two different quantities on the labels.) Gene Nygaard 13:40, 11 Jan 2005 (UTC)

Let me be clear. The pound is a unit of mass. The pound-force is a unit of force, but that is not the pound. I have never said otherwise. Gene, do you have references by any standards body from any country in the past century that says that the pound is a force? If so, please produce it, otherwise, we should drop the whole force sections, which are in error. I don't want a confused colloquial usage, nor an industry shorthand, but an official standard by a national or international standards body. Say, since 1878 in the UK or 1893 in the U.S.? If so, we can maybe re-open this discussion, but it's been quite clear for a long, long time to all standards bodies (and even legal bodies, except for a minor confusion in Canada's legislative heading of the section of law that defines the pound.) Again, I have placed further references for a wide variety of countries and standards bodies [here]. Do you dispute any of these countries' definitions?

Gene, why do you say that people shouldn't measure their weight in newtons? That is, in fact, totally appropriate. Do you not agree that a newton is a force and that is indeed what is measured by almost all scales? If they're indicating their mass, it should be in kilograms or pounds. Weight is, obviously, not invariant under different accelerational frames, but newtons (or pounds-force) are quite appropriate to measure this varying quantity. I don't know where the confusion lies in your understanding.

I agree that discussion of the pound-force should be in this article. In fact, I believe I put discussion of the pound-force in originally and linked to the pound-force article. It was simple, concise, and sufficient to show the difference. I will reiterate my opinion that any encyclopedia should focus unambiguously on correct usage, not confuse the issue with enumerating the endless permutations of incorrect colloquial usage. That isn't what an article on the pound should be about.

I do believe that if people are confused about the difference between force/weight and mass, then that should be an entirely separate article, and not crammed into the article about the pound, otherwise it will be duplicated among all articles about mass or weight. This article needs cleanup badly. --Eliasen 08:29, 17 Jan 2005 (UTC)

I'll number my comments to correspond to your paragraphs 1-4.

1. Even if standards bodies had defined a "pound-force" that would not mean that pounds are not units of force. Any time you define something as a noun-adjective combination, it is logical and reasonable to expect that the adjective will sometimes be dropped.

However, since standards bodies haven't bothered to define pounds-force, even that is irrelevant. The existence of the pound as a unit of force, whether it is called just a pound, or by the old name "pound-weight" (which at least one old engineering textbook used to mean the geepound or slug, a unit of mass, instead), or the "pound-force" is determined by usage, not by standards bodies who have not acted. Various standards bodies have, of course, recognized the existence of pounds force. See, for example, the footnote 24 in NIST's appendix of conversion factors in SP811, giving a conditional definition of the pound-force. [2]

The main reason I brought that point up was to make sure that those reading this Talk page know what you know. You had written it like you were a dummy who didn't know pounds-force exist; whereas you merely intended to write it like a dummy who didn't know that they are called "pounds."

2. Show us some examples of the use of pounds-force for body weight (keeping in mind that you are the one claiming that pounds are not units of force if they are not identified as such). Better yet, show us all the examples you can find, from all around the world, of people using newtons rather than kilograms for body weight of humans, or of other animals as well in the veterinary or zoological sciences, for that matter.

"[M]easured on almost all scales?" So what happens when you get serious about your weight, and go to the doctor's office or the gym, and weigh yourself on one of those platform-type beam balances? Isn't that a better indication of what you want to measure, than a substitute considered acceptable in many homes because it is cheaply made? Furthermore, those cheap bathroom scales didn't even exist until 1937, well within the lifetime of many people living today. Those spring scales are no more accurate in measuring force than they are in measuring the mass at the location in which they are used.

How about those old scales that used to be seen in public places, where you could put in a penny and get your fortune told, as well as your Honest Weight: No Springs?

"[M]easured on almost all scales?" In a hospital, where they are concerned about not having discrepancies between the scales in different departments, or when someone is transferred to a different hospital, how are those scales calibrated?

Here are some of your "standards bodies" on this point. American Society for Testing and Materials, Standard for Metric Practice, E 380-79, ASTM 1979:

3.4.1.2 Considerable confusion exists in the use of the term weight as a quantity to mean either force or mass. In commercial and everyday use, the term weight nearly always means mass; thus, when one speaks of a person's weight, the quantity referred to is mass.

NIST Guide for the Use of the International System of Units (SI), section 8.3

Thus the SI unit of the quantity weight used in this sense is the kilogram (kg) and the verb "to weigh" means "to determine the mass of" or "to have a mass of."

Examples: the child's weight is 23 kg

Reread this again! You misquoted it. NIST specifically says weight in SI is N. Only in common parlance is it a synonym with kg.

3. You don't even have any clear-cut, universal rules for the use of pounds force (or, for that matter, of English units in general), and not much from any standards organizations in the way of any guidance in their use, so even though I disagree with your philosophy here, it is irrelevant.

4. The confusion most often seen in this regard, the confusion specifically mentioned by many standards organizations, is the confusion you seem to share (based on your "force/weight" and "mass" dichotomy, as well as your discussion about teachers in an earlier comment) with many (other?) science teachers—the failure to understand the simple fact that weight is an ambiguous word, one with several different meanings. Just remember this to help keep it straight in your mind: in the troy system of weights there are no troy-ounces-force and no troy-pounds-force.

You've seen on this talk page, and on edits to the article itself, how this confusion about weight is the root cause of many peoples' beliefs that pounds cannot be units of mass. Even if it is discussed adequately (and relatively permanently, by Wikipedia standards) in another article, a good, strong summary accompanied with a link to that discussion is important in this article.

Gene Nygaard 15:02, 17 Jan 2005 (UTC)

McKay, I hope that little sister runs into better teachers. Soon.

Maybe you could point her to the discussion on this page.

Gene Nygaard 10:43, 8 Dec 2004 (UTC)

...which is a dimensionless constant, defined as 32.17405 lb ft/(lbf s2) and approximately equal to the typical acceleration of gravity on Earth, in ft/s2.

Is the use of the word dimensionless appropriate here?

It could probably be worded better (mea culpa), but it is indeed dimensionless though it is not unitless. See dimensional analysis (a link to that in connection to the quoted statement might be helpful). As that says, a dimension is "the type of unit needed to express it"; for example, feet and meters have the same dimension, something that in this context is usually called "length", often symbolized L. Other dimensions involved here can be called "time" T and "mass" M (other "dimensions" could be chosen, for example force rather than mass, with the same end result). Let's do the dimensional analysis of those units:

unit                   dimension
lb                       M
ft                       L
lbf = 32 lb·ft/s²        M L T^-2
s²                       T²

and then combining them for overall dimensions, lb ft/(lbf s²) = lb ft lbf^-1 s^-2, so the dimensions are:

(M¹)(L¹)(M^-1 L^-1 T⁺²)(T^-2) =

M⁰ L⁰ T⁰ (i.e., dimensionless)

Now do the dimensional analysis of a formula involving this g_c and you will see that the units as they are expressed in the quote above are indeed the correct units. Note the distinction made in the article between this conversion factor used in formulas, something called g_c, and the standard acceleration of gravity, g_n = 32.174 ft/s², which has dimensions of acceleration, or L T^-2. Gene Nygaard 14:16, 27 Jan 2005 (UTC)

You're right, of course. Thank you for the explanation. Having been brought up on SI I'm not used to these conversion numbers. Somehow, it feels a bit less dimensionless than some numbers, though. ;-) Possibly the wording could be improved by changing ...and approximately equal to the typical acceleration... to ...and numerically equal to the typical acceleration.... I was confused by the units on the acceleration and assumed that the units on g_c cancelled to the same.

I added a note about actual use in some applications. I've never seen anyone in my chosen field of study (structural engineering) use pound as a unit of mass. Because of this, a lot of textbooks and references (including the AISC and ACI building codes) use "lb" by itself as a unit of force and slugs as mass, since carrying around g_c is an invitation to disaster. I think that it's useful to tell people that regardless of what standards bodies say lb "should" be, they will run into situations where convention is almost exclusively in the other direction. As an aside, I'd like to know what fields use lb as a unit of mass. I'd been under the impression that civil and mechanical engineering are just about the only scientific fields left that use the imperial system in places where the distinction matters (having to convert between weight and mass). I know that civils usually use lb for force, and have heard anecdotally that mechanical engineers generally do the same.

I don't know if the note should be moved to another place, maybe under the discussion of force vs. mass, but I felt that since it's primarily discussing the labeling issue, I put it where it is.

J. W. Prusi, 03 OCT 2005

Gram-force

RE: Egil 07:55 Mar 26, 2003 (UTC)

Yes, a metric gram is abbreviated to g; this refers to mass. And, there is no force equivalent because one gram of force is a thousanth of a newton. (N= kg*m/s²) Since this is clear and obvious to even people with only a high-school level of scientific knowledge (most people, although perhaps not most wikipedians) and since the majority of the world now use the metric system, why not stick to it instead of getting into petty quarrels over the history of a redundant unit? --220.238.255.204 04:54, 2 August 2005 (UTC)

No, a gram-force is 9.80665 millinewtons, about a hundredth of a newton, not a "thousandth of a newton" or 1 mN. Guess you aren't among those people with a "high-school level of scientific knowledge", right? Gene Nygaard 05:46, 2 August 2005 (UTC)

"Dimensionless" constant can't have dimensions

My correction removing the word "dimensionless" was reverted. I've re-read the talk page on this, and I can see how the word can be defended, but the sentence in is unclear this way, as it still states the number has units. I've made what I hope is a clarifying change.--Jeepien 19:45:27, 2005-08-25 (UTC)

Requested move

Talk:Pound--Pound→Pound (disambiguation)
Pound (weight)→Pound

This is a three-way request, please discuss at Talk:Pound. Gene Nygaard 16:30, 17 November 2005 (UTC)

Pound (unit of mass) and other content

I have been bold, and restructured/reformatted the existing content so that it relates only to the topic of the pound as a unit of mass. In the case of the troy pound, I have limited the content to the pound: it seemed to me that other troy units of mass were better dealt with elsewhere. In the case of the distinction between 'mass' and 'weight' (and 'force') it seemed to me that was better dealt with elsewhere, rather than elaborated on in an article about the name of a specific unit of mass. In the case of the elaboration of the use of 'pound' as a unit of force, it seemed to me that it was better dealt with in the article on pound-force. I've put early pointers to these topics in the article. Fibula 16:47, 6 August 2006 (UTC)

I am highly in support of your moving of the irrelevant and misguided content, which did not serve to underline the proper definition of the pound. It needed to be done, as the content removed was only an attempt to reinforce some individuals' personal misinterpretations of the proper definition of the pound. --Eliasen 21:19, 7 August 2006 (UTC)

What I am trying to do is to have the initial part of the article deal with 'today's pound' and the latter part of the article deal with how we got to where we are today (the history and the pounds that have largely or totally fallen by the wayside over history). Fibula 19:56, 8 August 2006 (UTC)

Pound (weight) redirect

I have changed the Pound (weight) redirect to Pound (mass) from Pound-force. If you look at what links to Pound (weight) almost all the articles are referring to the pound used as a unit of mass (eg amount of stuff) rather than as a unit of force. Some of the articles no doubt are referring to force, but that is the lesser of the two evils. It will take a month of Sundays to go through the articles linking to Pound (weight) individually to make sure they are pointing towards the correct destination. Fibula 16:56, 12 August 2006 (UTC)

So many links are wrong (and need to be corrected anyway) and some are right. The logical redirect is to pound-force, because weight is a special kind of force (not mass). That’s one weak argument for your version of the redirect and one strong argument for mine in my eyes.

The misguiding links are probably to some degree a result of robots applying recent changes in the article title of what is currently pound (mass). They’ll probably change quicker if the result when clicked is unexpected. That would be another argument for a redirect to pound-force. I actually even wouldn’t mind if that article was moved to pound (weight).

I therefore will now revert. Christoph Päper 13:12, 15 August 2006 (UTC)

Actually, weight is a multipurpose term that can mean mass or force due to gravity. But the current arrangement of articles is pretty bad in any case. All we really need is pound (weight), which can describe the meaning of weight (briefly), and the role of the "pound" as a unit of mass or as a unit of force. It could also mention the specific term "pound-force", and voila all the bases are succinctly covered. --Yath 13:59, 15 August 2006 (UTC)

I do not agree, for the reasons set out below under 'Proposed rearrangement' and because I think this should be made User-friendly. In many day-to-day contexts, when people talk about 'weight' they really mean 'amount of stuff' (eg two pounds of cheese) rather than 'gravitational force'. If I were (say) a Frenchman reading an article about a 10-pound cat and I wanted to know what was a 'pound', I would be a little surprised when the (broken) link to 'Pound (weight)' took me to an article about force, when what I expect to discover is what meant by that unit of mass and hope to understand how it equates to the kilograms I use in my day to day lifeFibula 23:41, 17 August 2006 (UTC)

A couple of comments:

Most of the links to pound (weight) are merely remnants of changes made when some misguided soul moved the article now here at "Pound (mass)", which was then at a simple "Pound", to "Pound (weight)", before it was changed to "Pound (mass)". That's one of the reasons why all the links to "pound (weight)" are and should be redirected here. They just haven't been cleaned up yet.
The exact phrasing and word order and punctuation "pound (weight)" is mostly a Wikipedia phenomenon. That reduces the chance of somebody mistakenly using the term which redirects here when pound-force is intended.
Note also that the situation would be different for pound-weight (no parentheses), which arguably should redirect to pound-force. It is now a redlink, and has no articles linking to it. This particular usage was common in many textbooks around the first half of the 20th century. Nonetheless, since I doubt that it is common enough today to warrant it, and also because it might also mean the pound as a unit of mass just as the "pound (weight)" links do, that creating a redirect is desirable. If one is created, I'd say send it to the disambiguation page a "Pound" and let someone come along and figure out which one it should actually be sent to. But since there are no links to that redlink now, it would be better to leave it red and let the people who discover such a redlink determine which pound article it should go to. Gene Nygaard 14:59, 21 September 2006 (UTC)

Pound mass vs weight.

I've been watching this page for a while, partially with disgust. The comment I posted 2 years ago, still doesn't have a response here (Textbooks saying that if you weighed 150 pounds on Earth, you would weigh 55 pounds on mars). I've "fixed" the article to present a NPOV. One that doesn't "favor" the scientists and the standards bodies.

I don't remember why I first came to this page, but I will admit that I have learned quite a bit about this topic since then (including some original research). Also, I have learned a lot about how wikipedia works over the past couple years, so I bring my knowledge to the table.

A comment was made above about laymen not knowing the difference. I have done some 1st class research on this area (blind surveys), and I have found that laymen do know the difference.

Another comment was made above about coming to wikipedia for what is right, not what people think. This is also incorrect. If a (large) group of people think it, it should be represented in Wikipedia. If only what was said here were true, the articles on Relational Database Management System, Relational Model, Relational Database, and virtually every other article with the term "relational" in it would be a lot different, and a lot simpler. Only showing the "techinically correct" side of things is a POV.

All in all, I stand by this edit, and I think that it shows technical correctness, as well as the laymens perspective in the correct light. If you have any further questions, let's work this out.McKay 05:24, 6 August 2006 (UTC)

You raise interesting points. I think the basis of the issue is twofold. First, the pound arose before the difference between weight and mass was understood. And second, that nowadays it is used to mean different things - sometimes as a unit of mass and sometimes as a unit of force.

I too have been told by physics and math professors that the pound is a unit of force, and have even been made to work exercises with "pounds" (units of force) and "pounds-mass", and "slugs" and other odd creatures. I must admit that this now troubles me, since one of the most common real-life usages of the term - in supermarkets - is exclusively as a unit of mass. So as people are being educated, they use pounds as mass, and then are taught pounds as force.

I have to disagree with this. I don't know who was the first one to suggest supermarkets use pound mass, but this is incorrect. Supermarkets, like all other US retails, use pounds force. People may incorrectly think it is mass, but it is weight (force). Weigh one pound of hamburger and you will find it weighs the same as a one pound steel plate used for exercise. Buy a pound of nails, and you get one pound (force) worth of nails. All goods are sold by weight. Many things, including the hamburger, you can see weighed on a scale (which can not technically determine mass as it requires gravity) in front of you.

Another important thing to realize is that the use of mass as a weight and vice versa is a bastardization of the original meaning. These uses arose from people moving from one system (force based) to another (mass based) without attention paid to the difference and meanings and hence is most common in SI countries where Kg is commonly incorrectly used for force (outside of the old archaic derivative kilogram force). I am a Senior Mechanical Engineer for a large multi-national (just one of many I have worked for), and I can say without question (speaking for all our departments) that equating mass and force is not correct and defies the very definition f=ma (which is not ambiguous as suggested here). Math is never ambiguous. PatrickandBrenda 03:47, 11 August 2007 (UTC)

I suspect two possible reasons for this. First, perhaps these professors are familiar with industry practices (please do not laugh) in such areas as aerospace and engine manufacture, where the pound is used generally as a force, unlike most other uses. Or second, and perhaps more likely, is that instructors are keen to deprecate the pound since it is ambiguous, and originated when the difference between weight and mass was not widely understood. And in their zeal to assign every term to its rightful place, they ignore common usage and erroneously say, without reservation, that it is a unit of force.

That is just my speculation, of course. --Yath 15:39, 7 August 2006 (UTC)

I get the impression from this that apparently Yath and I disagree, but maybe I misunderstand who posts where. However, let me say it again, pounds are grandfathered as force. It is for comparison, calibration, and many other means defined by its mass relations to the kg. But the US customary system has and always will be force based. In this system mass is technically, if not realistically, derived from force. Keep in mind this system was developed by people who did fully understand all the principals of the world. So, while possibly illogical, this is the way the system was built. That is why pounds are force as a base unit and pounds mass by derivation. Sorry if this is disturbing, but this is how the US customary system works. If you don't like it, then all that is within your power is to push hard for a conversion to SI. Because this is how the customary system is. Yath, if you intend to dispute me, I would like to know a little about why you consider yourself knowledgeable on this topic? PatrickandBrenda 03:47, 11 August 2007 (UTC)

I recommend that you read weight before proceeding. The meaning of pound as a unit of mass is reported here because that is one of its uses. The measurement of goods in the grocery store, given in pounds, is its mass; the fuel for Navy aircraft, given in pounds, is a unit of mass. In other contexts, "pound" refers to a unit of force.

In this you are completely wrong Yath. While 5 lb of flour in a grocery store, by defintion is both 5 pounds force as well as 5 pounds mass. The use referred to is force. The "legal" basis that you refer to I would like you to quote specifically from law text. The use of pounds force in no way is illegal, as the difference in weight between the bottom of the sea and the top of Everest is inconsequential. I have worked for and with mass manufacturers of materials such as Cargill and Campbell's and I can tell you unequivocally the unit used is force. And to my knowledge they have never been (or at least never successfully) sued for using force. Like all others they use scales (I can't emphasis this enough), which can only determine force. They are never specially calibrated for elevation. They are calibrated at a NIST qualified facility and then sent back to the facility for use. 66.41.157.69 01:41, 12 August 2007 (UTC)

Interesting. I would have expected more from NIST. Politicians I can see misusing mass and force, but NIST... That is honestly is a blight on the scientific community. But even so, commerce is now technical, if not actually, transacted in pounds-mass. I have added a section on "Use in Commerce" to clarify this. Keep in mind this was not true in a historical sense. This was just add to NIST's rules in 1993. But that does mean it is current today. I suggest we also make sure its clear this is a recent change. But I'll leave that to some other day. PatrickandBrenda 18:21, 13 August 2007 (UTC)

It certainly was true in a historical sense. And it is the proper usage. It most certainly is not a recent change. The scales mentioned by 66.41.157.69 are calibrated and tested and certified on the basis of their accuracy in measuring a "reference weight"—an object of known mass and whose force exerted due to gravity will vary with location—in the place in which it is used. Gene Nygaard 16:38, 28 September 2007 (UTC)

It is perfectly obvious that physics professors and others would like to eliminate the use of the term "pound" for mass, but such prescriptive measures are inappropriate for an encyclopedia. We simply report, we do not lead. --Yath 05:48, 11 August 2007 (UTC)

The expert managed encyclopedias you mention (which is mentioned above if you read this whole thing) also says pound is a force. Again, what is you qualification to dispute my knowledge and experience on this Yath? I have told you mine every time and now asked you twice. 66.41.157.69 01:41, 12 August 2007 (UTC)

Thanks yath, Where were you two years ago, when I tried stating that pounds was a unit of force and all I got was resistance. (of the force variety). Yes yath, I guess I do agree with the article as it's presented, mostly by pushing it elsewhere. So, I think that this means that my work here is done, of to Weight. McKay 06:58, 15 August 2006 (UTC)

On the other side of the "zeal" equation, we have wikipedia editors who will gleefully point out that professors are wrong, because the government defines it as a unit of mass. Of course that is just another example of cherry-picking facts, probably for the satisfaction of showing teachers up. --Yath 07:13, 15 August 2006 (UTC)

Pound is a unit of mass. One of the properties of mass (on the earth's surface) is the force of weight. Since this property is pretty useful and easy to derive, one has a scale of force in terms of mass. (physical quantities do not have dimension, it's the scales of units that do: otherwise we could not convert abcoulombs = sqrt(LM) into coulombs (IT)). That 1 lbf/lb = 1 kgf/kg = 1 tonf/ton &c, suggests that there is a scale of force with the dimension M, and that the same unit 'pound' can represent either the mass or force of the same scale. Wendy.krieger 09:45, 19 September 2007 (UTC)

Mass versus weight

I just watched this page, and, man, are issues of mass versus weight popular right about now! There is currently a disagreement over at Talk:Kilogram about whether kilogram should discuss mass v. weight in detail, or link to a really good discussion at weight or elsewhere. Apparently, getting this stuff right is difficult in more than one article. Please participate in the discussion at Talk:Weight#Should mass versus weight get is own article?. Enuja 00:32, 22 August 2007 (UTC)

Divisible by 7?

What is meant by that? The conversion factor is not an integer. —Preceding unsigned comment added by Długosz (talk • contribs) 20:39, 18 September 2007 (UTC)

It means that if you divide the decimal by 7, you get an other exact decimal. The set of numbers that forms exact decimals is an integer system B10. 2 and 5 are units of this, and 7 is a prime. One notes that were the pound defined as what the last UK measurement was (ie 0.453592338 kg), the corresponding grain would be 64.798905428571... mg. By making it a multiple of 7, (ie in the set 7B10), one gets a grain to come out exactly as 64.79891 mg exactly. Wendy.krieger 07:58, 20 September 2007 (UTC)

Metric pound

It might be worth mentioning in this article that in France that I know of (and possibly other countries as well that use the metric system, although I only know of the French example), a "pound" is frequently used to describe 500 grams (or half a kilogram). (In France, one refers to a "livre" in this context).

Its not really a metric pound if its not part of the metric system... it probably has similar origins (livre = libre = lb), but its definately not the same as a pound. Fresheneesz 01:35, 5 December 2005 (UTC)

Given that the 500 g "pound" of many European countries is a metricated "pound", its origin is most certainly in the pound (the actual value being unimportant). Thus, it is a development of the pound, and should be mentioned in this encyclopedic article. --Rfsmit (talk) 21:36, 6 October 2008 (UTC)

On a related note: the section titled Metric pounds should have greater prominence, as their definition and their use are a valuable record of the decline of the older measures.--Rfsmit (talk) 21:36, 6 October 2008 (UTC)

Other pounds

More info:

Pounds that I know of:

avoirdupois pound = 7000 grains (16 oz of 437.5 grains)
troy pound = 5760 grains (12 oz of 480 grains)
Tower pound = 5400 grains (12 oz of 450 grains, I think)
mercantile pound = 7200 grains (15 oz of 480 grains (same as troy))

The last three are all obsolete (nobody uses troy pounds today, though troy ounces are still in use for gold, etc.)

Also, the section "Troy pound" says that a pennyweight is the weight of a penny in Henry II's time, and a fraction of a troy ounce, but in Henry II's time it would have been a Tower ounce, which is somewhat lighter -- the Tower pound was only replaced with the troy pound for monetary weights by Henry VIII (or maybe it was Henry VII; rather later than Henry II, anyway)

I read the linked article, and I've still got some problems with defining pound as mass. It seems like the governments that define a pound as mass do so just because they don't care to differentiate between the mass of an object and the force that gravity exerts on the mass. Maybe they'll come round once we get moon colonies started :-) Governments can make laws saying that dogs are actually cats, but my physics book says,

In the British system, the unit of force is the pound (or pound-force) and the unit of mass is the slug. The unit of acceleration is one foor per second squared, so

1 pound = 4.448221615260 newtons.

Webster's dictionary also specifies the aviordupois pound as a weight. -- Merphant

That it is called weight does not in any way imply that it is "not mass."

Those government officials not only care about the difference--but they are also a whole lot smarter than you are, and they use the definition appropriate for the circumstances.

Why in the world do you suppose governments bother to define a pound in the first place? When we buy and sell goods by "weight," we certainly should not measure some quantity which varies with the strength of the local gravitational field. We do not do so. We have never done so. That pound defined as 0.45359237 kg is the pound legal for commerce in the United States. Just as it should be--until they finally come to their senses and outlaw it, leaving only kilograms and their multiples and submultiples as the legal units for this purpose.

You are wrong. It would be nice to "not measure some quantity which varies with the strength of the local gravitational field", but contrary to your assertion we do do so. We increasingly do so. Perhaps in olden days goods were massed on a balance, but now virtually all (retail, wholesale, etc) goods are weighed on a scale -- that is, measuring the force of gravity acting on the mass of the goods. Unless you believe there is a giant balance beam with a truck-sized mass on it under the highway where the truckers' scales are! No matter what the gov'ts define it as, pounds are used around the world as a force that varies with the local gravitational field.--76.11.113.118 (talk) 06:19, 9 December 2008 (UTC)

When that net weight appears on the label of some U.S. product, the pounds and ounces are, of course, every bit as much units of mass as the grams and kilograms which appear right alongside them. No manufacturer measures two different quantities for this purpose, measuring force for the figure in pounds and mass for the figure in kilograms. No manufacturer puts one "weight" on their products for sale in Barrow, Alaska, and a different "weight" on the same product when it is sold in Honolulu, Hawaii. Nor should they do so.

Note that nowhere in the world are newtons legal units for the sale of goods. Nowhere in the world are kilograms force legal units for the sale of goods. Nowhere in the world are pounds force legal units for the sale of goods.

This is the quite proper and legitimate original meaning of the word "weight," which entered Old English over 1000 years ago meaning the quantity measured with a balance. That quantity is mass, not force. It was used as a measure of how much stuff they had, for the purpose of trade. We still use the very same word, with the very same meaning, for the very same purposes today.

Gene Nygaard 16:14, 6 Dec 2004 (UTC)

There's lots of authoritative citations about the pound always being a mass at:

These link to official legislation, history, and authoritative standards bureaus. The pound is a mass, and always has been (well, for over a century, at least.)

http://futureboy.homeip.net/frinkdocs/faq.html#pound

I should note that my comment for the checkin to the article that read "It's not mass... if you think it is, provide references to any standards body that's defined it as a mass since 1893." were totally wrong. This should read, "It's not force/weight... if you think it is, provide references to any standards body that's defined it as anything but a mass since 1893."

If pounds are mass, then why does every (American) science text book says something like "You would weigh 42 pounds on Mars." It may not be what the standards body uses, but it is what people think. I also remember my physics professor saying that pound is a unit of weight. Now he may not be in concordance with the standards body, but it is common usage, which is what wikipedia should present?McKay 20:03, 24 Aug 2004 (UTC)

Pounds is used as both a mass and as a weight. For example, pounds are defined in kilograms, which is a mass, but as you just mentioned, your weight in lbs on Earth is different than your weight in lbs on Mars. There are two things here - pounds as a mass and pounds as a weight. Since pounds as a mass and pounds as a weight are equal to each other when measured on Earth, and since an object's weight varies with the gravity while its mass remains constant, we can infer that: lbs(weight) = lbs(mass) x g. (Where g is equal to the gravity of the object where the measurement that the weight in pounds was taken and assuming that Earth has a gravity of 1g). So, on earth your weight in pounds would be equal to your mass in pounds. On Mars your weight in lbs would be equal to your mass in lbs multiplied by 0.376 (A person with a mass of 100 lbs would weigh 37.6 lbs on Mars). Jecowa (talk) 18:25, 14 February 2008 (UTC)

lbm should be mentioned, even if its use is not recommendable. It is used, see e.g. http://www.glossary.oilfield.slb.com/Display.cfm?Term=lbm%2Fbbl. -Patrick

Indeed. In that case, we have to mention it; and also say that its use is not recommendable. Likewise, for example, writing "gm" as an abbreviation for gram. -- Tarquin 14:37 Dec 23, 2002 (UTC)

The pound is traditionally a unit of force and weight and is still often used in that sense. The unit was defined before people knew that mass and weight were two differnt things. For anyone who thinks a pound is always a mass, please explain the derived unit of torque, the foot-pound, which is a product of a force and a length. The word pound remains quite ambiguous although, today, it is generally (but, by no means, always) used to mean a mass. Bluelion 19:26 Mar 23, 2003 (UTC)

Pound is for mass, which is also the historic interpretation and definition (see historical weights and measures). Pound (for mass) is abbreviated lb. Pound-force is abbreviated lbf. And there is NO other abbrevitaion for a netric gram but g. Gram is a unit of mass only, always has been. (There used to be a pond unit for gram-force, but this is now totally obsolete). EOD. -- Egil 07:55 Mar 26, 2003 (UTC)

No, pound is for weight historically, and AFAIK still is. Long ago, people weren't aware that mass and weight were different, of course.

I was unaware that anyone thought of it as a mass measure. I edited the page to fix that, but undid the edit after reading the rest of the page and this discussion...someone should sort it out, though. -- User:Tacitus Prime

You could not be more wrong. Pound (lb) historically is both a force and a mass; it always has been and it still is. Drawbar pull of a railroad locomotive, expressed in pounds, is not a mass, for example. There are many others. I notice that the historical weights and measures article you referenced has a lot of empty spaces - needs to be filled in. Bluelion 12:53 Mar 30, 2003 (UTC)

This is historically totally wrong: If anything, pound was at the outset a unit of mass AND a monetary unit. The pound for force must have crept in gradually in the 1700s or thereabouts, but in modern usage it has again become important to separate the two. In modern correct usage (to the degree use of the "pound" unit can be considered "modern") pound as a force is pound-force or lbf. The online EB defines "pound" as unit of avoirdupois weight, equal to 16 ounces, 7,000 grains, or 0.4536 kilograms, and of troy and apothecaries' weight, equal to 12 ounces, 5,760 grains, or 0.37 kg. The Roman ancestor of the modern pound, the libra, is the source of the abbreviation lb. In early England several derivations of the libra vied for general acceptance. -- Egil 05:14 Mar 31, 2003 (UTC)

"If anything, pound was at the outset a unit of mass AND a monetary unit."

Funny, I would have thought it was a weight and a monetary unit. To say it was a mass is revisionist history. If the question is what is 'proper' today, then I have no problem with saying that pound means mass. But saying that, in common usage, that is all it means is a crock. And saying that that is what it has meant historically is also a crock. Before about the middle of the 20th century, I'm quite sure it meant both a force and a mass (yes, I'm that old). And, at that time, I'd bet the prevailing opinion was that it was a force. In recent years there's been quite a campaign by the protectors of all that is good and Holy to get it to mean a mass but, historically, it was both a mass and a force. Unless all the books I have that use the abbreviation lb to represent a force don't exist, and unless the education I got in engine school didn't happen, and unless psi represents a mass per unit area, then the word pound is ambiguous. It means either lbm. or lbf.; we can't be sure unless we know the context. It's a lot like the word billion in that respect. Bluelion 03:19 Apr 1, 2003 (UTC)

FWIW, I remember physics exam questions from school (early '80s) dealing with converting kilograms to pounds on the moon, etc., i.e., taking pounds to be weight, not mass (that was an American school). Also, my old physics 101 text (Physics, Paul Tipler, 1982) defines a pound as a weight/force. Seems to me, to people who really care about the difference, it's a weight; those who say it's a mass probably don't know the difference :)

---

Alright guys, this is silly. Why, when I'm looking up the article describing the unit of weight do I have to choose between pound (force) and pound (mass); neither of which is what I was looking for? This article should be retitled Pound (weight), while "Pound (mass)" becomes a redirect, and the distinction or lack thereof noted in the introductory paragraph. Harumph. --Rfsmit (talk) 21:43, 6 October 2008 (UTC)

Where does lb come from?

Why are pounds called lb in America?--64.121.1.55 20:52, 29 October 2006 (UTC)

They are more correctly abbreviated as lb. From the second line in the Historical origin section:

The word “pound” comes from the Latin word pendere, meaning “to weigh”. The Latin word libra means “scales, balances" and it also describes a Roman unit of mass similar to a pound. This is the origin of the abbreviation “lb” or “℔” for the pound.

MJCdetroit 21:48, 29 October 2006 (UTC)

Just a point of clarification: "lb" isn't just restricted to U.S. usage. However, the "pound sign", #, arose from a quickly written ℔ in the U.S. only. --Rfsmit (talk) 21:52, 6 October 2008 (UTC)

Where does the abbreviation lb come from?

Where does this abbreviation come from? It would be nice if it said so in the article. Brentt 01:00, 29 August 2007 (UTC)

http://en.wiktionary.org/wiki/libra Mannafredo 14:27, 18 October 2007 (UTC)

Also see four sections and a year earlier in this very discussion! --Rfsmit (talk) 21:55, 6 October 2008 (UTC)

Space between digit and abbreviation?

Is 6lb acceptable, or should it be 6 lb? Is there a rule? The Manic Street Preachers don't use spaces. In the section immediately above there is a space before kg and mg. Mannafredo 14:43, 18 October 2007 (UTC)

There's a Wikipedia rule (of course, proper nouns aren't covered by the rule). JЇѦρ 01:59, 9 April 2008 (UTC)

Suggested move

I suggest moving this page to pound-mass. Many references support the use of "pound-force" and "pound-mass" rather than simple "pound" to avoid confusion. The force unit page is already named pound-force. Within certain contexts "pound" by itself is understood to mean mass, while in others, the force meaning is understood. Neither is obviously more correct or valid. Rracecarr 18:44, 2 December 2007 (UTC)

see the section above on Proposed rearrangement. The best suggestion I've seen is to have Pound (weight) as the parent article, which will describe the history of the unit of measure, and in which the other two – far less common – usages are set out. --Rfsmit (talk) 21:58, 6 October 2008 (UTC)

Pounds and ounces

As a non-American this article confuses me. I'm trying to figure out what people use to measure in the US. If you read the article, the word ounce only appears much further down the page and in a context that is unclear as to its relationship with pounds.
In cases like these I rush to http://simple.wikipedia.org/wiki/Pound_(mass) which wasn't much help.
I would much prefer if it were stated in plain English in black and white "1 pound = 16 ounces". Can't we have an infobox on this like they do at Gram?
And by the way, is that how they measure in the US? In Pounds and ounces?
Rfwoolf (talk) 15:22, 13 December 2007 (UTC) Good news, somewhere it "does" mention "An avoirdupois pound is equal to 16 avoirdupois ounces and to exactly 7,000 grains." but I've never ever seen anything on any American site about "4 pounds 5 ounces and oh, 200 grains". I'm going to try and analyse this. Rfwoolf (talk) 15:25, 13 December 2007 (UTC)

♠ You're welcome to add the infobox. Good luck.--THE FOUNDERS INTENT ^TALK 18:24, 13 December 2007 (UTC)

Yes, Americans usually measure in Pounds and Ounces. No one uses grains. For greater precision, it's usually expressed in decimals, like 6.2 oz. Schoop (talk) 19:34, 11 March 2008 (UTC)

Gun enthusiasts ... aren't they a good section of the US population ... use grains. The problem is that the number of ounces to the pound depends on what pound you're talking about. The Troy pound, for example, has twelve. JЇѦρ 01:55, 9 April 2008 (UTC)

Equivalence

I've removed the following recent annonymous addition.

One fluid pint of water weighs exactly one pound at sea-level at a moderately chilly temperature (roughly 50 degrees Farenheit): “The pint’s a pound, the world around.” The volume of one pint is approximately 30 cubic inches or a cubic palm. Hence, with small adjustment, the pint, pound, and palm (PPP) serve as a non-metric example of a set of inter-related units, similar to the milliliter-gram-centimeter, and mega liter-tonne-meter.

Interesting, sure, but this is not the place to invent your own systems of measurement. If you can give us a source for the PPP system, please write us an article. JIMp_talk·cont 17:16, 8 June 2009 (UTC)

Spelling and metrication

See a discussion under the same heading at WT:Manual of Style (dates and numbers). Jc3s5h (talk) 17:30, 9 June 2010 (UTC)

Weight, Mass, and Force

I removed the section "Weight, Mass, and Force" for the following reasons:

It did not cite any sources.
The subject matter had little to do with the article topic.
It was essay-like & POV pushing.
It was overly verbose

I considered leaving it so it could be improved, but on further examination I felt the article was best without it. Djd sd (talk) 05:33, 18 October 2010 (UTC)

Thank you. I agree. The addition of this section was part of some recent major edits of dubious quality (about a month ago). Hans Adler 08:15, 18 October 2010 (UTC)

F. Tendentius

Removing bias is one thing; pushing a theory is another. —Tamfang (talk) 18:10, 10 December 2010 (UTC)

False statement in lead

"[The pound-mass] is not in popular use". Nonsense. The pound-mass is used to sell retail products all over the United States. Although prepackaged items will also have the SI mass stated, retail merchandise that is weighed at the point of purchase is overwhelmingly sold by the pound. Jc3s5h (talk) 19:14, 10 December 2010 (UTC)

But do the scales measure mass (with counterweights) or weight (with springs)? —Tamfang (talk) 20:04, 10 December 2010 (UTC)

The more precise ones use counterweights. Those using springs or the piezoelectric effect are calibrated for standard conditions and would have to be recalibrated if anyone wanted to use them on the Moon. When Sherlock Holmes orders a pound of opium through Amazon, he need not worry whether the seller operates from the top of Mount Everest, from somewhere in the Sahara, of from the bottom of the Mariana Trench: A pound of merchandise is always 0.45359237 kg, regardless of the seller's location. Hans Adler 20:22, 10 December 2010 (UTC)

The mechanism is irrelevant because weights and measures inspectors are sent to the site of the scale and place standards of mass upon the weighing platform. The displayed mass must match the standard within the allowable tolerances. Whether the tolerance is met with a mechanism that compares mases, with strain gauges that are not adjusted for the force of gravity at the scale location, or strain gauges that are adjusted for the scale location, any scale that does not measure the standard masses within tolerance is subject to being placied out of service and/or seized. See the procedures explained in Handbook 112 at the NIST site. Jc3s5h (talk) 20:34, 10 December 2010 (UTC)

Should mass versus weight get its own article?

The discussion referred to by several other talk pages:Is now archived here // FrankB 01:37, 11 December 2010 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Pound (mass)/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Comment(s)

Press [show] to view →

Support: Pound mass and pound force are distinctive and unambiguous measurements. 1 pound force will accelerate 1 pound mass at 32.17405 ft/sec². This is the gravitational constant g_c - acceleration due to gravity at sea level and 45 degrees latitude. Weight and pound force are used interchangeably; weight is a type of pound force. The relationship between weight and mass is:

Weight = (g_l / g_c) pound mass

Where g_l is local acceleration due to gravity

Likewise the relationship between pound force and pound mass is:

pound force = (g_l / g_c) pound mass

Benedict (R.P. Benedict: Fundamentals of Temperature, Pressure and Flow Measurement, Wiley 1984) publishes a formula to calculate g_l if the local constant is not known.

Weight and mass are not the same. An item being weighed on a beam scale will "weigh" the same as a known mass. Both items are subjected to the same gravitational influence. A spring scale calibrated at sea level and 45 degrees latitude using a 1 pound mass will not show the same "weight" for the 1 pound mass at other gravities.

The pound mass and pound force articles should be cleaned up to eliminate the ambiguities. I am happy to help, but as a newbie, I am not certain where to begin.

Brian Dickson 23:51, 25 June 2007 (UTC)

Last edited at 23:51, 25 June 2007 (UTC). Substituted at 21:55, 3 May 2016 (UTC)