2003-04-05 If these devices determine an objects mass, then shouldn't they properly be called a balance? A scale is used to measure weight (in the sense of force) and not mass.
Common usage of such terms as scales and weight are force related terms because they commonly employed springs. Thus pounds became units of weight (force). Joe Six-pack wasn't interested in location because once he set the scale in his bathroom he didn't care if it was off a little, or didn't think to consider that it was location dependent. With the advent of electronics, it was possible to build a true balance (for home use) that was independent of location and if sub-calibrated in pounds or ounces, would now make the pound/ounce a unit of mass. This back and forth movement of the pound from a unit of mass to force or vice versa, would give headaches to the scientific community, but to Joe Six-pack, neither would he notice or care. But, since the scientific community uses strictly SI, they don't care what the pound is today. The conversions to pounds is strictly for the use of Joe Six-pack, and the accuracy of those conversions is not an issue. John ----- Original Message ----- From: "Jim Elwell" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Cc: "Metric Forum" <[EMAIL PROTECTED]> Sent: Saturday, 2003-04-05 11:45 Subject: [USMA:25434] Re: kitchen scales > At 5 April 2003, 10:32 AM, Gene Mechtly wrote: > >On Sat, 5 Apr 2003, Jim Elwell wrote: > > > > > ... not exceeding 5% error with any of my weights (5 g through 1 kg). > > > >"mass standards" (5 g through 1 kg), are not forces (weights), either in > >a laboratory or in a kitchen. > > > > > ... was never off by more than 1% with any of my calibration weights. > > > >Are your physical standards calibrated in newtons, and if so, at what > >location? > > Gene: > > I am perfectly aware of the difference between weight (force) and mass. > > However, in common usage, e.g., on kitchen and bathroom scales, "weight" is > synonymous with "mass." My calibration weights (masses, if you prefer) are > 5 g, 10 g, 50 g, 100 g, 500 g and 1000 g, and are labeled thusly. My new > scale weighs (masses) in 1 g increments. > > Neither the scale nor my weights are calibrated in newtons. And I, for one, > think we have more important battles to fight than changing the colloquial > usage of "weight" to either "force" or "mass." > > I also have no doubt that some purists on the list will consider this > heresy, but I'll try not to lose any sleep over that. > > > Jim Elwell, CAMS > Electrical Engineer > Industrial manufacturing manager > Salt Lake City, Utah, USA > www.qsicorp.com > >
