NIST and Retail Transactions

If you just bought something that is sold by weight, volume, length, width, height, or some other measurable property, chances are NIST's Office of Weights and Measures has helped to assure that you brought home the amount of product that you thought you bought.

How can you be confident that there indeed is a gallon of milk or a liter of soda in the container you bought at the market? How do you know that the gas pump you used at your local filling station actually delivered the amount and type of gasoline you paid for? Or that there really are 2 cubic feet of mulch in the bag you just brought home from the garden store? Or that the laser scanning checkout system got it right? And what about all of that scanning of prices? How can you be sure that the scanning system records the price that you think you are paying for the item? The same kinds of questions hold for virtually everything that you purchase by weight, length, area, volume, or some other quantitative measure. The more you look around your house, the more things you will find that fall into this category--plywood, paint, garbage bags, rope, wire, land, fabric, plastic wrap, window glass, ceiling tiles, roofing shingles, insulation, carpeting, and far too many more to list. The reason you personally do not have to run around with tape measures, balances, and measuring cups to confirm that you are getting what you pay for is because there is an extensive community of local and state "weights and measures" officials who serve that function. The rock upon which this nationwide network of officials stand is the National Institute of Standards and Technology (NIST), which sponsors the National Conference on Weights and Measures (NCWM). The NCWM is comprised of officials from local and state weights and measures agencies from all over the country whose role is to determine the performance standards of measuring devices (such as the amount of error tolerable in a gas pump or grocer's scale) by which manufacturers, distributors, and vendors determine the cost and/or amounts of products. Not only does NIST's Office of Weights and Measures help the NCWM to develop specific testing procedures and protocols for enforcing the relevant laws, regulations, and codes, but it often is NIST that develops and maintains the ultimate measurement standards to which all others are traced. The accuracy of a set of standard weights that a local inspector might carry with him to a fruit vendor, for example, is ultimately traceable to NIST's standard kilogram made out of an iridium alloy.