Avoirdupois [ ˌævədəˈpɔɪz, ˌævwɑːdjuːˈpwɑː ] is an Anglo-American system of measurement for mass based on one pound , consisting of 16 ounces . It is a traditional commercial weight and is not used for precious metals and medicines. The troy ounce or troy ounce is used here. Although it was officially superseded by the metric system , it is still common in everyday life in the United States , Canada , the United Kingdom and its former colonies.
The word avoirdupois is derived from the old French aveir de peis and, in the 15th century, the Middle English avoir de pois and means goods of weight ( aveir: goods, possessions; avoir: have; peis or pois: weight).
Definition and conversion
The following table shows the conversions of the units of the Avoirdupois system. The pound as the basic unit has been defined as exactly 453.59237 g of the metric system since July 1, 1959. Before 1959, the United Kingdom used the mass of a corresponding weight as the basis; this was determined to be 453.592338 g. In the USA from 1893 to 1959 there was already a definition in the metric system with the Mendenhall Order , according to which the mass of the Avoirdupois pound was exactly 453.5924277 g.
|Commercial weights , Avoirdupois|
|grain||grain||gr.||1 ⁄ 7000 pounds||0.00006479891|
|dram||drachma||dr.||1 ⁄ 16 ounce||0.001771845195312500|
|ounce , coll. lid||ounce||oz.||1 ⁄ 16 pounds||0.028349523125|
|pound||lb||lb., pd., #, lb m .||7000 grain||0.453592370|
|quarter||Quarter penny||¼ hundredweight||11.339809250|
|hundredweight , cental||Hundredweight||cwt.||100 pounds||45.359237|
|volume||ton||T., to.||20 hundredweight||907.18474|
|quarter||Quarter penny||qu., qr. l.||2 stone||12.700586360|
|volume||ton||T., to.||20 hundredweight||1,016.0469088|
- Erich Robens: The Avoirdupois System . In: Balances, Instruments, Manufacturers, History . Springer, Heidelberg 2014, ISBN 978-3-642-36447-1 , p. 61–62 , doi : 10.1007 / 978-3-642-36447-1 (English, limited preview in Google book search).