The term 'ounce' is also used in other contexts: Historically, a variety of different ounces measuring mass or volume were used in different jurisdictions by different trades and at different times in history.
Historically, in different parts of the world, at different points in time, and for different applications, the ounce (or its translation) has referred to broadly similar but still slightly different standards of mass.
Today, the troy ounce is used only to express the mass of precious metals such as gold, platinum, palladium, rhodium or silver.
Bullion coins are the most common products produced and marketed in troy ounces, but precious metal bars also exist in gram and kilogram (kg) sizes.
For historical measurement of gold, Some countries have redefined their ounces in the metric system.
[7][8] Dutch amendments to the metric system, such as an ons or 100 grams, has been inherited, adopted, and taught in Indonesia beginning in elementary school.
It is defined as the force exerted by a mass of one avoirdupois ounce under standard gravity (at the surface of the earth, its weight).
Ounces are also used to express the "weight", or more accurately the areal density, of a textile fabric in North America, Asia, or the UK, as in "16 oz denim".
[18] The most common unit of measure for the copper thickness on a printed circuit board (PCB) is ounces (oz), as in mass.
It is the resulting thickness when the mass of copper is pressed flat and spread evenly over a one-square-foot area.