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A pennyweight (dwt) is a unit of mass equal to 24 grains, 1 ⁄ 20 of a troy ounce, 1 ⁄ 240 of a troy pound, approximately 0.054857 avoirdupois ounce [1] and exactly 1.55517384 grams. [2] It is abbreviated dwt , d standing for denarius – (an ancient Roman coin), and later used as the symbol of an old British penny (see £sd ).
Avoirdupois is a system of mass based on a pound of 16 ounces, while Troy weight is the system of mass where 12 troy ounces equals one troy pound. The symbol g 0 is used to denote standard gravity in order to avoid confusion with the (upright) g symbol for gram.
The pennyweight symbol is dwt. One pennyweight weighs 24 grains, and 20 pennyweights make one troy ounce. [15] Because there were 12 troy ounces in the old troy pound, there would have been 240 pennyweights to the pound (mass) – just as there were 240 pennies in the original pound-sterling.
However, this system of calculation gives only the mass of pure gold contained in an alloy. The term 18-karat gold means that the alloy's mass consists of 75% of gold and 25% of other metals. The quantity of gold by volume in a less-than-24-karat gold alloy differs according to the alloys used.
Such scales are used to make the most accurate of fine measurements, such as in the needs of empirical chemistry. Avoirdupois (/ ˌ æ v ər d ə ˈ p ɔɪ z, ˌ æ v w ɑːr dj uː ˈ p w ɑː /; [1] abbreviated avdp.) [2] is a measurement system of weights that uses pounds and ounces as units. [3] [4] It was first commonly used in the 13th ...
But if it be thought that, either now, or at any future time, the citizens of the United States may be induced to undertake a thorough reformation of their whole system of measures, weights and coins, reducing every branch to the same decimal ratio already established in their coins, and thus bringing the calculation of the principal affairs of ...
Conversion and its related terms yield and selectivity are important terms in chemical reaction engineering.They are described as ratios of how much of a reactant has reacted (X — conversion, normally between zero and one), how much of a desired product was formed (Y — yield, normally also between zero and one) and how much desired product was formed in ratio to the undesired product(s) (S ...
Mass; system unit unit-code symbol or abbrev. notes sample default conversion combinations SI: kilogram: kg kg 1.0 kg (2.2 lb) kg lb. kg lb st; kg st. kg st lb; gram: g g