For engineering and manufacturing purposes the more important linear gauges are, however, now used, adjusted to some fundamental unit of measure as the inch; although in certain trades, as for wires and flat metals, gauges continue to be used of arbitrary scales and of merely numerical sizes, having no reference to a legal unit of measure; and such are rarely accurate.
The unit of measure is the zar or gez, of which, as in the case of the man, there are several variants.
Diopter (D)-A unit of measure for describing the refractive power of a lens.
The carat is the unit of measure for diamond size, with one carat being equivalent to 200 milligrams, or one-fifth of a gram.
