Troy weight troy relates to a dialect word troi (balance). Then troy weight is a style of weighing, like auncel or bismar weights, or other kindred methods. The troy weight then refers to weighing of small precious or potent goods, such as bullion and medicines. Troy ounces are still often used in precious metal markets in countries that otherwise use International System of Units (SI), except in East Asia. The People's Bank of China, in particular, which has never historically used troy measurements, has begun issuing Gold Pandas minted according to SI weights. The troy pound is 5 760 grains (≈ 373.24
Heavy metals cooling towers. Depending on their intended use as fertilisers or biocides, agrochemicals may contain heavy metals such as chromium, cobalt, nickel, copper, zinc, arsenic, cadmium, mercury, or lead. Selected heavy metals are used as catalysts in fuel processing (rhenium, for example), synthetic rubber and fibre production (bismuth), emission control devices (palladium), and in self-cleaning ovens (where cerium(IV) oxide in the walls of such ovens helps oxidise carbon-based cooking residues). In soap chemistry, heavy metals form insoluble soaps that are used in lubricating greases, paint dryers, and fungicides (apart from lithium, the alkali metals and the ammonium ion form soluble soaps).