dasymeter

1. (dated) An instrument for testing the density of gases, consisting of a thin glass globe, which is weighed in the gas or gases, and then in an atmosphere of known density.Examples: "The dasymeter consists of a two-armed lever or balance beam, on one arm of which is a hermetically sealed glass sphere of 3 litres capacity, while the other arm carries a balancing weight. The higher the percentage of carbonic anhydride contained in the gas to be examined, the higher will be its specific gravity, and consequently the greater its weight."; "With the idea that regulation of air supply would secure great economy of fuel, an instrument called a “dasymeter” has been invented to indicate the percentage of carbonic acid in the products of combustion; the weight of a vessel, through which gases are being continually drawn from the chimney of a boiler, is indicated on a scale which shows the percentage of carbonic acid compared with the weight of pure air."; "Spring-balances are in use in numerous early forms of so-called dynamometers, dasymeters, etc., in machines used for testing paper, textile fabrics, wire, etc., as in the apparatus of Hartig-Reusch, Wendler, Martens."dated