ABSTRACT
Positive displacement gas meters measure by internally passing isolated volumes of gas that successively fill and empty compartments with a fixed quantity of gas. The filling and emptying process is controlled by suitable valving and is translated into rotary motion to operate a calibrated register or index That indicates die total volume of gas passed through the meter. Applications of the liquid sealed drum meter today include laboratory work, appliance testing, pilot plant measurements, and as a calibration standard for other meter types. The measurement section consists of four chambers formed by the volumes between the diaphragms and the center partition and between the diaphragms and the meter casing. The rating of small diaphragm meters is usually specified in cubic feet per hour of 0,6 specific gravity gas which result in a pressure drop of 0.5 in.
