MEASUREMENT OF RELATIVE DENSITY OF COMBUSTIBLE GASES

摘要

The relative density of a sample of a supply gas under test is determined by measuring an atmospheric pressure and a pressure differential for the reference gas and the sample gas as each is passed through a small orifice (16) with smooth walls, such as a pore formed in a sapphire jewel. The pressure measurements are made on a time base determined during the reference gas cycle. A microcontroller (15) them computes a relative density for the sample gas based on a known relative density for the reference gas and a ratio of pressure factors for the sample gas and the reference gas in a system operating at in a range from 1 to about 6 psig.