This is known as the calorific value of the gas. Junker's Gas Calorimeter used in Petroleum Industries/Laboratory, Coke Oven Batteries, Thermal Power House Cement Industries, Gas Companies, Steel Plants and Fertilizer Industries.  Junker's principal of Burning of known Volume of Gas under maximum efficient method of heat transferring conditions and imparting the heat to a stealing flowing water and finding out the amount of heat transferred. The equipment consists of calorimeter with burner on a tripod stand, Gas Flow meter (non-recording type) pressure Governor and Digital temperature indicator.