SCM20FD is a high-precision series flowmeter/controller,its measurement error is only ±0.5% of full scale, the excellent accuracy of this series comes from the unique sensor probe, this sealed probe consists of two sensing elements – speed sensor and temperature sensor , can automatically correct temperature and pressure changes impact of . The meter circuit heats the speed sensor to a constant value above the gas/liquid temperature and then measures the cooling effect of the gas flow. The flow rate is calculated by measuring the electrical power consumed to maintain a constant temperature difference proportional to the gas mass flow rate. Both sensors are standard grade platinum resistance temperature detectors (RTDs) hermetically sealed into 316 stainless steel packaging.