Thermal gas mass flow meters are instruments that measure gas flow using the principle of thermal diffusion. The sensor consists of two reference-level thermal resistors (RTDs). One is the speed sensor RH, and the other is the temperature sensor RMG that measures the temperature change of the gas. When these two RTDs are placed in the measured gas, the sensor RH is heated and the other sensor RMG is used to sense the temperature of the measured gas. As the gas flow rate increases, the airflow takes away more heat and the temperature of the sensor RH decreases.
4~20mA@HART, RS-485, Bluetooth, Internet of Things