The thermal flow meter sensor consists of two sensing elements, a speed sensor and a temperature sensor. They automatically compensate and correct for changes in gas temperature. The electric heating part of the instrument heats the speed sensor to a certain fixed value higher than the operating temperature, forming a constant temperature difference between the speed sensor and the sensor measuring the operating temperature. When the temperature difference remains constant, the energy consumed by electric heating, or heat dissipation value, is directly proportional to the mass flow rate of the gas flowing through it.

Thermal gas mass flowmeter is an instrument that uses the principle of thermal diffusion to measure gas flow. 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 gas temperature changes. 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 carries more heat away, and the temperature of sensor RH decreases.

Thermal gas mass flow meter

According to the King's law of thermal effects, there is a definite mathematical relationship between heating power P, temperature difference △ T (TRH-TRMG), and mass flow rate Q. P/△ T=K1+K2 f (Q) K3 K1, K2, K3 are constants related to gas physical properties. The unique temperature difference measurement method of the thermal gas mass flowmeter overcomes the drawback of using the constant temperature difference principle to measure gas flow due to significant zero drift caused by water, oil, and impurities in the gas, which makes it impossible to measure. It can also be used to measure the mass flow rate of wet gas, such as real-time detection of air volume (velocity) in underground gas drainage, air supply, and exhaust systems.

Characteristics of Thermal Gas Mass Flowmeter Products

Convenient installation, simple maintenance, bidirectional detection, anti vibration

Up to 24 point flow measurement

Correction of Output Analog Quantity by Multipoint Nonlinear Curve Correction

Wide range ratio 100:1

Simultaneous detection of flow and temperature, switching display

Large caliber and small flow measurement, capable of leak detection

Encapsulation of sensors using proprietary technology 'dual balanced structure'

Exclusive high humidity and high temperature algorithm, with medium temperature up to 500 ℃

Direct mass flow detection without temperature and pressure compensation

Working principle of thermal gas mass flow meter

Thermal flow meters are flow meters designed based on the principle of thermal diffusion. When a fluid flows through a heating object, the amount of heat lost by the heating object is proportional to the flow rate of the fluid. The sensors of this series of flow meters have two standard level RTDs, one used as a heat source and the other used to measure the temperature of the fluid. When the fluid flows, the temperature difference between the two is linearly related to the flow rate, and then controlled by microelectronics technology, Convert this relationship into a linear output of the measured flow signal.