Overview
The thermal gas mass flow meter is designed based on the principle of heat diffusion. The instrument uses the constant temperature difference method to accurately measure the gas. It has the advantages of small size, high degree of digitization, easy installation, and accurate measurement.
The sensor part consists of two reference-level platinum resistance temperature sensors. When the instrument is working, one sensor continuously measures the medium temperature T1; the other sensor self-heats to a temperature higher than the medium temperature T2. It is used to sense the flow rate of the fluid, which is called speed sensing. The temperature T=T2-T1, T2>T1. When the fluid flows through, the gas molecules collide with the sensor and bring the heat of T2 to the temperature of T2. If ΔT is to remain unchanged, the power supply current of T2 must be increased. The faster the gas flows, the more heat it takes away. There is a fixed functional relationship between the gas flow rate and the increased heat. This is the principle of constant temperature difference.
