1. introduction

　　Thermal gas mass flow meter is designed on the basis of thermal dispersion, and adopts method of constant differential temperature to measuring gas flow. It has advantages of small size, easy installation, high reliability and high accuracy, etc. The meter contains two platinum resistance temperature sensors. The thermal principle operates by monitoring the cooling effect of a gas stream as it passes over a heated sensor. Gas flowing through the sensing
section passes over two sensors one of which is used conventionally as a temperature sensor, whilst the other is used as a heater.

　　The temperature sensor monitors the actual process values whilst the heater is maintained ata constant differential temperature above this by varying the power consumed by the sensor. The greater the gas velocity, the greater the cooling effect and power required to maintain the differential temperature. The
measured heater power is therefore a measure of the gas mass flow rate.

　　Due to the sensor temperature is always 30℃ higher than the medium temperature (environment temperature), and the meter adopts method of constant differential temperature, therefore the meter do not need to do temperature and pressure compensation in principle.

2. Feature

　　2.1 Measuring the mass flow or volume flow of gas.

　　2.2 Do not need to do temperature and pressure compensation in principle with accuratemeasurement and easy operation.

　　2.3 Wide range: 0.5Nm/s～100Nm/s for gas. The meter also can be used for gas leakdetection

　　2.4 Good vibration resistance and long service life. No moving parts and pressure sensorin transducer, no vibration

　　influence on the measurement accuracy.Easy installation and maintenance. If the conditions on site are permissible, the metercan achieve a hot-tapped installation and maintenance. (Special order ofcustom-made)

　　2.5 Digital design, high accuracy and stability

　　2.6 Configuring with RS485 or HART interface to realize factory automation and integration

3. Parameters