Thermal Gas Mass Flow Meter
The thermal gas mass flow meter is designed based on the principle of heat diffusion,and the meter uses the constant temperature difference method to accurately measurethe gas. The advantages is small size, high degree of digitization, convenient installationand accurate measurement
The sensor temperature part sensors is composed when the of two instrumentis
reference-level working one platinum sensor resistance continuously measures the medium temperature T1; the other sensor is self-heated to be higher than the medium temperature T2, which is used to sense the fluid flow rate, called velocity sensor.
Product Details
Parameters:
Thermal gas mass flow meter has the following technical advantages:
Convenient and accurate measurement. The mass flow rate or standard volume flowrate of the gas can be obtained wide range ratio, can measure gas with flow rate as high as 100Nm/s and as low as 0.1Nm/s, can be used for gas leak detection.
Good anti-seismic performance and long service life. The sensor has no moving partsand pressure sensing parts, and is not affected by vibration on measurement accuracy.
Easy installation and maintenance. When site conditions permit, non-stop productioninstallation and maintenance can be realized. (requires special customization
Digital design. Overall digital convenient maintenance.
circuit measurement accurate and Using RS-485 communication, or HART communication, can realize factory automationand integration.
Applications :
Compressed air or gas measurement and leakage detection: pneumatic systems in factories, gas production metering of air compressors.
Combustion Control: Gas/combustion air flow control for boilers and kilns.
Environmental Monitoring: Flue gas and exhaust gas emission monitoring (CEMS).
New Energy and Chemical Industry: Flow measurement of biogas, hydrogen, coalbed methane, and reaction gases.
Semiconductor and Pharmaceutical Industry: Flow measurement of high-purity process gases and fume hoods/exhaust ducts (VAV control).
Scientific Research and Experiments: Occasions requiring precise gas mass flow.
Usage Restrictions :
Sensitive to gas composition changes: The instrument is calibrated for specific gases (or mixed gases with fixed components). If the gas composition changes significantly, it must be recalibrated; otherwise, large errors will occur. Because its principle is based on the thermal conductivity coefficient and specific heat capacity of the gas。
Not suitable for dirty, liquid-containing, or wet-saturated gases: Dust, oil, and droplets will adhere to the probe surface, forming an “insulation layer”, which seriously affects the measurement accuracy and may even damage the sensor.
Requirements for installation: It is necessary to ensure a stable flow field at the measurement point. Usually, a straight pipe section before (10D – 20D) and a straight pipe section after (5D) are required, especially when the pipe diameter is large or the flow field is complex.
Lower range limit: Although it can measure extremely low flow velocities, when the flow velocity drops to a certain level (the heat is mainly carried away by gas conduction rather than convection), the measurement becomes difficult.
Model Selection Points:
Gas medium and components: Please inform us the detailed gas name and contents .This is the basis for model selection .
Flow range: Specify the minimum, normal, and maximum flow rates (under working conditions, Nm³/h or kg/h).
Process conditions: Pipe size, gas temperature, pressure, humidity, and cleanliness.
Accuracy requirements: In general working conditions, the accuracy is between ±1.0% ~ ±2.5% FS or the read value.
Output and communication requirements: 4 – 20mA, pulse, and field buses such as HART, MODBUS, PROFIBUS, etc.
Explosion-proof and protection levels: Select according to the installation area (hazardous area, outdoors, etc.)
