Thermal gas flowmeter is an instrument that detects flow rate by means of heat transfer principle, i.e. according to the heat exchange relationship between fluid in flow and heat source (object heated outside the fluid or heated outside the measuring tube); it mainly measures gas; it mainly divides into two categories: heat distribution and immersion. Type (or insert type).
Characteristics of Thermal Gas Mass Flowmeter
1. The main characteristics of thermal distributed mass flowmeter are as follows: no temperature and pressure compensation is needed for direct measurement of mass flow; non-contact, no moving parts, no blocking parts, low pressure loss and high reliability; low flow rate micro-gas flow can be measured, and Zui low 5 ml/min (standard state); gas medium is required to be dry and clean, without water content and oil. It can be used to measure the flow rate of large and medium pressure, and ensure the flow temperature when using it. The dynamic response is slow and the time constant is about 5 seconds.
2. The main characteristics of immersion thermal mass flowmeter are as follows: direct measurement of mass flow without temperature and pressure compensation; no moving parts, high reliability; suitable for measuring large diameter, non-circular cross-section pipelines, narrow spot space (insertion type); detection as platinum resistance sensor with stainless steel shell, for other dust, Solid particles, oil and water are not sensitive. The plug-in type can be continuously removed, repaired and replaced. It can be used to measure dirty fluid.
II. Application Field of Thermal Gas Mass Flowmeter
Thermal gas mass flowmeter is specially designed for measuring single component gas or mixed gas in a fixed proportion. It has been widely used in petroleum, chemical industry, semiconductor, medical instrument, bioengineering, combustion control, gas distribution, environmental monitoring, precision instrument, scientific research, measurement, food, metallurgy, aerospace and other fields.
Thermal gas mass flowmeter is used for precise measurement and automatic control of gas mass flow. By using standard input and output signals, computer centralized control can be realized. Compared with the traditional flowmeter, it does not need to equip temperature and pressure transmitter, and can directly measure mass flow without temperature and pressure compensation.
When the gas is used as the control variable in the production process (such as combustion, chemical reaction, ventilation and exhaust, product drying, etc.), the quantity of molecule can be controlled by using mass flow controller to measure directly.
If quantitative gas mixing is to be maintained as mixture or ingredient, or chemical reaction process is to be optimized, so far there is no better technology than using mass flow controller. Mass flow controller can continuously adjust and control flow, and accumulated flow can also be obtained through the display device.
Thermal gas mass flowmeter is also a better instrument for detecting the sealing of pipeline system and valves. It directly shows the leakage. Mass flowmeter has the advantages of high performance-price ratio, easy installation and easy operation. The use of mass flowmeter and mass flow controller products is one of the reasonable choices.



Because the sensor of this kind of mass flowmeter is thermal principle, if the gas is not dry gas, it will affect the heat transfer efficiency, thus affecting the output signal and measurement accuracy of the sensor.

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