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Thermal Gas Mass Flow Meter - Focus on Microfluidic Control Technology

▲ Thermal mass flowmeter features: Range ratio up to 1000:1; small range sensitive; not directly affected by temperature, pressure, direct measurement of gas quality; pressure loss can be ignored; can achieve large-caliber small flow high-precision measurement The price is not much different from the size of the pipeline; the precision can reach 1%; the temperature range can be as wide as -70°C-450°C; it is insensitive to dust and particles.
▲ The principle of thermal mass flow meter: It is a flow meter based on thermal diffusion principle. In layman's terms, the heat source placed in the fluid will lose the heat of the heat source when it passes through it. The greater the mass flow rate of the fluid, the greater the heat loss from the heat source. In this case, the flow rate of the fluid and the heat lost by the heat source should be equal in the ideal case. So we know the size of the heat, we can get the fluid flow.
Specifically for the implementation of thermal gas mass flowmeter (hereinafter referred to as thermal flowmeter), the probe of the thermal flowmeter has two probes, one of which is a reference point for measuring the temperature of the fluid; the other is only Heat source used as a heat source. According to the foregoing, we can have the following formula (3)
P/△T=A+B*(Q)m (3)
Where P - is the power provided by the electronic module for the heating source; ΔT - is the temperature difference between the heating source and the reference point; A, B, - are constants related to the nature of the fluid; m - is related to the nature of the fluid itself The index coefficient; Q—is the mass flow rate of the fluid. From equation (3) we can see that there are two ways to achieve flow measurement: P fixed is the constant power method; △ T fixed is the constant temperature difference method. Usually we use the constant temperature difference method to measure, the characteristics of the constant temperature difference method: a small range of special sensitivity, the reaction speed is fast, the current circulation of products on the market are using this method.
▲ Thermal mass flow meter is easy to use and install. It has plug-in type and pipeline type. Whether it is a plug-in type or a pipeline type, maintenance and operation are extremely simple. When installing, it should be noted that the direction of the fluid should be the same as that indicated by the thermal flow meter.
▲ Disadvantages of thermal mass flowmeter: It is not suitable to install in a large viscosity environment; it is not suitable to install in places where the water content is above 40%.

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