sales15@gninstruments.com: how to work of thermal mass flow meter ?

What's the principle of thermal mass flowmeter?

To measure gas flow by measuring the cooling effect of the heating element within the gas flowing through the meter when the. There are within the measurement section of gas through two resistance elements, one of them as the temperature detector, and the other as a heater. A temperature sensing element for detecting the temperature of the gas, varying the current through the heater to maintain a constant temperature difference between the temperature and the measured temperature of the gas. When the gas flow rate increases, the greater the cooling effect, so that a constant temperature shall be kept between RTD current is greater. This heat transfer is proportional to the gas mass flow rate, i.e., current is supplied to the gas mass flow rate has a corresponding function to reflect the flow of gas.

what's the advantages of thermal mass flow meter ?

Thermal mass flowmeter to measure the flow rate (gas 0.02 ~ 2m / s) micro flow; submerged thermal mass flowmeters measure the flow rate of low to medium high (gas 2 ~ 60m / s), plug-in thermal mass flow count more suitable for large diameter. [1]
Thermal mass flowmeter has no moving parts, no shunt heat distributed unimpeded flow meter parts, the pressure loss is very small; hot distributed instruments and immersion of the instrument with a shunt, although in the measurement pipe in the home have Baffles, but the pressure loss is not great.
Thermal mass flow meter performance is relatively reliable. Compared with the derivation of mass flow meters, without temperature sensors, pressure sensors and computing units, etc., only the flow sensor, composed of simple, small probability of failure occurs.
Instrumentation, heat distributed instrumentation proved for H2, N2, O2, CO, NO and so close to the ideal gas of diatomic gas, do not use these special calibration gas, calibration directly on the air for only about 2% difference; for Ar , He and other single-atom gas is then multiplied by the factor 1.4; for other gases in terms of the specific heat capacity is available, but may be slightly larger deviation.
Specific heat capacity of the gas will change with pressure and temperature, but the temperature and pressure used in the vicinity of small changes can be regarded as a constant.

what's the application of thermal flow meter ?

1, Steel Plant, coking plant gas flow measurement;
2, boiler air flow, measuring the amount of secondary air;
3, the chimney flue gas flow measurement;
4, water treatment aeration flow measurement;
5, cement, cigarettes, glass production process gas flow measurement;
6, air flow measurement;
7, natural gas, coal gas, liquefied petroleum gas, flare gas, hydrogen and other gas flow measurement.

Pipe type Thermal Flowmeter