Thermal gas mass flow meter threaded type

Overview.

Thermal gas mass flow meter is a new type of instrument used to measure and control the mass flow of gases, which is designed based on the principle of thermal diffusion (heat conduction). The instrument adopts the constant temperature difference method for accurate measurement of gases, and can be applied to monitor the flow of air, oxygen, nitrogen, argon, helium, hydrocarbon gases and other gases in petroleum, chemical, steel, metallurgy, electric power, light industry, medicine, environmental protection and other industrial sectors.

◆Product implementation standard: GB/T20727-2006 (national standard)

◆General standard of flange: GB/T9119-2010 (national standard)

Working principle.

The sensor part of the thermal gas mass flow meter consists of two reference-level platinum resistance temperature sensor, the instrument works, a sensor uninterrupted measurement of the medium temperature T1; the other sensor since heated to a temperature higher than the medium T2, it is used to sense the fluid flow rate, called the speed sensor. The temperature △T = T2 - T1, T2 > T1, when there is fluid flow through, as the gas molecules collide with the sensor and take away the heat of T2, so that the temperature of T2 drops, if you want to keep △T constant, you have to increase the supply current of T2, the faster the gas flow rate, the more heat taken away, the gas flow rate and increased heat there is a fixed function of the relationship, which is the principle of constant temperature difference.

Because the sensor temperature than the medium (ambient) temperature is always automatically constant higher than a certain temperature (30 ~ 50 ℃ or so), so the thermal gas flowmeter from the principle of temperature compensation is not required.

From (1) (2) (3) formula can be seen, the flow rate and working pressure, gas density, working temperature function relationship has been determined. Constant temperature differential thermal gas mass flowmeter is not only not affected by temperature, but also not affected by pressure, thermal gas mass flowmeter is a direct type mass flowmeter, the user does not have to be corrected for pressure and temperature.

Insertion type thermal mass flow meter flow range

Insertion type thermal mass flow meter can be estimated by the corresponding flow rate range 0.56 ~ 56Nm / s, the calculation formula is as follows:

Features.

1. For gas flow measurement without temperature and pressure compensation, easy and accurate measurement, can get the gas mass flow rate or standard volume flow rate.

2. Wide range ratio, up to 100:1 or more, can be used for gas leak detection, especially in large pipe diameter, low flow rate, large changes in the flow range and very small flow measurement has obvious advantages.

3. Good anti-vibration performance, the accuracy is not affected by vibration.

4. Long service life, sensor without moving parts and pressure sensing components, simple installation, easy maintenance.

5. Fast response speed, small pressure loss, good repeatability.

6. Digital design, overall digital circuit measurement, LCD display intuitive and clear, accurate measurement.

7. Equipped with RS485 communication module or HART protocol (optional), with the upper computer can realize centralized management.

面板式流量计厂供电方式不同固定式超声波流量计规定长期连续运行，因此要应用220V交流电，携带式超声波流量计既可以用现场的交流电，也备有内置充电电池，能够连续工作5～10h，大大方便了不同场所暂时性流量计量的必须。

部分作用不同固定式超声波流量计，一般都有4-20mA信号导出等作用，供远传水表显示应用，但其内部只能存储一条管道的参数；携带式超声波流量计只是为了现场查看当时流量和短时间的累计流量，故涡轮流量计批发一般无输出信号作用，但为了方便测量不同管道流量，它具有丰富的存储功能，能够同时存储数不同管道的参数，供随时调成应用。