Do you know how gas mass flow meters work？

Application Scenarios

Gas mass flow sensors have a wide range of applications in industry. It can be used to monitor and control gas flow to ensure stable operation in industrial production processes. For example, in the chemical industry, gas mass flow sensor can be used to monitor and control the supply rate of reaction materials to improve production efficiency. In addition, it is widely used in energy, environmental protection, oil and gas, etc. for accurately measuring the mass flow of gases to realize safe and efficient production and operation.

Definition

1. Gas mass flow sensor is a device for measuring the velocity and flow rate of gas flow. It works on the principle of heat conduction.

2. In the sensor, there are two thin, heated resistance wires, often referred to as "hot films". One of the wires is used as a detection resistor, while the other is used to provide a constant heating power. When a gas flows through the sensor, it passes around the resistor wire and captures some of the energy. This causes the temperature of the resistance wire to change.

3. As the gas flow rate increases, the amount of heat absorbed from heating the resistor wire increases. As the gas cools the resistor wire, the temperature of the resistor wire needs to be increased to equalize the heat loss while keeping the heating power constant. Therefore, the change in resistance wire temperature measured by the sensor is proportional to the gas velocity.

4. Through calibration and mathematical modeling, the change in resistance wire temperature can be converted to a numerical output of gas flow rate and flow volume. Sensors typically use digital signals for data transmission to provide accurate measurements.

5. To summarize, gas mass flow sensors estimate gas flow rate and flow rate by measuring the change in resistance wire temperature during gas flow. This principle of operation can be used in a variety of applications such as air flow control, gas metering, etc.

Main Classification

1. Direct Mass Flow Meters

Using the thermodynamic or kinetic properties of the gas to measure the mass flow rate of the gas. Such as calorimetric type, angular momentum type, gyroscopic type and double impeller type. Suitable for measuring small flow rate gas, such as natural gas, metallurgy, mining, petroleum, aviation and other fields.

2. Thermal Gas Mass Flow Meter

Adopting the principle of thermal diffusion, the mass flow rate of gas is calculated by measuring the cooling effect of gas on the heating element. Its sensing element consists of two RTDs, a velocity sensor and a temperature sensor. It is suitable for measuring and controlling gas mass flow rate of new instruments, such as electric power, chemical, metallurgy, environmental protection and other fields.

3. Gas Flow Sensor

Runs by heat exchange, utilizes a thin film, insulated bridge structure designed by silicon chips to measure the flow and direction of air or gas and outputs a corresponding voltage signal. Suitable for measuring the flow and direction of air or gas, such as medical, automotive, food and other gas monitoring and measurement fields.

4. Mass Flow Controller

Integrated flow sensor, control valve and control circuit. It can accurately control the inflow and outflow of process gases. Its sensors are available in differential pressure and thermal types, and its communication methods are analog, digital and various bus protocols. Suitable for precise control of process gas inflow and outflow, such as electronics, semiconductor, photovoltaic and other fields.