Industrial ventilation duct flow velocity measurement sensor

Ventilation ducts, referred to as air ducts, are metal or composite pipes used in ventilation and air-conditioning projects in industrial and civil buildings. They are a type of municipal infrastructure designed to circulate air and reduce the concentration of harmful gases. As a common product in our lives, ventilation ducts are now widely used in the market, such as: industrial building ventilation, underground space, safety ventilation, agricultural fields, etc.

The flow in the pipe in the ventilation duct is caused by the pressure difference of the gas at both ends of the pipe. Except for high-temperature gas, it is a constant volume movement. Due to the change in cross-section, the flow rate changes accordingly, and the dynamic pressure and static pressure in the pipe transform into each other. Thus “pipe flow velocity” is often used to mean the flow rate in a closed pipe under pressure . Enclosed ducts are usually round in shape, but can also be square or rectangular.

The other major category of flow is open channel flow, which occurs when a free liquid surface is exposed to atmospheric pressure. For various purposes, it is necessary to measure the flow of fluids flowing under pressure. ISweek Gas Flow Sensor – AFE-01 consists of four platinum thin film resistors with low impedance and small heating zone area. There is a high-impedance resistor on each side of the heater to detect the flow rate and flow direction, and another resistor to detect the temperature of the gas . The two resistors close to the heating element are connected to form a bridge to produce a function of detecting the flow rate and flow direction. output signal. In the absence of flow, the two resistors reach the same heating state. When there is flow, the temperature of one resistor is much lower than the other. The specific resistor temperature becomes lower is determined by the flow direction. The temperature difference can be measured and is determined by the flow rate and flow direction. The flow sensor has a very short heating time and response time because of its small thermal mass.
This way very small changes in flow rate can be detected. To obtain higher flow velocities, the temperature sensor can be connected to a thermostatic anemometer. And because the gas flow sensor AFE-01 is manufactured by a professional European flow manufacturer, it has a very small size, dual flow direction detection, detection of the flow of small mass objects, simple signal processing circuit and calibration, completely fixed mechanical components, and excellent repeatability. It has the characteristics of durability and long-term stability and is suitable for use by medical, instrumentation industries and OEM customers.