How to choose air volume hood and anemometer
The prices of air volume hoods and anemometers vary greatly. Customers often have this question: Can an anemometer replace an air volume hood?
The air volume hood is mainly composed of three parts: the air volume hood, the base, and the PDA. How to choose the air volume hood and anemometer?
The air volume cover is mainly used to collect air volume and collect the wind to the wind speed equalizer on the base. A wind pressure sensor is installed on the uniform wind speed. The sensor reflects the changes in wind speed. The air volume meter adopts the pitot tube principle to automatically detect the wind pressure at multiple points and at multiple points in time. The air volume is then calculated based on the size of the substrate to generate an average Air volume (m3/h). The display of the air volume hood uses a PDA, and the large-screen LCD display is intuitive, and the data of wind speed, air temperature, and air volume can be obtained directly. The recording time interval can be set for continuous parameter recording to facilitate data analysis. The measured and recorded data are recorded on the memory card and will not be lost. The data can be transferred to the PC through the computer's serial port for further application.
Use of anemometer: The flow velocity measurement range of 0 to 100m/s can be divided into three sections: low speed: 0 to 5m/s; medium speed: 5 to 40m/s; high speed: 40 to 100m/s. The thermal probe of the anemometer is used for measurements from 0 to 5m/s; the rotary probe of the anemometer is ideal for measuring flow rates from 5 to 40m/s; and the pitot tube is used to obtain the best results in the high-speed range. . An additional criterion for the correct selection of an anemometer's flow probe is temperature. Typically anemometers' thermal sensors are used at temperatures of approximately +-7˚C. The specially designed anemometer's wheel probe can reach 35˚C. Pitot tubes are used above +35˚C.
Anemometers generally measure at a single point, and the test data accuracy is not high. When the vortex/jet is generated at the tuyere, the wind speed is not very accurate, and it takes several points, or even a dozen points, to measure the average wind speed at one tuyere. If there are several high-efficiency The air supply vent is very troublesome. It takes a lot of time to test and calculate based on the air vent area, but the accuracy is not enough. Therefore, air volume hoods are the most suitable choice for dust-free places with strict requirements.
