The development and characteristics of anemometer

Invented in the 1920s, anemometer requires a thin wire to be placed in a fluid. The current heats the wire, making it hotter than the fluid, so the wire is called a "wire." The length is generally in the range of 0.5 ~ 2 mm, the diameter is in the range of 1 ~ 10 micron, the material is platinum, tungsten or platinum rhodium alloy. If the metal wire is replaced by a very thin metal film (thickness is less than 0.1 micron), it is called the hot film anemometer. Its function is similar to that of the hot wire, but it is mostly used to measure liquid velocity. In addition to the ordinary single-wire type, it can also be combined double-wire type or three-wire type, which can be used to measure the velocity component in all directions. After amplification, compensation and digitization, the electrical signals output from the line can be input into the computer, which can improve the measurement accuracy, automatically complete the data post-processing process, and expand the velocity measurement function, such as simultaneously completing the measurement of instantaneous value and time mean, combined velocity and partial velocity, turbulivity and other turbulence parameters.







Hot bulb anemometer





Anemometer belongs to the metrological instrument of safety protection and environmental monitoring, which is a mandatory metrological instrument stipulated by China's measurement law. In addition to the factory sales need to be equipped with the appropriate calibration report, also need to according to JJG (construction), 0001-1992 "hot bulb anemometer verification regulation requirements regularly every year to the national air conditioning construction quality supervision and inspection center or the China construction science research institute in energy and environmental testing center regular calibration, and according to its legal calibration certificate issued by the instrument to adjust all aspects in order to obtain the best working state.

Main Features:

1. Small volume and small flow field interference.

2. Wide range of application, can be used in gas, liquid, in gas subsonic, transonic and supersonic flow can be used; In addition to measuring the average velocity, the pulsation value and turbulence amount can also be measured. In addition to measuring single-direction motion, velocity components in multiple directions can also be measured simultaneously.

3. High frequency response up to 1MHz.

4. High measurement accuracy and good repeatability.

5. The disadvantage is that the probe has certain interference to the flow field and is easy to break.