Technical analysis of EX-JDM1 explosion-proof digital anemometer

EX-JDM1 explosion-proof digital anemometer technology analysis is a speed measuring instrument that converts flow rate signals into electrical signals, and can also measure fluid temperature or density. The principle is that a thin metal wire heated by electricity is placed in the airflow, and the heat dissipation in the airflow is related to the flow rate, and the heat dissipation causes the temperature change and the resistance change, and the flow rate signal is converted into an electrical signal.

Two working modes:

① Constant current type. When the current is kept constant, the resistance changes when the temperature changes, and therefore the voltage at both ends changes, thereby measuring the flow rate. ② Constant temperature type. The temperature remains constant, such as 150°C, and the flow rate can be measured according to the required current. Constant temperature type is more widely used than constant current type. The length is generally in the range of 0.5-2 mm, the diameter is in the range of 1-10 microns, and the material is platinum, tungsten or platinum-rhodium alloy. If a thin metal film is used instead of the metal wire, it is a hot film anemometer. Its function is similar to that of a hot wire, but it is mostly used to measure the liquid flow rate. In addition to the ordinary single-wire type, it can also be a combined two-wire type or three-wire type to measure the velocity components in all directions. The output electrical signal is amplified, compensated and digitized and then input to the computer, which can improve the measurement accuracy, automatically complete the data post-processing process, and expand the speed measurement function, such as simultaneously completing the instantaneous value and the time average value, the combined velocity and the sub-velocity, the turbulence and Measurement of other turbulence parameters. Compared with the Pitot tube, the anemometer has the advantages of small probe volume, less interference to the flow field; fast response, can measure unsteady flow velocity, and can measure very low speed.

Mechanical And Electrical Equipment

Mechanical Electrical Equipment Industry,Popular Integrated Operation Vehicle,Railroad Tunnel Cleaning Vehicle,Railroad Spraying Cleaning Vehicle