Design Of Hot Film Anemometer Based On Constant Temperature Difference Method

Wind speed measurement, as an important element in the industry of Fluidflow measurements, is also the essential parameter and the technical specificationduring industrial processes, scientometrics and energy measurement. What’s more,wind speed measurement plays an important part during products qualityinsurance, production efficiency improvements, as well as resources saving. Inthis article, we are talking about the design of a kind of Hot Film Anemometer,which will be mainly applied on detecting the mine ventilation. During theborehole operation, such as coal mining，a too low wind speed does no good tohuman sweat evaporation and at the same time the gas will be easier toaccumulate. Well, there will be more risks for the production safety and humanhealth if the wind speed is too fast, as mine dusts float more easily. Therefore,mineral anemometer does matter both production safety and miners’ lives.This article discussed the design of a new hot film wind speed measurementsystem, which is powered from a constant temperature difference supplier. Thehot film sensor consists of two platinic electric resistances. One is to be heated,and the other is to be a component of measuring the environment temperature.The whole circuit is designed to be Constant Temperature Difference Controlling.This kind of CTD controlling circuit will supply the heat, which is consumed byairflow, through changing the current magnitude, so that the temperature betweenthe platinic electric resistances stays unchanged. The constant temperaturedifference minimizes the influence on measurement accuracy, and themeasurement range is expanded at the same time. In this design, we usedpolynomial data processing method on the linearization of the sensor signal, inorder to reduce the non-linearity. We also designed to apply the infrared remotecontrol technology on zero and sensitivity calibration. From the above, the wholedesign will make the system more reliable since there are no adjustable components used.In conclusion, the hot film anemometer, which is discussed and designed inthis article, will be with features of smaller size, lower costs and powerconsumption, as well as higher reliability, that provide itself a good marketprospect.