Anemometer with an Intermittently Heated Transistor as a Sensor

抄録

A thermal anemometer using a transistor as a sensor has been constructed and tested. The sensor is intermittently heated electrically so that its temperature goes up and down periodically between two prescribed limits. Since the time required for the temperature to rise to the upper limit depends on the speed of the surrounding fluid, we can use the time detected to determine the velocity of the fluid. The anemometer works under small temperature differences between the sensor and the fluid. It is highly durable, and shows a high sensitivity to wide range of fluid speeds.