Patent attributes
An anemometer circuit comprises a sensor having a resistance which varies with temperature, immersed within a moving medium, the mass flow rate of which is to be determined. A control loop causes a current to flow through the sensor resistance, and varies the current as needed to maintain the sensor temperature at a desired value; the current is proportional to the medium's mass flow rate. In a preferred embodiment, a controller measures the sensor's voltage and current and the ambient temperature of the medium, and varies the current such that the sensor dissipates the power required to maintain its temperature at the desired value. The control loop can be arranged to maintain the sensor at a constant temperature, or at a constant differential temperature with respect to the medium's ambient temperature.
