Abstract: A constant temperature anemometer wherein a bridge circuit having four legs includes a sensor in one leg and resistances in the other legs. The resistance of two of the legs is formed, at least in part, by a potentiometer which allows a simultaneous adjustment of the resistance of those legs and, accordingly, the ratio of those resistances. The potentiometer may be selectively connected within the bridge circuit or, alternatively, with other circuitry to determine the operating resistance of the sensor.