The sensor acts as a hot film anemometer in CTA (Constant Temperature Anemometer) mode. In this case, two resistors located in the actual media flow with precisely specified temperature coefficients and three resistors outside the flow are connected to form a bridge. The first resistor in the media flow (RT) measures the fluid temperature, the second resistor of lower impedance (RS) is always heated to such a point that it is held at a fixed, specified temperature above the fluid temperature. The heating current required for this is a measure of the heat dissipation through the flowing gas and represents the primary measured variable.
Function diagram of the inline sensor