Abstract: A hot film dual element fluid flow sensing device has its two hot-film sensors arranged in-line on an elongate support. A flow deflection collar is situated midway on the support between the two flow sensors and deflects the flow away from the sensor situated behind the collar. Underlying the sensor films of the two flow sensors and electrically insulated from those sensor films is an electrical heater. In operation of the device, the heater and the sensor films are electrically heated to about the same temperature to inhibit heat transfer therebetween. Because of that arrangement, the device responds rapidly to changes in fluid flow because virtually all the heat lost by the sensor films is transferred directly into the surrounding fluid.