Abstract: The flow monitoring device is used with a pump casing on an outflow tube having a passageway therethrough with a wall thereabout. A solenoid pump communicates with the passageway for providing pulsatile liquid flow therethrough. A reduced-in-thickness area along the wall of the casing or outflow tubing has an outside surface establishing a site to measure pulsatile flow along an adjacent inside surface. A thermistor is mounted on the outside surface of the wall area for sensing the temperature thereof in response to pulsatile flow therebeneath. The thermistor is electrically energized at a predetermined level. A control circuit regulates the input of electrical energy to the thermistor for predetermined time periods. The control circuit includes a sample and hold circuit and a reset switching circuit responsive to the pump activation for supplying thermistor power after pumping begins.