FLOW SENSOR WITH THERMOCOUPLES

A device for measuring the flow of a fluid comprises a substrate (1) and a heater (4) arranged on the substrate (1). At least one first and at least one second sensing thermocouple (5,6) are arranged on the substrate (1) on opposite sides of the heater (4) for generating a sensing signal (”T) proportional to a temperature difference between a location upstream and downstream from the heater (4), wherein a junction (51,61) of the sensing thermocouples (5,6) closest to the heater (4) is arranged at a first distance (d1) from the heater (4). At least a first and a second monitoring thermocouple (9,10) are arranged on the substrate (1) on opposite sides of the heater (4) in parallel to the sensing thermocouples (5,6) for generating a monitoring signal (TP), wherein a junction (91,101) of the monitoring thermocouples (9,10) closest to the heater (4) is arranged at a second distance (d2) from the heater (4), wherein the second distance (d2) is equal to or more than the first distance (d1). A control circuit (18) is adapted to measure a flow of the fluid over the heater (4) and the sensing thermocouple (5,6) subject to the sensing signal (”T) and the monitoring signal (TP).