Method for determining flow speed in gaseous and liquid medium, involves adjusting frequency of heating voltage, and determining flow speed from changes of flow-dependant damped temperature waves, which lead to changes of resistance value

摘要

The method involves bringing a heating resistor (12) in contact with gaseous and liquid medium (24). The heating resistor is subjected with a periodically changing heating voltage. A frequency of the heating voltage is adjusted so that the resistor couples temperature waves in the medium. A flow speed is determined from changes of the flow-dependant damped temperature waves, which lead to changes of a resistance value. A temperature-dependant measuring resistor (14) is arranged in a distance (15) to the heating resistor, where the resistors are designed as wire resistors. Independent claims are also included for the following: (1) a device for implementing a method for determining flow speed in gaseous and liquid medium (2) a sensor.