IST INNOVATIVE SENSOR TECHNOLOGY FS1.A.1L.195

The FS1 series Flow Sensor Element that consists of two temperature depending platinum-resistors, both deposited on one chip. The low-ohm resistor with a small area is used as a heater, whereas the other high-Ω resistor serves to measure the reference temperature. Using a bridge circuit, the differing resistance value of two elements leads to different (self) heating. The (self) heating is dependent upon the applied voltage, the mass flow and the media in which the sensor is located. Higher voltage increases self heating, a higher flow rate increases cooling. If the self heating is kept constantly by a suitable controller, the voltage increases with higher flow rates and therefore becomes a measure for the mass flow. As a result of his little thermal mass, this sensor has fast heating and cooling response times. The measuring principle of the sensor can be used for large operation ranges, from 0 to 0.1 up to 100m/s.