The Flow Sens owns for water and water mixtures optimized design 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-ohm 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. The Flow Sens is also available with a plastic housing of Æ 6mm.
This option provides the user with ideal opportunities to incorporate the element into custom-built applications or
specific housings, e.g. into a T-piece.