The note documents briefly work done on what is thought to be a new method of measurement of the pulsating flow in the intake port ot and SI engine and in the EGR returen line. The work reviewed has been carried out in close cooperation with Civ. Ing. Michael Føns, Civ. Ing. Christian Jepsen, the author (IAU) and Spencer C. Sorenson (ET). The theory which decribes in detail the overall dynamic chracteristics of the sensor was developed at IAU and ET, DTU.