A sensor (1) is disclosed for the measurement of moisture in a flow of material, especially loose material such as meal material, grains, granulates and similar materials which are to be pressed to form feed pills in presses, in connection with pre-processing such as the extrusion of feedstuffs, and for the measurement of a finished product, regardless of whether this is pelleted or extruded. The sensor (1) comprises a tube piece (2) of an electrically conductive material with circular cross-section, and an elongated pole (3) which is of circular cross-section and is disposed with its longitudinal axis (4) concentrically and electrically insulated in the tube piece (2), and which consists of an electrically conductive material.
When the moist material flows between the inside surface of the tube piece (2) and the outer side of the pole (3), the sensor (1) works as a condenser for the capacitive detection of the moistness, which can be determined on the basis of the detection.
There is hereby achieved a very accurate measurement of the content of moisture in the material, even though the material flows in a pulsating manner.