Abstract: A method for capacitively measuring the thickness of multi-layer films (10), the layers (32, 34) the dielectric constants of which differ at least at a particular temperature, wherein, in addition to the capacitive measurement, at least one further thickness measurement is carried out under different conditions, and wherein the thicknesses (d1, d2) of the individual layers is determined by comparing the measurement results and by means of the different dielectric constants.

Abstract: A method for measuring the film thickness with the help of a measuring head (12), which is held with a holding device (14) against the film (10), so that the latter is deflected, wherein the reaction force (F), exerted by the film (10) on the measuring head (12), is measured and controlled to a specified nominal value by the movement of the measuring head.

Abstract: A sensor for the capacitive measurement of film thicknesses, with a drum (10), which rolls along the film (12) and has at least one measuring capacitor (C1-C4), the plates of which are disposed in the peripheral surface of the drum (10), so that its capacitance is effected by the thickness of the firm, and with a transformer (26), for transmitting the measurement signal from the rotating drum (10) to the stationary part (28), where an oscillator (OSZ1-OSZ4), which is integrated in the drum (10), generates a frequency signal (24), which depends on the capacitance of the measuring capacitor (C1-C4).