Method of measuring temperature

It is often necessary to measure the temperature in the interior of electrically conductive bodies, above all hot workpieces. This is possible, for example, by dividing them at a desired point. The invention concerns a method in which the electromagnetic waves originating from a coil through which current flows penetrate into the body. Here, the penetration depth of the waves depends on the frequency. The coil therefore has currents of different frequencies applied to it and, at each frequency, the current, the voltage and the effective power and, respectively, the phase shift are measured. These measured data are supplied to a computer, which calculates an image of the temperature over the cross section of the body. The advantage in this case is that a temperature measurement can be carried out over the cross section of the body without destruction and without contact.