Abstract: The present apparatus scans a torch or other member in two directions contained in a scanning plane perpendicular to its advance direction. The apparatus includes means for controlling the speed of the torch in one direction and a means for controlling the position of the torch in the other direction are provided. There is also a position coder in accordance with the first direction supplying a signal which is compared with a reference amplitude, the result of the comparison supplying a signal for synchronizing the movements of the torch in said direction. Regulating means for defining the path of the torch in the scanning plane are also provided.

Abstract: The invention relates to a multiple coil eddy current probe equipped with a coil balancing device. This probe comprises several coils forming an eddy current probe supplying in each case one signal. Each coil is regulated to overvoltage by a regulating unit, which acts on the frequency of the high frequency oscillator supplying each coil. Application is to the automatic positioning of a welding torch and to the inspection of the weld.