Electricity the manner null which detects the wall thickness change of the hollow body which conducts

摘要

The method is based on the exploitation of the ''skin effect'' occurring in any current-conducting material as a function of the current frequency going through said material. A transformer (5) is supplied from a generator (2) and an amplifier (4) to produce the current intended to supply the tube (T) and to measure the voltage at the terminals of a shunt (6). This voltage which is characteristical of the energization current is amplified by an amplifier (8) and brought to the reference input of a phase correlation amplifier (1). The resistive component of the signal on the tube is then measured by said amplifier (1) by just measuring the signal phase component.