Device for providing an electrical signal proportional to the thickness of a measured coating with an automatic range switch and sensitivity control

摘要

A device for measuring the thickness of coatings, wherein a thickness gauge is electrically coupled to a circuit intended to convert the electric signal at the output of said thickness gauge into an electric signal proportional to the thickness of the coating. The conversion circuit comprises a peak detector whose output is electrically coupled to inputs of an automatic measurement range switching unit and a subtractor. Another input of the automatic measurement range switching unit is connected to an output of a reference voltage forming unit, its one output is electrically coupled to another input of the subtractor, another output is connected to an input of an adder, whereas a third output is electrically coupled to an input of a measuring sensitivity control unit. An output of the subtractor is connected to another input of the measuring sensitivity control unit whose output is connected to another input of the adder. The output of the adder serves as the output of the conversion circuit and is connected to recorder.