ELECTROMAGNETIC THICKNESS GAUGE Russian patent published in 1999 - IPC

FIELD: measuring equipment, applicable for measurement of thickness of various coatings on cylindrical metal bases. SUBSTANCE: the thickness gauge uses a microcontroller, programmable frequency divider, primary transformer converter with one exciting and two measuring windings, series-connected follower, operational amplifier and an AND gate. One of the microcontroller outputs is connected to an indicator. In addition the thickness gauge has a generator and a primary eddy-current converter connected to it. The eddy-current converter is fixed to a cylindrical body that is common for the transformer convertor. The transformer converter is located under the eddy-current converter and spring-loaded to the surface to be measured. Both converters make up a primary measuring converter, whose body an angular cut-out in the lower part. The eddy-current converter makes it possible to measure the diameter of the article. EFFECT: enhanced accuracy of measurements without calibration of the instrument at checking of coatings on cylindrical articles with differing radii. 4 dwg