ELECTROMAGNETIC GAUGE OF TUBE INNER RADIUS COMPENSATED FOR MATERIAL PROPERTIES AND COIL RADIAL OFFSET

摘要

Low-frequency electromagnetic measurement of inner radius of metal tubes is indispensable in their production and condition assessment. Two challenges in such a measurement are corrections for variations in electromagnetic properties of a tube and coil radial offset. The authors investigate adaptation of the single-coil method for measurement of inner radius to a small scale embedded system based on a DSP microcontroller. The electromagnetic gauge can be used for both magnetic and nonmagnetic tubes and its performances are comparable to the laboratory implementation of the method based on a precision RLC meter.