Water-cooled eddy-current transducer for testing product while at high temperature

Claim 1

A transducer for testing elongated product at elevated temperature comprising a length of tube of high temperature resistant material, said tube having a plurality of centrally disposed circumferential grooves therearound and an internal dimension sufficient to admit said product axially, an inductor coil and sensor coils wound around said tube in said grooves, a layer of heat resistant electrically insulating tape between said coils and said length of tube, end plates secured in abutting engagement with the ends of said length and having ports therein generally alined with the opening through the length, an outer wall surrounding said length in spAced relationship therewith and engaging said plates, an enclosing sleeve telescoped over said length with a small clearance therebetween, said enclosing sleeve being in abutting engagement with said ends to form a coolant chamber with said outer wall, a thermal conductive plastic filling said small clearance, an inlet port in said outer wall for admitting a liquid coolant into said coolant chamber, an outlet port in said outer wall for discharging said liquid coolant from said coolant chamber, a nipple extending generally radially from said length through said coolant chamber and said outer wall and a packing gland set on said outer wall, with said nipple extending through said gland and secured to said sleeve.