Design and application of high-pressure-withstand and microsecond-responsive surface high-temperature transducer

A new high temperature transducer is described. The transducer employs NiCr-NiSi thermocouple as a sensing-element and can directly measure flash surface temperature at 1230°C under high pressure up to 400 MPa. It can be reused by abrading the hot-junction after it ablated. The response time constant is less than 1 μs which was verified by theoretical calculation and by a calibrated test. This paper relates to the features of the transducer and the technology keys to the design of high-pressure-withstand poles, micrometer-order clearance between poles and high-resistance insulation. The theoretical analysis and calibration test are presented. The measurement results and curves of the inner-barrel surface temperature for a certain gun are given