Ultrasonic probes for high temperature immersion measurements

Ultrasonic probes for high temperature measurements in immersion are presen ted. These probes consist of piezoelectric transducers and buffer rods, and may be operated in the pulse echo mode. The probes can operate to temperat ures as high as 215 degreesC without requiring a cooling system. For imagin g purposes, one end of the clad buffer rod is machined into a semi-spherica l concave shape, of which the purpose is to focus the ultrasound. The opera ting frequency is between 5 and 9 MHz. Ultrasonic images, produced using a mechanical raster scan with the probes fully immersed in silicone oil at el evated temperatures, are presented. The importance of the signal-to-noise r atio in the pulse-echo measurement is discussed.