High temperature ultrasonic sensor for the simultaneous measurement of viscosity and temperature of melts

An ultrasonic sensor that simultaneously measures temperature and viscosity of molten materials at very high temperature is described. This sensor has applications as a process monitor in melters. The sensor is based on ultra sonic shear reflectance at the solid-melt interface. A delay line probe is constructed using refractory materials. A change in the time of flight with in the delay line is used to measure the temperature. The results obtained from this sensor on various calibration glass samples demonstrate a measure ment range of 100-20 000 P for the viscosity and 25-1500 degrees C for the temperature. (C) 1999 American Institute of Physics. [S0034-6748(99)01912-7 ].