Apparatus and method for high temperature viscosity and temperature measurements

A probe for simultaneously measuring viscosity and temperature of a hot liquid, comprising:

• (a) a buffer rod comprising a refractory material acoustical waveguide comprising a first inner refractory material encased in a second outer refractory material, said buffer rod having a first and second end, said second end comprising a buffer rod probe surface, wherein the inner refractory material is a high temperature resistant, reduced heat sink material selected from the group consisting of alumina, silicon carbide and mixtures thereof;
• and
• (b) an ultrasonic shear wave generating transducer at the first end of the buffer rod;
• wherein said ultrasonic shear wave generating transducer emits shear waves that are in part transmitted and in part reflected at the interface between the two refractory materials;
• and
• wherein the shear waves reflected at the interface between the two refractory materials provide a reference signal that can be used to measure time differences.