Ultrasonic test head for nondestructibly testing hot specimens

摘要

In a gastight housing 2 (Figure 1) of an ultrasonic test head capable of accepting temperatures of 300 DEG C during continuous operation, the electroacoustic transducer 1 is coupled to the sonic transmission wall 21, which acts as a metallic protection layer, via a liquid coupling agent, in particular isomeric polyphenol ether, in the slit-type gap 3. The coupling agent is always at a pressure which is higher than the vapour pressure of the coupling agent at the working temperature. An absorbent ceramic paper 4 having suitable temperature resistance is used as a reservoir for the coupling agent. A spring 8 and a pressure piece 7 produce the minimum pressure for the coupling agent. <IMAGE>