Development of a cryoprobe system with a built-in thermocouple to improve the temperature measurement accuracy

Abstract

The conventional configuration of cryoprobe systems uses triple coaxial tubes. Moreover, in order to measure the temperature shift at the outer wall of the probe tip, a wired thermocouple was externally attached using an adhesive. However, as the adhesive works as thermal resistance, the temperature measurement accuracy deteriorates. To cope with the problem, in the proposed system, the outer and middle tubes of the triple coaxial tube were designed using two different metals, which are the materials used to build the thermocouple, and these tubes were welded only at the probe tip. As a result, the proposed system achieves a built-in thermocouple that does not need the adhesive. To evaluate and verify the effectiveness of the proposed system, the measuring accuracy was investigated. Through the experiments, we verified that the proposed system could more accurately measure the temperature shift at the probe tip as compared to conventional systems.