METHOD AND APPARATUS FOR EVALUATING SURFACE TREATMENT OF SUPERCONDUCTING CERAMICS

PURPOSE:To evaluate deterioration of a surface treatment by putting a specimen formed by attaching electrodes at 4 points of a square bar made of superconducting ceramics repeatedly into and out of a low-temp. liquid and measuring the voltage value of the specimen in the atm. when constant current is passed thereto by a 4-terminal method. CONSTITUTION:The specimen is prepd. by attaching the electrodes to 4 points of the square bar of the superconducting ceramics to be subjected to evaluation and decision of whether the surface treatment is acceptable or rejective. This specimen is repeatedly put into and out of the low-temp. liquid and the voltage in the atm. when the constant current is passed to the electrodes by the 4 terminal method is measured. The superconducting phenomenon of the specimen is decided by a change in said voltage and whether the surface treatment of the superconducting ceramics constituting the specimen is acceptable or rejective is evaluated.