Interlaboratory Comparison of the Co−C Eutectic Point with Small-Size Cell for Thermocouples

SUMMARY Using a small‐size crucible, interlaboratory comparison of the realization of the Co−C eutectic point was performed in the industrial field in Japan, with the aim of verifying the possibility of thermocouple calibration at the eutectic point with an existing furnace of less‐than‐ideal temperature distribution, namely, the palladium‐point wire‐bridge method furnace for thermocouple calibration. A small‐size crucible for thermocouples was made by the National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ/AIST). The interlaboratory comparison was piloted by the Tokyo Metropolitan Industrial Technology Research Institute (TIRI), a public test and research organization in Tokyo, and was conducted among five calibration laboratories including the pilot. One of the five laboratories is a designated calibration laboratory in Japan, and the other three are private laboratories. Four laboratories including TIRI used an existing palladium‐point furnace, and one laboratory made a new furnace for this interlaboratory comparison.