Small Vacuum Chamber B consists of a vacuum vessel and vacuum pumps, and is mainly used to perform thermal vacuum tests on small materials and equipment. The vacuum pumps evacuate air from the vacuum vessel to achieve a high-condition (vacuum level: 1.3 × 10-3 Pa). Small Vacuum Chamber B is also equipped with a temperature control plate inside the chamber, allowing adjustment of the specimen temperature. In addition, it has 20 ports for connecting thermocouples, enabling temperature measurement inside the vacuum chamber.