Small Vacuum Chamber B consists of a vacuum vessel and vacuum pumps, and it is used mainly to perform thermal vacuum tests on small materials and equipment. The vacuum pumps evacuate air from the vacuum vessel to achieve a high-vacuum (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 measurements inside the vacuum chamber.