A cryogenic system has been established to measure electrical properties of insulation materials. The cryostat in the system contains two operating modes: 4.2 K and 1.65 K. A G-M cryocooler is used as cold source in these two modes. In 4.2 K mode, samples were directly cooled by the copper plates connected to the second stage of the cryocooler. In the 1.65 K mode, the helium gas is liquefied. The superfluid ⁴He (He-Ⅱ) of 1.65 K was obtained by throttling and depressurizing the liquid ⁴He (He-Ⅰ). The thermal switch in the 1.65 K mode can reduce the precooling time by 11.6 h and saved 22.5 L of helium. The transforming of the two modes is controlled by four threaded rods which are connected to the first and the second stage flange. The electrical test unit is designed, including the breakdown strength test and the flashover characteristics test with the voltage from 0 to 100 kV, which realizes the coupling of low temperature and high voltage.

已经建立了低温系统来测量绝缘材料的电性能。系统中的低温恒温器包含两种操作模式：4.2 K 和 1.65 K。在这两种模式下，使用 GM 低温冷却器作为冷源。在 4.2 K 模式下，样品由连接到低温冷却器第二级的铜板直接冷却。在 1.65 K 模式下，氦气被液化。超流⁴ 1.65的K（赫-Ⅱ）他由节流和减压的液体获得的⁴他（He-Ⅰ）。1.65 K 模式下的热敏开关可将预冷时间减少 11.6 小时，并节省 22.5 L 的氦气。两种模式的转换由连接到第一和第二级法兰的四个螺纹杆控制。设计了电气试验单元，包括击穿强度试验和0～100kV电压的闪络特性试验，实现了低温与高压的耦合。