(1) Equipment
Megger for testing instruments: It should comply with the provisions of GB1410-78 "Test Methods for Insulation Resistance, Volume Resistivity and Surface Resistivity of Solid Electrical Insulating Materials".
Electrode: According to the regulations of GB14l0-78, it is made of pin foil with a thickness not exceeding 0.01mm. Use a small amount of medical vaseline or capacitor oil or magnetic oil to stick on the surface of the sample, and press the aluminum foil with a steel electrode with the same diameter at a pressure of 0.196Pa. The diameter of the measuring electrode is 50±0.2mm, and the inner diameter of the protective electrode is 54mm± 0.2mm, outer diameter 74mm, the bottom plate of the sample is a high-voltage electrode.
(2) Sample
See Table 10-1
(3) Test procedure
The sample should be treated for 24 hours at 23°C ± 2°C and the relative humidity is 50% ± 5%, and measured under these conditions.
The immersion temperature of the sample is 23°C±2°C. After soaking in water for a week, wipe the surface of the sample with paper, put the electrode on it, and measure it immediately. The test voltage is DC 100V±5V, 500V±25V or 1000mV±50V.
Record the volume resistance after immersion in water for 24 hours, 48 hours and 96 hours.
(4) Results
The volume resistivity was calculated as follows:
