带“W”户外使用的PVC绝缘线将要求做Permitivity test（许可试验）。

 请问各位，这个Permitivity test（许可试验）具体是什么？

5.2.4 Permittivity and stability factor
5.2.4.1 Permittivity –″W″ Type cords
5.2.4.1.1 When tested in accordance with CSA C22.2 No. 0.3, Clause 4.28.4; UL 1581, Section 1020; or NMX-J-040-ANCE, the permittivity of the insulation shall be as follows:
(a) after 14 d of immersion the capacitance shall not be more than 10% greater than the capacitance measured after the first day; and
(b) after 14 d of immersion the capacitance shall not be more than 3% greater than the capacitance measured after 7 d.
5.2.4.1.2 Tests shall be made using three 5 m (16 ft) specimens of insulated conductor. Specimens shall be
(a) tested without any polyester tape or similarly non-absorptive separator; and
(b) selected before assembly into finished cord.
The middle 3 m (10 ft) of each specimen shall be immersed continuously in tap water in a temperature of 50 °C ± 1 °C for thermoset insulation or 60 °C ± 1°C for thermoplastic insulations for 14 d. The1m(3ft) end portions of each specimen shall be kept dry above the water as leakage insulation. A cover for the tank shall be placed directly above the surface of the water. The water level shall be kept constant. 

电容的变化率  (C14-C1)/C1<=10%    (C14-C7)/C7<=3%

［陈彬 在 2008-11-21 10:44:36 编辑过］