美女胸被狂揉扒开吃奶的网站o_亚洲日韩av中文无码专区_东京热激情无码专区_久久HEZYO久综合亚洲色_欧美成人高清视频_国产精品乡下勾搭老头_欧美一级v片在线播放_成人午夜国产视频_男女猛烈无遮挡免费动态图_亚洲一区国产精品视频

首頁 > 國外線纜

[問題求助] Permitivity test(許可試驗)

P:2008-11-19 18:47:43

1

帶“W”戶外使用的PVC絕緣線將要求做Permitivity test(許可試驗)。

 請問各位,這個Permitivity test(許可試驗)具體是什么?

NPC - National Patent Commission全國專利委員會(美) (0) 投訴

P:2008-11-21 10:32:48

2

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. 

電容的變化率  (C14-C1)/C1<=10%    (C14-C7)/C7<=3%

[陳彬 在 2008-11-21 10:44:36 編輯過]

monitor core - 監(jiān)視線芯 (0) 投訴

P:2008-11-21 16:27:21

3

指水中電容率和穩(wěn)定因素測試.很多"W"料目前還通不過,國內(nèi)沒有合格的測試試備,所以UL 現(xiàn)在還沒有非常強調(diào)要強執(zhí)抽檢.

Exclusive agency agreement - 獨家代理協(xié)議 (0) 投訴

3


你需要登錄才能發(fā)表,點擊登錄。