97人妻成人免费视频,伦wwwhd老女人,宾利AV影视在线观看,少妇黄色电影一区二区三区

scroll

National standard cable and non-standard cable

2022-12-19 10:57:56 浙江安和線纜股份有限公司 Viewd 490

When choosing cables, choose cables according to your own site usage, and don't covet cheapness.Thinking that the cable is cheap and guaranteed to be of the national standard, nine out of ten are marginalized.Fool users who are unprofessional and do not understand the industry.In order to enable the majority of users to more clearly understand the quality standards of cables and wires and self-judge the difference between national standards and non-standard standards.Below we combine the actual situation that engineering users and the cable industry often encounter, so that everyone can have a simple understanding.


 Cables and wires are generally used in engineering users and construction projects. There are mainly these three types of cables.:


1. National standard cables: Cables produced according to the technology of relevant cable standards issued by the state are referred to as international cables.


2. Line marking cables: According to industry standards, there are mainly fewer cutting corners, but it does not affect the performance of large-scale use.


3. Non-standard cables: products that are designed to meet the needs of the market. Nowadays, the application of wire and cable is becoming more and more extensive, and with it, there are more and more types of wire and cable sold on the market.


So, how to distinguish between the "national standard" and "non-standard" of wire and cable?


It is recommended that you take a look, try twice, weigh three times, compare the price four times, look at the copper quality five times, check the quality six times, and know the six tricks.


Take a look: it depends on whether the wire and cable products have a quality system certification certificate, whether the certificate of conformity is standardized, whether there is a factory name, factory address, inspection seal, and production date, and whether there are trademarks, specifications, voltages, etc. printed on the wires.It also depends on the cross-section of the copper core of the wire. The high-grade copper has a bright color and soft color, otherwise it is a defective product.


Second try: It is advisable to bend a wire head repeatedly by hand. Anything that feels soft to the touch, has good fatigue strength, plastic or rubber feels elastic to the touch, and there are no cracks on the wire insulator is an excellent product.


Three weighing weights: for good-quality wires and cables, the weight of each 100m is generally within the specified weight range.For example, the commonly used plastic insulated single-strand copper core wire with a cross-sectional area of 1.5mm2 weighs 1.8-1.9 kg per 100m; plastic insulated single-strand copper core wire with a cross-sectional area of 2.5mm2 weighs 3-3.1 kg per 100m; plastic insulated single-strand copper core wire with a cross-sectional area of 4.0mm2 weighs 4.4-4.6kg per 100m, etc.The weight of the poor-quality wire is insufficient, either the length is not enough, or the copper core of the wire has too many impurities.If it is a cable, especially a large-size cable, the best way to weigh the quantity is to reflect whether the copper content of the cable is up to the standard and whether the conductor cross-section is up to the standard. Generally, there are cables with small cross-sections made of copper. If the copper content of the cable is weighed and does not reach the weight range of the error allowed by the national regulations, it can basically be regarded as non-standard.


Four-to-one price: Due to the low production cost of counterfeit and shoddy wires, vendors often sell at low prices under the guise of cheap and good quality when selling, making people fooled.Therefore, when buying, be careful not to be dazzled by the "good quality and low price" advertised by the merchant and be deceived.Five look at the copper quality.Qualified copper core wire copper core should be fuchsia, shiny, and soft to the touch.


Five, look at the copper material: The copper core of the shoddy copper core wire is purple-black, yellowish or white, with many impurities, poor mechanical strength and poor toughness. It will break with a little force, and there is often disconnection in the wire.During the inspection, you only need to peel off one end of the wire for a while, and then rub it slightly on the copper core with a piece of white paper. If there is a black substance on the white paper, it means that there are more impurities in the copper core, and it can be considered a "non-standard" wire and cable.


Six. Quality inspection: In the case of differences in the quality of the cable, it can be sent to a third-party inspection agency for inspection.Based on whether the authoritative test report is qualified.


久艾草在线视频免得| 熟女大屁股白浆一区二区| 爆乳无码AV一区二区三区| 国产日韩精品视频无码| 亚洲日本在线在线看片4k超清| 日本成人午夜不卡视频| 高清毛片视频免费观看| 成人无码精品无码亚洲社区| 成年人免费9视频在线| 麻豆黑人蜜桃国产精品无码牛牛| 美女又黄又爽又乳的视频网站| 亚洲av日韩av无码全网| 久久亚洲AV成人无码国产漫画| 精品国产综合成人亚洲区2022| 亚洲AV无码精品日韩一区二区| 国产精品亚洲二区在线播放| 国产V亚洲V天堂无码| 国产av巨作精品原创| 国产在线观看无码的免费网站| 精品久久久久久无码成人| 日本卡2卡3卡4卡5卡精品视频| 国产精品一区二区久久久蜜桃| 精品久久久久久无码成人| 亚洲欧洲自拍偷线高清一区二区| 一个人看的www免费观看视频| 亚洲AV噜噜狠狠网址蜜桃尤物| 亚洲国产精品久久久久蜜桃噜噜| 乱码丰满人妻一二三区麻豆|