中国女人性猛交 I 中国女人真人一级毛片 I 中国人与拘一级毛片 I 中国色老太hd I 中国少妇色 I 中国特级黄色片 I 中国特级毛片 I 中国一级黄色 I 中国一级黄色大片 I 中国一级特黄真人毛片免费观看 I 中日韩精品一区二区三区 I 中日韩毛片 I 中日韩男男gay无套 I 中日韩一级片 I 中日韩在线 I 中日韩中文字幕 I 中文av电影 I 中文av网 I 中文av网站 I 中文av在线播放 I 中文av字幕 I 中文二区 I 中文国产 I 中文国产字幕 I 中文精品视频 I 中文久久 I 中文久久久 I 中文久久乱码一区二区

The three main properties of waterproof connectors are mechanical performance, electrical performance, and environmental performance. Let's give you a detailed explanation below.

1. Environmental performance

Common environmental properties include temperature resistance, humidity resistance, salt spray resistance, vibration resistance, impact resistance, etc.

Temperature resistance: Currently, the maximum working temperature of waterproof connectors is 200 ℃ (except for a few high-temperature dedicated ones), and the minimum temperature is -65 ℃. During operation, the current generates heat at the contact point, leading to an increase in temperature. Therefore, it is generally believed that the working temperature should be equal to the sum of the ambient temperature and the temperature rise at the contact point. Some specifications explicitly specify the allowable temperature rise at the rated working current.

Salt spray resistance: When working in an environment containing moisture and salt, the surface treatment layer of the metal structure and contact parts of the connector may cause electrochemical corrosion, which affects physical and electrical performance. In order to test the connector's ability to withstand this environment, a salt spray test is specified. Hang the connector in a temperature control test chamber and spray a specified concentration of sodium chloride solution with compressed air to form a salt mist atmosphere. The exposure time is specified in the product manual and should be at least 48 hours.

Resistance to vibration and impact: Resistance to vibration and impact is an important performance of electrical waterproof connectors, especially in special application environments such as aerospace, railway and highway transportation. It is an important indicator for testing the firmness of mechanical structures and electrical contact reliability. There are clear provisions in relevant testing methods, and peak acceleration, duration, pulse waveform, and electrical continuity interruption time should be specified in impact tests.

Moisture resistance can affect the insulation performance of connection H and corrode metal parts. The constant humidity test conditions are a relative humidity of 90% to 95% (up to 98% according to the product manual), a temperature of 40 ± 20 ℃, and a test time of at least 96 hours according to the product regulations. The alternating damp heat test is more stringent.

2. Mechanical properties

In terms of connection function, insertion and extraction force is an important mechanical performance. Insertion force is divided into insertion force and extraction force (also known as separation force), and their requirements are different. The insertion force should be very small (resulting in a structure with low insertion force LIF and no insertion force ZIF), and if the separation force is too small, it will affect the reliability of contact. Another important mechanical property is the mechanical lifespan. Mechanical life is actually a durability indicator, referred to as mechanical operation in GB5095. It takes one insertion and extraction as a cycle to determine whether its connection function (such as contact resistance value) can be completed normally after the specified insertion and extraction cycle.

The insertion and extraction force and mechanical life are related to the contact structure (positive pressure), the coating quality of the contact parts (Sliding friction coefficient) and the dimensional accuracy (alignment) of the contact parts.

3. Electrical performance

The main electrical properties of waterproof connectors include contact resistance, insulation resistance, and electrical strength.

① Insulation resistance is an indicator that measures the insulation performance between contacts and between contacts and the shell, ranging from a few hundred megaohms to several tens of megaohms.

② Electrical strength, also known as withstand voltage and dielectric withstand voltage, is the ability to withstand the rated test voltage between contacts or between contacts and the casing.

③ High quality electrical waterproof connectors with contact resistance should have low and stable contact resistance, ranging from a few milliohms to several tens of milliohms.