When selecting connectors, there are numerous factors to consider, with environmental parameters being one of the more crucial. This includes factors such as temperature, humidity, and air pressure. The usage method of connectors varies under different environmental conditions; for instance, using them in spaces with high temperature and humidity can significantly reduce the lifespan of the interfaces. Below, we introduce some usage tips for extreme environments.
High-temperature environment
The metal and insulating materials of connectors determine the operating temperature environment. High temperatures can damage the insulating material, leading to reduced insulation resistance and voltage withstand performance; for metals, high temperatures can cause contact pairs to lose elasticity, accelerate oxidation, and deteriorate coatings. The typical environmental temperature range is -40 to 80°C, with special applications potentially requiring higher temperatures.
2. Humid Environment
High relative humidity, greater than 80%, is a significant cause of electrical breakdown. A damp environment leads to the absorption and diffusion of water vapor on the surface of insulators, which can easily reduce the insulation resistance to below MΩ levels. Prolonged exposure to high humidity can cause physical deformation, decomposition, and the release of by-products, leading to respiratory effects, as well as electrolysis, corrosion, and cracking. Particularly for USB connectors on the exterior of equipment, environmental conditions such as dampness, water penetration, and contamination must be considered. In such cases, sealed connectors should be selected.
3. Rapid temperature change environment
The humidity shock test simulates the actual usage scenario of USB connectors transitioning from cold to warm environments, or mimics the rapid temperature changes experienced by spacecraft and probes. Sudden temperature fluctuations may cause cracking or delamination in insulating materials.
4. Thin air environment
At high altitudes with thin air, plastics release gases that contaminate contact pairs, increasing the tendency for corona discharge, reducing voltage withstand capability, and causing short-circuit faults in the circuit. When reaching a certain altitude, the performance of the plastics deteriorates. Therefore, when using non-sealed connectors at high altitudes, derating usage is mandatory.
5. Corrosive Environment
According to the different corrosive environments in which connectors are used, the appropriate metal, plastic, and coated connectors should be selected. For instance, connectors used in salt fog environments can rapidly degrade in performance if they lack corrosion-resistant metal surfaces. In environments with significant concentrations of SO2, it is not advisable to use connectors with silver-plated contact pairs. In humid and hot regions, mold is also a significant issue.
