"Insulation resistance refers to the resistance value that occurs when a voltage is applied to the insulated portion of a connector, causing leakage current to occur within or on the surface of the insulated portion.". It is mainly affected by insulation materials, temperature, humidity, dirt, and other factors. The insulation resistance values provided on the connector sample are generally indicator values under standard atmospheric conditions, and under certain environmental conditions, the insulation resistance values may decrease to varying degrees.

1、 Safety parameters

"Insulation resistance refers to the resistance value that occurs when a voltage is applied to the insulated portion of a connector, causing leakage current to occur within or on the surface of the insulated portion.". It is mainly affected by insulation materials, temperature, humidity, dirt, and other factors. The insulation resistance values provided on the connector sample are generally indicator values under standard atmospheric conditions, and under certain environmental conditions, the insulation resistance values may decrease to varying degrees. In addition, pay attention to the test voltage value of the insulation resistance. According to insulation resistance (M Ω)=voltage applied to the insulator (V)/leakage current（ μ A) Applying different voltages leads to different results. In the connector test, the applied voltage generally includes three levels: 10V, 100V, and 500V.

2、 Withstand voltage

Withstand voltage refers to the critical voltage between the mutually insulated parts of a contact pair or between the insulated parts and ground that can withstand within a specified time period higher than the rated voltage without causing breakdown. It is mainly affected by the contact pair spacing, creepage distance, and geometry, insulator material, as well as ambient temperature and humidity, and atmospheric pressure.

3、 Combustibility

Any connector cannot operate without electrical current, which poses a risk of fire. Therefore, the connector is not only required to prevent ignition, but also to be able to self extinguish in a short time in case of ignition and fire. When selecting electrical connectors, attention should be paid to selecting flame-retardant, self-extinguishing insulating materials.

4、 Mechanical parameters

Single Leg Separation Force and Total Separation Force

Contact pressure is an important indicator in connectors, which directly affects the magnitude of contact resistance and the amount of wear on the contact pair. In most structures, direct measurement of contact pressure is quite difficult. Therefore, contact pressure is often indirectly measured through the single leg separation force. For circular pinhole contact pairs, the ability of the female contact to hold the weight is usually tested using a standard pin with a specified weight weight. Generally, the diameter of the standard pin is the lower limit of the diameter of the male contact, which is taken as - 5 μ m。 The total separation force is generally twice the sum of the upper line of the single leg separation force. When the total separation force exceeds 50N, it is quite difficult to use manual insertion and extraction. Of course, for some testing equipment or certain special requirements, zero insertion and withdrawal force connectors, automatic release connectors, and so on can be selected.

5、 Environmental parameters

Environmental parameters mainly include environmental temperature, humidity, temperature fluctuations, atmospheric pressure, and corrosive environments. The environment in which connectors are used, stored, and transported has a significant impact on their performance, so appropriate connectors must be selected based on actual environmental conditions.

6、 Ambient temperature

The metal and insulating materials of a connector determine the operating ambient temperature of the connector. High temperatures can damage the flange material, causing a decrease in insulation resistance and withstand voltage performance; For metals, high temperatures can cause contact pairs to lose elasticity, accelerate oxidation, and cause coating deterioration. The normal ambient temperature is - 55~100 ℃, which may be higher in special situations.

7、 Wet

Relative humidity greater than 80% is the main cause of electrical breakdown. Wet environments cause the absorption and diffusion of water vapor on the surface of insulators, which can easily reduce the insulation resistance to below the M Ω level. Prolonged exposure to high humidity environments can cause physical deformation, decomposition, and escape of products, resulting in respiratory effects, electrolysis, corrosion, and cracks. Especially for connectors outside the equipment, it is often necessary to consider the environmental conditions of humidity, water infiltration, and pollution. In this case, sealed connectors should be selected. For water tight and dust tight connectors, the housing protection grade of GB4208 is generally used to indicate.

8、 Temperature jump

The humidity sudden change test is to simulate the actual use of connector equipment in a cold environment to a warm environment, or to simulate rapid changes in the ambient temperature of space vehicles and detectors. Sudden temperature changes may cause cracks or delamination of the insulating material.

9、 Atmospheric pressure

At high altitudes with thin air, plastic emits gases that contaminate the contact pairs, increasing the tendency for corona generation, reducing voltage withstand performance, and causing short circuit faults in the circuit. When reaching a certain value at high altitude, the performance of plastics deteriorates. Therefore, when using unsealed connectors at high altitude, they must be derated for use. The recommended voltage derating coefficients at low air pressure are shown in Table 2.

10、 Corrosive environment

Depending on the corrosive environment in which the connector is used, connectors with corresponding metal, plastic, and plating structures are selected, such as those used in salt fog environments. If there is no anti-corrosion metal surface, the performance will rapidly deteriorate. In environments containing considerable concentrations of SO2, connectors with silver plated contact pairs should not be used. In hot and humid areas, mold is also an important issue.