The purpose of high temperature test is to determine the ability of components, equipment or other products to be used, transported or stored in high temperature environment. High temperature test is one of the climate and environment test items with high frequency. High temperature stress is also one of the commonly used stress types in reliability test. The test procedure of high temperature test includes: pretreatment - initial detection - condition test - intermediate detection - recovery - final detection.

Test standard: GB / T 2423.2; IEC 60068-2-2； EIA-364-17

Low temperature test is a commonly used test type in climate and environment test.

Low temperature test purpose: to determine the environmental adaptability of the product under low temperature storage or low temperature working conditions.

Low temperature test content: low temperature operation test, low temperature storage test, low gas start or cold start test

Applicable occasions of low temperature test: low temperature test is mainly applicable to products that may be affected by low temperature environment. Low temperature environment test is used to stimulate the inherent defects of products.

Test conditions of low temperature test: low temperature point, low temperature test time and temperature change rate.

Test standard: GB / T 2423.1; IEC 60068-2-1； EIA-364-59

Quickly switch the high temperature and low temperature at the set time and frequency, and test the rapid temperature change of the test object to detect the physical change of the test object in the rapid temperature change. Using the acceleration technique of artificial simulated ambient temperature (when circulating within the upper and lower extreme temperatures, the product will produce alternating expansion and contraction) to change the external environmental stress and generate thermal stress and strain in the product. Through the acceleration stress, the potential problems of the product will be exposed, such as part material problems, process problems and process problems.

Test standard: GB / T 2423.22; IEC 60068-2-14

Thermal shock test, also known as temperature shock test or high and low temperature shock test, is used to assess the adaptability of products to the sharp change of ambient temperature. It is an indispensable test in the identification test of equipment design finalization and routine test in batch production stage. In some cases, it can also be used for environmental stress screening test.

Test standard: GB / T 2423.22; IEC60068-2-14; EIA-364-32

Equipment for testing the performance of materials in various environments and testing the heat, cold, dry and moisture resistance of various materials. Constant temperature and humidity test is divided into constant damp heat test and alternating damp heat test. No matter which test is completed by constant temperature and humidity box.

Climate test: as the name suggests, the test conditions of temperature and humidity in the test are constant. Moisture mainly affects the performance of equipment through three physical phenomena: adsorption, absorption and diffusion. It is suitable for equipment stored or used in constant temperature, no condensation and high humidity environment.

Alternating damp heat test: it refers to the test method of cyclic change of humidity under the condition of maintaining high humidity in the test. The test often needs multiple cycles, which is mainly used to evaluate the influence of condensation and respiratory effect on the equipment under the condition of alternating temperature and humidity. It can be seen that the action mechanism of alternating damp heat test is obviously different from that of constant damp heat test, and the assessment purpose and influence are different.

Test standard: GB / T 2423.3; IEC60068-2-78; MIL-STD-202

Under the condition of high humidity, the alternating process of condensation and drying caused by temperature cycle is used to make the water vapor entering the sample breathe, so as to accelerate the corrosion process. When the upper limit temperature specified in GB / T 2423.4 alternating damp heat test: the temperature tolerance is ± 2%, and the relative humidity tolerance is ± 3%; The temperature tolerance at the lower limit temperature is ± 3 ℃; The relative humidity requirement is 95%.

Test standard: GB / T 2423.4; IEC60068-2-30

Temperature and humidity combined cycle test is to expose the sample to the set test environment with alternating temperature and humidity, and evaluate the changes of functional characteristics of the sample after temperature and humidity environment cycle or storage.

The product storage and working environment have a certain temperature and humidity, and will change constantly. For example, the temperature difference between day and night, the different humidity under different temperatures and different times, and the areas where the products pass through different temperatures and humidity during transportation. This alternating temperature and humidity environment will affect the performance and service life of products and accelerate the aging of products. The temperature and Humidity Cycle simulates the temperature and humidity environment in which the product is stored and works, and checks whether the impact on the product after a period of time in this environment is within the acceptable range.

Test standard: GB / T 2423.34; IEC60068-2-38; MIL-STD-202

Low pressure test is used to determine the electrical breakdown resistance of components and materials under low pressure; Determine the ability of the sealing element to withstand the pressure difference without damage; Check the influence of low air pressure on the working characteristics of components and other effects under low air pressure. Including: a) withstand low pressure environment; b) Work normally in low pressure environment; c) Withstand rapid changes in air pressure.

Test standard: GB / T 2423.21; IEC 60068-2-13

The purpose of salt spray test is to assess the salt spray corrosion resistance quality of products or metal materials. The judgment of salt spray test results is the judgment of product quality. Whether its judgment results are correct and reasonable is the key to correctly measure the salt spray corrosion resistance quality of products or metals. The judgment methods of salt spray test results include rating judgment method, weighing judgment method, corrosion occurrence judgment method and corrosion data statistical analysis method.

Test standard: GB / T 2423.17; IEC 60068-2-11; GB/T 10125

Comprehensive test refers to the test that integrates the three environmental stresses of temperature, humidity and vibration, which is used to assess the adaptability of products to transportation and use in the environment of temperature, humidity and vibration. Compared with the effect of single factor, it can more truly reflect the adaptability of electrical and electronic products to the changes of temperature, humidity and vibration compound environment in the process of transportation and actual use, and expose the defects of products. It is an indispensable important test means in the whole process of new product development, prototype test and product qualification test.

Test standard: GB / T 2423.35; GB/T 2423.36