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Environmental Reliability Test—Temperature Decomposition of High and Low Temperature Thermal Shock Test Chamber

There are many types of environmental reliability tests, including high temperature test, low temperature test, damp and heat alternating test, temperature and humidity combined cycle test, constant temperature and humidity test, rapid temperature change test, and thermal shock test. Next, we will break down the individual test functions for you.

1 “High temperature test: It is a reliability test that simulates the high temperature resistance of the product during storage, assembly and use. The high temperature test is also a long-term accelerated life test. The purpose of the high temperature test is to determine the adaptability and durability of storage, use, and durability of military and civilian equipment and parts stored and worked under normal temperature conditions. Confirm the performance of the material at high temperature. The scope of the main target includes electrical and electronic products, as well as their original devices, and other materials. The strictness of the test depends on the temperature of the high and low temperature and the continuous test time. High and low temperature may cause the product to overheat, affect the safety and reliability of use, or even damage;

2″ Low-temperature test: The purpose is to check whether the test piece can be stored and manipulated in a long-term low-temperature environment, and to determine the adaptability and durability of military and civilian equipment in storage and working under low-temperature conditions. Physical and chemical properties of materials at low temperatures. The standard has specifications for pre-test processing, test initial testing, sample installation, intermediate testing, post-test processing, heating speed, temperature cabinet load conditions, and the volume ratio of the test object to the temperature cabinet, etc., and the failure of the test piece under low-temperature conditions Mode: The parts and materials used in the product may be cracked, embrittled, stuck in the movable part, and changed in characteristics at low temperatures;

3，Damp-heat alternating test: including constant damp-heat test and alternating damp-heat test. High and low temperature alternating damp heat test is a necessary test item in the fields of aviation, automobiles, home appliances, scientific research, etc. It is used to test and determine the temperature environment for high temperature, low temperature, alternating humidity, and heat or constant test of electrical, electronic, and other products and materials. The changed parameters and performance. For example the temperature difference between day and night, different humidity at different temperatures and different times, and products passing through areas with different temperatures and humidity during transportation. This alternating temperature and humidity environment will affect the performance and life of the product, and accelerate the aging of the product. If it is in this environment for a long time, the product needs to have sufficient resistance to alternating heat and humidity;

4 “Temperature and humidity combined cycle test: Expose the sample to a set temperature and humidity alternate test environment to evaluate the functional characteristics of the sample after cycling or storage in the temperature and humidity environment. The storage and working environment of the product has a certain temperature and humidity, and it is constantly changing. For example the temperature difference between day and night, different humidity at different temperatures and different times, and products passing through areas with different temperatures and humidity during transportation. This alternating temperature and humidity environment will affect the performance and life of the product, and accelerate the aging of the product. The temperature and humidity cycle simulates the temperature and humidity environment of product storage and work, and checks whether the impact of the product after a period of time in this environment is within an acceptable range. Mainly for instrument and meter materials, electrical engineering, electronic products, household appliances, auto and motorcycle accessories, chemical coatings, aerospace products, and other related product parts;

5″ Constant temperature and humidity test: equipment used to test the performance of materials in various environments and test various materials for heat resistance, cold resistance, dry resistance, and humidity resistance. It is suitable for testing the quality of products such as electronics, electrical appliances, mobile phones, communications, meters, vehicles, plastic products, metals, food, chemicals, building materials, medical treatment, aerospace, etc. It can simulate high temperature, low temperature, and humid environment to test the temperature of the test product in a specific environment And humidity test. Constant temperature and humidity test can ensure that the tested product is under the same temperature and humidity environment;

6 “Rapid temperature change test: widely used in electronic and electrical, vehicle, medical, instrumentation, petrochemical and other fields, complete machines, components, packaging, materials, to evaluate the storage or work adaptability of products under temperature changes. The purpose of the qualification test is to check whether the product meets the requirements of the relevant standards; the improvement test is mainly used to assess the durability and reliability adaptability of the product under temperature change conditions, and the rapid temperature change test is used to determine the rapid change of the product at high and low temperatures The adaptability of storage, transportation, and use in a different climatic environment. The test process generally takes room temperature → low-temperature → low temperature stays → high-temperature → high temperature stays → normal temperature as a test cycle. Verify the functional characteristics of the sample after the temperature change or continuous temperature change environment, or the operational functionality in this environment. The rapid temperature change test is usually defined as the temperature change rate ≥ 3℃/min, and the transition is made between a certain high temperature and low temperature. The faster the temperature change rate, the larger the high/low-temperature range, and the longer the time, the more stringent the test. Temperature shock usually affects the parts close to the outer surface of the equipment more severely. The farther away from the outer surface, the slower the temperature change and the less obvious the effect. Transport boxes, packaging, etc. will also reduce the impact of temperature shocks on enclosed equipment. Sudden temperature changes may temporarily or long-term affect the operation of the equipment;

7“Cold and thermal shock test: mainly for electronic products, mechanical parts, and auto parts. The thermal shock test mainly verifies the conditions of use and storage of samples under rapid changes in high and low-temperature conditions. It is an appraisal test and approval test for equipment design finalization. An indispensable test in the routine test at the production stage, in some cases it can also be used for environmental stress screening test, namely high and low-temperature impact test, which exposes the test sample to a continuous alternating environment of high temperature and low temperature to make it in a short period of time. Experiencing rapid temperature changes over time, assessing the adaptability of products to rapid changes in ambient temperature is an indispensable test in the appraisal test of equipment design finalization and routine tests in the batch production stage. In some cases, it can also be used for environmental stress. Screening test. It can be said that the frequency of application of the thermal shock test chamber in verifying and improving the environmental adaptability of the equipment is second only to vibration and high and low-temperature tests.