High-temperature testing is a reliability test conducted to simulate the high-temperature resistance of products during storage, assembly, and use. High-temperature testing is also the most commonly used accelerated life test. The purpose of high-temperature testing is to determine the adaptability and durability of storage and use of military and civilian equipment and parts when stored and operated under normal temperature conditions. Confirm the material's performance at high temperatures.
Application scope
The main scope of high and low temperature testing includes electrical and electronic products, their original components, and other materials. The stringency of the test depends on the high and low temperature temperatures and the duration of the test. High and low temperatures may overheat the product, affecting its safety and reliability, or even damage it, such as:

· Due to the different expansion coefficients of various materials, resulting in bonding and migration between materials

· Change material properties

· Decrease the electrical performance of components

· The elasticity or mechanical strength of the elastic element is reduced, shortening the service life of the product

· Accelerate the degradation and aging process of polymer materials and insulation materials, shortening the service life of products.

· The elasticity of flexible materials such as rubber is reduced and cracks occur;

· Increased brittleness of metals and plastics, leading to rupture or cracks;

· Make materials brittle. For example, plastics and steel are prone to brittle damage at low temperatures. The hardness of rubber materials increases and their elasticity decreases.

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method standards
Test standard reference: GB/T 2423.1, GB/T 2423.2, IEC 60068-2-1, IEC 60068-2-2, EN 60068-2-1, EN 60068-2-2, etc.
Test parameters
High temperature test: test temperature, test time, heating rate;
Performance impact
High temperature test: thermal aging, cracking, discoloration, softening, melting, expansion, or functional failure of materials;
Testing equipment and instruments

The purpose of the low-temperature test is to test whether the specimen can be stored and manipulated in a long-term low-temperature environment, and to determine the adaptability and durability of military and civilian equipment for storage and operation under low-temperature conditions. Physical and chemical properties of materials at low temperatures. The standard has regulatory requirements for pre-test treatment, initial test inspection, sample installation, intermediate inspection, post-test treatment, heating rate, temperature cabinet load conditions, and the volume ratio of the measured object to the temperature cabinet.

Failure modes of specimens under low temperature conditions: The parts and materials used in the product may crack, embrittle, have movable parts stuck, and change characteristics at low temperatures.

Effect of low temperature
1. Make the material hard and brittle;
2. The viscosity of the lubricant increases, the flow capacity decreases, and the lubrication effect decreases;
3. The performance of electronic components changes;
4. Water cooling and freezing;
5. The seal fails;
6. Material shrinkage causes mechanical structural changes.
Application scope
Low temperature testing is mainly used for scientific research, preservation of medical supplies, low temperature experiments and storage of biological products, ocean products, electronic components, chemical materials and other special materials.
method standards
GB/T2423.1-2008 "Environmental Testing of Electrical and Electronic Products Part 2: Test Method Test A: Low Temperature"
IEC 60068-2-1:2007 "Environmental Testing of Electrical and Electronic Products Part 2: Test Method Test A: Low Temperature"