High and low temperature test is the abbreviation of high temperature test and low temperature test, and the purpose of the test is to evaluate the impact of high and low temperature conditions on the performance of equipment during storage and operation. The test conditions, implementation, and steps of high and low temperature tests are detailed in GJB 150.3A-2009 "Equipment Laboratory Environmental Test Methods High Temperature Test" and GJB 150.4A-2009 "Equipment Laboratory Environmental Test Methods Low Temperature Test". High and low temperature testing, also known as high and low temperature cycling testing, is a part of product environmental reliability testing.  Basically, all products are stored or operated in a certain temperature. In some environments, the temperature will constantly change, from high to low. For example, in some areas with large temperature differences during the day and night. Or the product may repeatedly enter or exit high-temperature or low-temperature areas during transportation, storage, and operation. This type of high and low temperature environment may reach temperatures above 70 ° C or even higher at high temperatures, and temperatures below -20 ° C or even lower at low temperatures.

This constantly changing temperature environment can affect the functionality, performance, quality, and lifespan of products, accelerate their aging, and shorten their lifespan. If the product is exposed to such high and low temperature environments with significant alternating changes for a long time, it needs to have sufficient resistance to high and low temperature cycling. In this way, we need to simulate certain environmental conditions and conduct high and low temperature tests on the product to understand its performance in this area. If the test results do not meet the standards we set, we need to improve the product based on the test results, and then retest until it meets the standards.

Salt spray test is carried out in the salt spray test chamber, which is generally used to test the corrosion resistance of metal or the corrosion resistance of metal surface after electroplating. Corrosion test can be carried out by spray of corrosive salt solution, and can also be carried out by corrosive gas. Different corrosion methods can be used according to the specific use environment.

When conducting salt spray tests, there is basically a set of test standards and rating judgments for the tests. The determination of corrosion in salt spray testing is mainly based on four methods: rating determination, weighing determination, determination of the appearance of corrosive substances, and statistical analysis of corrosion data.

The statistical analysis method for corrosion data provides a method for designing corrosion tests, analyzing corrosion data, and determining the confidence level of corrosion data. It is mainly used for analyzing and statistical corrosion conditions, rather than specifically for quality judgment of a specific product.