It is an elusive thing to completely and accurately reproduce the environmental conditions existing in nature in a 　　constant temperature and humidity chamber . However, within a certain tolerance range, people's lives can accurately and approximately simulate the development conditions of the external market environment experienced by system engineering technology products in the process of use, storage, and transportation. This paragraph is summarized in engineering language. That is, "the environmental conditions (including the platform environment) of the test products generated around the test equipment should meet the environmental conditions and tolerance requirements of the product test specifications." For example, the constant temperature and humidity chamber used for military product testing, according to different types of products in High temperature, low temperature test value, test time, etc., must not only meet military standards GJB150.3-86, GJB150.4-86, but also meet the requirements of temperature field uniformity and temperature control accuracy in test specifications. Only in this way can the reproducibility of the environmental conditions in the test carried out in the enterprise environment be guaranteed.

　　The constant temperature and humidity chamber device can be used for multiple tests of the same type of product, and engineering products participating in the constant temperature and humidity chamber can also be tested on different environmental test equipment. In order to ensure the comparability of the test results of the same product in the same environment described in the constant temperature and humidity chamber specification, the environmental conditions provided by the environmental test equipment need to be repeatable. That is to say, the stress development level (such as thermal stress, vibration stress, electrical stress, etc.) imposed by the environmental test technology equipment on the tested product is consistent with the requirements of the same test design specification.

　　The repeatability of the environmental conditions provided by the constant temperature and humidity chamber equipment is guaranteed by the national metrology and verification department after verification according to the verification regulations formulated by the national technical supervision agency. Therefore, it is necessary to develop test equipment that requires the enterprise environment to meet the requirements of various information technology capability indicators and accuracy indicators in the verification regulations, and the use of different time shall not exceed the time limit specified in the verification cycle.

　　The environmental development conditions provided by any social and environmental factor test technology equipment need to be managed and observed and controlled. This is not only for the enterprise to limit the environmental design parameters within a certain tolerance range, but also to ensure the reproducibility and reliability of the test research conditions. Repeatability, and it is necessary from the safety of product testing to prevent out-of-control damage to the tested product due to the analysis of environmental and economic conditions, and cause some unnecessary losses. In various test specifications, the general requirement for parameter test accuracy is not less than one-third of the allowable error of test conditions.

　　Every time a reliability test is carried out, there are strict regulations on the category, quantity and tolerance of the environment or environmental factors, unless the test requires environmental factors to penetrate side by side, so that the product failure and failure mode can be judged and analyzed at the end of the test or at the end of the test, Provides an accurate basis, so it is required to stipulate in the environmental test equipment that in addition to providing environmental conditions, no other environmental stress interference is allowed on the product under test. Such as platform magnetic flux leakage, acceleration signal-to-noise ratio, total root-mean-square ratio of in-band and out-of-band velocities, etc. are stipulated in the electric vibration table verification regulations. The tests of accuracy indicators such as random signals and harmonic distortion are all verification items designed to ensure the conditionality of environmental tests.