Environmental testing instruments are a general term for instruments used to monitor various parameters of indoor and outdoor environments.

Selection guide:

1. Basic principles for selecting environmental testing equipment

1) Reproducibility of environmental conditions

2) Repeatability of environmental conditions

3) Measurability of environmental condition parameters

4) Exclusivity of environmental test conditions

5) Safety and reliability of testing equipment

2. Reproducibility of environmental conditions

It is unattainable to fully reproduce the environmental conditions that exist in nature in the laboratory. However, within a certain tolerance range, people can accurately and approximately simulate the external environmental conditions experienced by engineering products during use, storage, transportation, and other processes.

3. Repeatability of environmental conditions

An environmental testing equipment may be used for multiple tests of the same type of product, and a tested engineering product may also be tested in different environmental testing equipment. In order to ensure the comparability of the test results of the same product under the environmental testing conditions specified in the same testing specification, it is necessary to require the environmental conditions provided by the environmental testing equipment to be repeatable.

4. Measurability of environmental condition parameters

The environmental conditions provided by any environmental testing equipment must be observable and controllable. This is not only to limit the environmental parameters within a certain tolerance range, ensure the reproducibility and repeatability of the test conditions, but also from the perspective of product testing safety, in order to prevent the loss of control of environmental conditions that may cause damage to the tested product and result in unnecessary losses. At present, various test specifications generally require that the accuracy of parameter testing should not be less than one-third of the error allowed by the test conditions.

5. Exclusivity of environmental test conditions

Each environmental or reliability test conducted by environmental testing equipment has strict regulations on the category, magnitude, and tolerance of environmental factors, and excludes the infiltration of non test required environmental factors, so as to provide accurate basis for judging and analyzing product failure and failure modes during or after the test. Therefore, environmental testing equipment is required to provide not only the specified environmental conditions, but also, It is not allowed to add other environmental stress interference to the tested product. As specified in the verification regulations for electric vibration tables, the table leakage magnetic field, acceleration signal-to-noise ratio, and the ratio of the total root mean square values of the acceleration within and outside the band are limited. The inspection of random signals and accuracy indicators such as harmonic distortion are all calibration items developed to ensure the consistency of environmental test conditions.

6. Safety and reliability of testing equipment

Environmental testing, especially reliability testing, has a long testing cycle and sometimes targets high-value military products. During the testing process, testers often need to operate and inspect or test around the site. Therefore, it is required that environmental testing equipment must have characteristics such as safe operation, convenient operation, reliable use, and long working life to ensure the normal progress of the test itself.