The high-low Temperature Test Chamber is a kind of laboratory environmental Test Chamber. When purchasing, multiple dimensional factors must be considered to select the correct equipment. You can choose according to the following five selection principles.
1. Reproducibility of environmental conditions
Environmental conditions that occur naturally in a laboratory cannot be fully replicated. However, within a certain tolerance range, people can experience very similar analog engineering products in high-low temperature, constant temperature and humidity environments. This paragraph is summarized in engineering language, that is, "The environmental conditions (including the platform environment) of the tested product generated by the test equipment shall meet the environmental conditions and tolerance requirements specified in the product test specifications." For example, according to the difference in uniformity and temperature control accuracy , the temperature chamber used for military product testing needs to meet the requirements of GJB 150.3-86 and GJB 150.4-86. This will ensure reproducibility of environmental conditions.
2. Repeatability of environmental conditions
Environmental test equipment can be used for multiple tests of the same type of product. In order to ensure the comparability of the test results of the same product under the environmental test conditions specified in the same test specification, the environmental conditions provided by the environmental test equipment need to be repeatable. That is, the stress level (such as thermal stress, vibration stress, electrical stress, etc.).
The repeatability of the environmental conditions provided by the environmental test equipment should be carried out by the verification department according to the verification standards formulated by the national technical supervision agency. For example, in addition to meeting technical indicators such as exciting force, frequency range, and load capacity, very common electrodynamic vibration tables also need to meet the requirements of accuracy indicators such as lateral vibration ratio, table acceleration uniformity, and harmonic distortion specified in the verification regulations. The use period after each verification is 2 years, and it can be put into use after passing the verification again after 2 years.
3. Can measure and control environmental condition parameters
The simulated environment provided by any environmental test equipment is observable and controllable. This is not only to limit the environmental parameters within a certain tolerance range to ensure the repeatability and reproducibility of the test conditions, but also from the safety point of view of product testing, it is also necessary to prevent the influence of uncontrolled environmental conditions. Products cause damage and bring unnecessary losses.
4. Exclude environmental test conditions
Every time an environmental or reliability test is carried out, the category, size and tolerance of environmental factors will be strictly regulated. In addition, in addition to the specified environmental conditions, it is also required that the environmental test equipment shall not be exposed to the Test products increase other environmental stress interference. For example, the ratio of the total root mean square of the surface leakage flux defined in the electronic vibratIon Meter verification rules, the signal-to-noise ratio of the acceleration and the applied speed in this frequency band.
5. Test equipment safety and reliability
Environmental testing, especially reliability testing, has a long test cycle, and the test objects are sometimes high-value military products. During the testing process, Testers usually need to perform testing work on site. Therefore, the environmental testing equipment needs to have the characteristics of safe operation, convenient operation, reliable use and long service life. In order to ensure the normal operation of the test equipment.
