Temperature and Humidity Test/Reliability Test /CNAS/Cma/Third-Party Testing Agency

3. Temperature and humidity test:

Temperature and humidity test is divided into: constant damp and heat, alternating damp and heat, damp and heat cycle, condensation test, frost test. The physical phenomenon of humidity is condensation, adsorption, absorption, diffusion, and respiration. The effect of air humidity on product failure is obvious. If humidity is too high, which will cause metal corrosion machine damage and reduce electrical insulation performance. In the production process of precision machinery, measuring instruments, electronic equipment and other products, the humidity discomfort will also seriously affect the quality of products. Humidity is too low, some products will produce dry crack, static electricity, will also affect the quality and performance. In storage, transportation and use, the product is always affected by the humidity combined with the temperature. The higher the temperature, the faster the insulation moisture speed under the same humidity, the temperature decreases, easy to form frost and ice, accelerate the deterioration of the material.

Selection of test method:
damp and heat test is one of the product three proof (moisture proof, mildew, salt spray) test, which is widely used in the field of electronic and electrical technology. In order to get the most economical, easy to control and good reproducibility test results, it is very important to choose the test method correctly.
(1) Select the damp and heat test method according to the moisture absorption mechanism and moisture absorption mode of the product. The constant moisture and heat test; If the product is strengthened by condensation or respiration, the alternating damp and heat test; If the product has penetration effect and no respiration, the product type and use conditions.
(2) Select according to the characteristics of the product itself. For solid products or insulating materials, in order to check the electrical performance or insulation performance of these products in the humid atmosphere, constant damp heat test is usually used. If moisture is caused by condensation, alternating damp heat test should be used. For sealed or hollow products, due to the action of thermal stress caused by thermal expansion and cold contraction of the product moisture, alternating damp heat test is often used.
(3) Select according to the reproducibility of the test results. According to the experience of international and domestic environmental engineering, for some products, the effect of constant heat and humidity and alternating heat and humidity test is consistent on the base wood. In this case, because the constant damp heat test is simple, economical and good reproducibility, the constant damp heat test should be used.