Condensation phenomenon and condensation test requirements of small high and low temperature test chamber
Source: website release time: 2020-07-29 14:30:00 reading: 118
Small high and low temperature test chamber The main test of the product is to test the performance of the product through the test of the low temperature, humidity and thermal expansion by using the low temperature, humidity and environmental effects.
small high and low temperature test chamber can also carry out constant temperature and humidity test, keep the test environment temperature at a certain required temperature and humidity, and can carry out high temperature aging test or low temperature test, so it is also called constant temperature and humidity test chamber. It can be used to simulate multi climate environment, and it is often used in aerospace, chemical, pharmaceutical, metal, plastic, rubber, ceramics, composite materials and so on.
Small high and low temperature test chamber The condensation phenomenon is as follows
condensation is actually a phenomenon of water molecules adsorbing on the product, but it is generated when the test temperature changes. In the heating stage, when the surface temperature of the product is lower than the dew point temperature of the surrounding air, the water vapor will condense on the surface of the product to form water droplets. In the heating stage of the alternating damp heat test, due to the thermal inertia of the product, its temperature rise lags behind the test The temperature of the box. Therefore, the amount of condensation on the surface depends on the heat capacity of the product itself, the heating rate and the relative humidity in the heating stage. In the cooling stage of the alternating damp heat test, the inner wall of the closed shell cools faster than the air in the shell, so the condensation phenomenon also appears.
Small high and low temperature test chamber Condensation test requirements of
components shall be subjected to condensation test after removing the shell. During the condensation test, the circuit board should be in live operation. The electronic functions are monitored by a computer supported test bench. The test piece shall be placed in the center of the test chamber. The ambient temperature of the PCB under test was always 1K to 2K higher. Because when the humidity is from 98% to 98%, there will be continuous condensation on the test piece. The parameters of dewing control are the start temperature and the end temperature, as well as the time of 10 ° C and 80 ° C for two important temperature data.
condensation test method:
condensation test can be completed in a climate box with condensation function. During the condensation test, due to the air flow, the test piece should be placed in the center of the test chamber, and the temperature control of the climate test chamber should be turned off. The temperature of the laboratory is increased by controlling the temperature of the water bath. The total temperature difference of the test chamber is less than that of the test chamber. The density of condensation film on the test piece depends on the relative humidity in the test room and the gradient of water bath temperature. Only distilled water is allowed for dewing test.