Weather Resistant Tester Requirements for test time
Weather Resistant Tester, also known as temperature impact test or high and low temperature impact test, is used to assess the product on the surrounding environment, the rapid changes in the adaptability of the equipment design stereotypes of the identification test and the production stage of the routine test indispensable test, In some cases can also be used for environmental stress screening test. It can be said Weather Resistant Tester in the verification and improve the equipment adaptability of the application of the frequency of vibration and high and low temperature test.
Weather Resistant Tester can be used to test the composite material and material structure, in an instant and high temperature and very low temperature can withstand the degree of continuous environment, that is, in the shortest possible time to test its thermal expansion and contraction caused by chemical changes or Physical damage, applicable to the object, including metal, plastic, rubber, electronics and other materials, can be used as a basis for product improvement or reference.
Weather Resistant Tester in the hot and cold impact test, the test time and the starting temperature are certain requirements, the next small series for everyone to introduce.
1, test time: 1) GJB150.5 provides a lower limit of 1h, that is, the temperature stability time is less than 1h, must have 1h; if greater than 1h, then use the time greater than 1h;
2) 810F method 503.4 does not specify the specific time or optional time level, the use of products directly to the temperature stability of the time or product in the environment real exposure time.
3) GB2423.22 given 10 minutes to 3h of the five time levels, with the use of the table according to Weather Resistant Tester measured product temperature stability time, with its closest time or optional time level, directly with its closest Time as a hold time.
2, the starting temperature: Although the general hot and cold impact test standards on the hot and cold impact test start temperature is not mentioned or not mandatory, but this is the test must be considered when the problem, because it involves the test Is the end of the low temperature or high temperature state, which determines whether the need for drying the product, resulting in extended test time. If the test is finished after the low temperature standard test product is removed from the Weather Resistant Tester, it should be restored under normal test atmospheric conditions until the sample reaches the temperature stable and this operation inevitably causes condensation on the surface of the test sample The effect of temperature on the product. Thus changing the nature of the test.
In the GBJ 150 implementation guide, in order to eliminate this effect to avoid prolonged recovery to extend the test implementation time, the sample can be recovered in the 50 high temperature box, to be condensed dry and then at room temperature to achieve temperature stability. In the implementation guide it is possible to change the starting shock temperature and start the test from the low temperature so that the test results are at high temperatures to avoid the product coming out of the Weather Resistant Tester. The two test methods subject the test sample to six extreme temperatures (three high temperature, three low temperature) and five times the temperature impact process, but the number of different impact direction is different, the two tests may reach the test effect is Basically the same, but the latter method does not need to increase the drying time, shortening the Weather Resistant Tester time.
The process of humidification is to increase the water vapor pressure. The surface of the box through the proliferation of the way to the box by adding water vapor pressure to the chamber relative humidity increased, this method appeared in the fifties of last century. Because the control of the humidity at that time is mainly carried out with mercury contact surface conductive table for a simple switch adjustment, Weather Resistant Tester for the large lagging hot water tank water temperature control adaptability is poor, so the control of the transition process is longer, can not meet the alternating hot and humid The demand for more humidification requirements, more importantly, when the spray on the wall of the box, inevitably there are drops of water on the test sample to the formation of different levels of pollution. At the same time on the tank drainage is also required. So we used in the early steam humidification and shallow water dish humidification, although it controls the transition process is longer, but the system stability after the small fluctuations in humidity, suitable for constant hot and humid test. Also in the humidification process, water vapor does not increase the heat in the system.