Application comparison of test methods between non-heat dissipation test samples and heat dissipation test samples After the temperature of the test sample has stabilized, when measured under free air conditions (that is, without forced air circulation), the hottest spot temperature on the surface of the test sample is higher than the surrounding atmospheric temperature by more than 5K, which is considered to be heat dissipation (see GB / T 2421-1999 4.3). For the storage test and the test sample without load specified during the test, the test uses the low temperature test method Ab, Non-heat dissipation test sample: application comparison of temperature mutation test and temperature gradient test Temperature mutation test Aa: first adjust the temperature of the low temperature test chamber (chamber) to the specified test temperature, and then place the test sample with room temperature. This is a simple and time-saving method. This test method is suitable for known temperature mutations. The case where the test sample is not damaged. Temperature gradual change test Ab: First put the test sample with room temperature into the test box (room) which is also room temperature, and then gradually cool the temperature of the test box (room) to the specified test temperature. This test method will not damage the test sample due to temperature changes. If the size of the test sample is too large, or due to the complicated functional test wiring, it cannot be placed in the low temperature test box during the mutation test. When no frosting occurs, the test Ab should also be used. Test of heat dissipation test sample with or without forced air circulation The better test method for the heat dissipation test sample is conducted without forced air circulation. If it is difficult to meet this requirement, the test Ad method can be used when the heat dissipation test sample has forced air circulation. There are two methods of forced air circulation test: Method A and Method B. Method A is used when the test chamber (chamber) is large enough without forced air circulation to meet the test requirements, but the forced low temperature environment cannot be maintained without forced air circulation in the test chamber (chamber). Method B is used when the test box (chamber) is too small to meet the test requirements without forced air circulation. Track Lighting Systems Led,Good Quality Led Downlights,Led Ceiling Strip Light Fittings Jilin Province Yuaoda Trading Co., Ltd , https://www.yuaodacn.com