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2023-03-16 0 Views

Using the test chamber for high and low temperatures

1. When conducting environmental tests in high and low temperature test chambers, you must be familiar with the required test specimen performance, the test conditions/test methods and test techniques, as well as the technical performance of the test equipment used, and you must be familiar with the structure of the device, understand it, especially the Be familiar with the operation and performance of the controller. Also, carefully read the tester's operation and use manual to avoid damage to the test pattern and incorrect test data due to abnormal operation of the tester due to operation errors.

2. Appropriate selection of test equipment for high and low temperature test chambers.
To ensure that the test runs normally, should select the appropriate test equipment according to the different conditions of the test specimens, and maintain a reasonable relationship between the test specimens and the effective volume of the test chamber.For testing the heat test specimen, its volume should not be greater than one tenth of the effective volume of the test chamber.In the case of non-heatable test samples, its volume should not exceed one-fifth of the usable volume of the test chamber. For example, if a 21 color TV is used for the temperature storage test, a test box with one cubic volume can meet the requirements of reqfill, but when it is on, it cannot meet the requirements, and a larger test box should be replaced. , as the TV must dissipate heat during operation.

3. Place the test pattern correctly.
The location of the test specimen in the high and low temperature test chamber should be more than 10 cm away from the wall of the chamber. Multiple samples should be placed on the same plane as much as possible. Samples should not block the air outlet and return air outlet, and a certain distance should be reserved for the temperature and humidity sensor. To ensure correct test temperature.

4. Using a moist heat test chamber
There are certain requirements for wet bulb gauze (wet bulb paper) used in the humidity and heat test chamber, no gauze can be substituted because the relative humidity indicator is the difference between the root distance and the temperature and humidity, strictly speaking, relates it also relates to the local atmospheric pressure at that time, it relates to the wind speed, the wet-bulb temperature indicator relates to the amount of water absorption by the gauze and evaporation from the surface These are directly related to the quality of the gauze, according to the meteorological Regulations, the wet bulb gauze must be ae special wet bulb gauze made of flax, otherwise it will be difficult to ensure the correct reading of the wet bulb thermometer, i. H. the right humidity. In addition, the placement of the wet-bulb gauze is also clearly prescribed. The length of the gauze is 100mm, and the sensor probe is tightly wound. The probe is 25-30mm away from the humidity cup, and the gauze is immersed in the cup to ensure the correctness of device control and humidity.

5. AddIn the environmental test of the medium, it should be added correctly according to the test requirements of the high and low temperature test chamber.
For example, there are certain water requirementshe used in the moist heat test chamber Distilled water or deionized water should be used for the moist heat test, and fresh water must be used, because after contact with air, water is easily polluted by carbon dioxide and dust, and water many can dissolve substances. After a long time, the specific resistance decreases. Now there is a kind of pure water on the market that is more economical and convenient, and its resistivity is equal to that of distilled water.
Application field:
The margin and Low-temperature test chamber is a commonly used experimental equipment, suitable for high-temperature and low-temperature reliability testing of industrial products, widely used in electronics and electricians, automobiles and motorcycles, aerospace. ship weapon, high school schools and other fields.