Comparison of the main detection methods of automobile interior atomization test أداة الاختبار –

As shown in the figure, a schematic diagram of the structure of the fogging device for atomization test. The sample is placed at the bottom of the fogging glass and pressed with a pressure ring. Well, the fogging cup is placed in a constant temperature oil bath, and its upper surface is an oil and weather resistant fluoro rubber sealing ring.other temperatures. The top of the sealing ring is the mist holder (i.e. the position marked G in the figure), and the filter paper is on it. , Cooling plate. When the sample is at high temperature, the volatile substances in the material accelerate to volatilize and condense on the mist-forming medium cooled by the cooling plate on the sealing ring.

The whole test device is the same for all three test methods except for the G part in the think. For the gloss method and the haze method, the G part is a fogged glass plate, and the gloss or haze value of the glass plate before and after fogging is measured. The resultsTest results of these two methods can be obtained. For the gravimetric method, part G is an aluminum foil and the upper plane of the aluminum foil is a round glass plate with a thickness of 3 mm and a slightly larger area than the foil. aluminum. The weight of the aluminum foil before and after condensation can be used to obtain the test results of the gravimetric method.

3. Environmental Requirements

The nebulization process of the atomization test does not have high requirements on the enexternal environment, as long as the constant temperature bath and the high temperature cooling plate can be at the required temperature. Just work from home and the environment has virtually no impact on it. However, the media after nebulization (aluminum foil and glass plates) have extremely demanding environmental requirements, and small changes in the environment will have a large impact on them.

Almost all standards require that the fogged glass plate be placed in an environment with a temperature of 23°C ± 2°C and humidity of 50% ± 5% HR, and require neither wind nor sun. Some water will inevitably condense on the mist holder. The temperature and humidity ofenvironment are crucial for water evaporation. In fact, it is difficult to effectively control humidity in a general laboratory. Due to the uncertainty of environmental control, this will directly affect the accuracy of the final test results.

The three standards DIN 75201, ISO 6452 and QB/T 2728 state that during the gravimetric test, the aluminum foil is placed in a dryer for adjustment after nebulization, therefore as long as the drying is well controlled, the temperature of the environment where the device is located is sufficient and it is not necessary to take into account humidity and gas flow. The setting environment once the aluminum foil is fogged up is relatively easy to control.

4. Test Results Check

Since the atomization experiment involves many links, the operation process is tedious and is easily affected by the environment, so in order to judge whether the final experimental results are correct or not, DIN 75201, ISO 6452 and QB/T 2728 all provide the same verification method.

The gloss method is to pour 10 ± 0.1 g into the misting cup for diisodecyl phthalate (DIDP), under the test conditions of a constant temperature bath temperature of 100 °C and a temperature cooling plate temperature of 21°C. , the final test result must be within 77 ± 3%, otherwise the test will be considered failed. If successful, you must find the cause of the error and repeat the test.

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