How to choose an outdoor atmospheric exposure field

       1) The exposure field should be set in a completely open place, which can be fully invaded by the atmosphere (air, sunlight, rain, dew, fog, frost, snow, etc.). There should be a certain distance between surrounding buildings, trees and sample racks to ensure that the shadows of surrounding buildings and trees will not be cast on the test sample at any time.



    2) Except for industrial atmospheric exposure sites, chimneys, vents, and buildings that generate a large amount of CO2, SO2 and other gases and coal ash and other pollution sources are not allowed near other atmospheric exposure sites. Failure to comply with these requirements shall be noted on the test record card.

    3) The metal frame on which the sample is placed should be coated with anti-rust paint (two layers of epoxy iron red primer and two layers of air-drying alkyd aluminum powder paint). at a 45-degree angle and facing south. Set aside the sample with a magnetic insulator.

    4) In the exposure field set in the coastal area, in order to prevent the typhoon from blowing down the sample holder, an effective fixing device should be adopted for the sample and the sample holder.

    5) When the sample is exposed to the atmosphere, various meteorological data of the exposed field should be collected or measured for analysis of the test results, including; the annual limit temperature of the region, the temperature frequency statistics table; the monthly and daily maximum and minimum average temperature and Relative humidity: rainfall and the number of rainy days, sunny days, thunder days, foggy days and sunshine days.

    6) In the process of atmospheric exposure, the harmful media in the corresponding atmosphere should be regularly analyzed according to the type of exposed atmosphere.