ISO 270-3:2018 pdf free
ISO 270-3:2018 pdf free.Paints and varnishes一Determination of resistance to humidity
Temperature and humidity are important parameters affecting test results. Deviations from the requirements specified can lead to results that are not comparable. However, the interested parties may agree upon alternative parameters and these parameters shall be reported.
The apparatus shall be constructed of a chamber, a water reservoir, an air supplier, a specimen rack, a temperature control device, a condensate drip pan, and others (see Figure 1). All components exposed in high humidity shall be made of corrosion- resistant materials and shall not affect the test specimen(s).
The temperature and humidity sensors shall be installed at a position where the temperature difference between the sensor and the specimens is as small as possible (±1 °C).
Care shall be taken in regard to the following:
precautions shall be taken to ensure that no condensation water is allowed to drip onto the test specimens from the walls or ceiling, nor from other test specimens;
a condensate drip pan shall catch any condensed water dripping from the test specimens.
The compressed air supplied to the chamber shall be passed through a filter to remove all traces of oil or solid. The supplied air bubbles in a water reservoir and is exhausted through the air outlet port (see Eigure 1). An air mass flow is typically about three times the chamber volume per hour.
Mount the test specimen(s) on the specimen rack as per the manufacturer’s instruction. If necessary,fill empty specimen rack slots with substitute specimens. The maximum load of the rack as per manufacturer’s instruction shall not be exceeded to ensure continuous and uniform condensation on all test specimens.
The period of test shall be as designated by the specification covering the material or product being tested. When not specified, this period shall be agreed upon by the interested parties. Testing shall not be interrupted during the prescribed test period.
At the end of the specified test period, immediately examine the test surface for signs of deterioration in accordance with the appropriate part of ISO 4628. Otherwise, evaluate to compare with the original test specimen(s).
If required, keep the specimen(s) in the standard atmosphere in accordance with ISO 3270 for the specified period and examine the test surfaces for deterioration.ISO 270-3 pdf download.
