This issue is crucial, as the test results of the rain test chamber are influenced by four major factors: test parameter settings, equipment status, sample placement, and environmental conditions, which directly affect the accuracy and repeatability of the test.
1、 Differences in experimental parameter settings
Rainfall and spray pressure: Failure to calibrate rainfall according to standards (such as 10L/min for IPX3/4 and 12.5L/min for IPX5), or pressure fluctuations (commonly 0.07~0.1MPa), can result in inconsistent sample exposure intensity.
Spray angle and time: Deviation from standard requirements (such as 60 ° surround for IPX3/4, vertical spray for IPX5), or insufficient/excessive testing time, can affect the comprehensiveness of rain coverage.
Water temperature control: If the temperature difference between the water temperature and the working temperature of the sample is too large (the standard often requires 23 ℃± 5 ℃), it may cause condensation on the surface of the sample or temporary changes in material properties, which may interfere with the test results.
2、 Equipment's own status
Nozzle status: Blockage, wear, or angular deviation of the nozzle can cause uneven water spraying and water shape distortion (such as columnar water turning into scattered water), resulting in local rainfall intensity deviation.
Water circulation system: Impurities in water (unfiltered) can clog the nozzle, and insufficient water level in the tank can cause unstable pressure, affecting the continuity of spraying.
Equipment sealing: If the box leaks or external rainwater infiltrates, it will change the local rainy environment and cause distortion of test data.
3、 Sample placement and characteristics
Placement: If the sample is not located in the spray center area or is obstructed by the box structure, it may result in a non compliant wetted area.
Installation angle: If the sample installation posture is inconsistent with the actual usage state (such as the product inlet facing up/down), it will affect the rainwater infiltration path.
Sample self state: Oil stains, damaged coatings, or aging seals on the surface of the sample can alter the adhesion and penetration of rainwater, leading to test results deviating from true performance.
4、 Environmental and operational factors
Laboratory environment: Excessive fluctuations in temperature and humidity (standard requirements of 23 ℃± 5 ℃, 50% ± 20% RH) can affect the evaporation rate of rainwater and the surface condition of samples.
Operational standardization: Failure to calibrate equipment parameters before testing, failure to check sample sealing, or frequent opening of doors during testing can disrupt the stability of the testing environment.