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Damp Heat Cycling

This test is used to evaluate the aptitude of the relay for operation and storage at high relative humidity combined with cyclical temperature changes where, generally, dew forms on the surface of the test piece.

To perform this test, the test piece is placed in a test chamber where it is subjected to temperatures cycling between 25 °C and the specified upper air temperature at high relative humidity.

The test severity is defined by:
  • the upper air temperature (40 °C or 55 °C),
  • the number of temperature cycles (e.g. 6 cycles).
This test is performed according to the IEC 68-2-30, Db test.

Note: In this standard there are two variants given that differ from one another only in the phase of the drop in temperature: Variant 2 permits greater deviation with reference to the relative humidity and the speed of the temperature changes than variant 1.