Three new samples (lenses) shall be subjected to five cycles of temperature and humidity (RH = relative humidity) change in accordance with the following programme:
(a)    3 hours at 40 °C ± 2 °C and 85-95 per cent RH;
(b)    1 hour at 23 °C ± 5 °C and 60-75 per cent RH;
(c)    15 hours at –30 °C ± 2 °C;
(d)    1 hour at 23 °C ± 5 °C and 60-75 per cent RH;
(e)    3 hours at 80 °C ± 2 °C;
(f)    1 hour at 23 °C ± 5 °C and 60-75 per cent RH;
Before this test, the samples shall be kept at 23 °C ± 5 °C and 60-75 per cent RH for at least four hours.
Note:    The periods of one hour at 23 °C ± 5 °C shall include the periods of transition from one temperature to another which are needed in order to avoid thermal shock effects.
 

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