6.3.1 Description of 24 h cycle6.3.1.1 Description of' temperaturelhumidity sub-cycle (applicable to all cycles, see Figures 2a and 2b)At "zero time" of every 24 h cycle, the chamber condition shall be controlled to a temperature of 25 f 2 "Cand relative humidity of 93 & 3%.a) The temperature of the chamber shall be continuously raised to 65 f 2 "C in a period of between 1.5and 2.5 h.During this period, the relative humidity shall remain within the limits 93 it 3%.b) The temperature and relative humidity in the chamber shall be maintained at 65 i 2 "C and 93 f 3%respectively until 5.5 h after the start of the cycle.c) The temperature shall then be allowed to fall to 25 & 2 "C in a period of between 1.5 h and 2.5 h.During this period, the relative humidity shall remain within the limits 80% to 96%.d) Beginning 8 h. after the start of the cycle, the temperature shall again be continuously raised to 65 it 2 "Cin a period of between 1.5 h and 2.5 h.During this period, the relative humidity shall be 93 f 3%.e) The temperature and relative humidity in the chamber shall be maintained at 65 f 2 "C and 93 & 3%respectively until 13.5 h after the start of the cycle.f) The temperature shall then be allowed to fall to 25 f 2 "C in a period of between 1.5 h and 2.5 h.During this period, the relative humidity in the chamber shall remain within the limits 80% to 96%.g ) The chamber shall then continue to run at a stabilised temperature of 25 & 2 "C and relative humidity of93 4 3% until the start of the cold sub-cycle or until the end of the 24 h cycle as appropriate.