Hi CS members, im new to DSLR cam. i just bought a above mention dry cabinet and dunno if its working properly. the RH percentage changes quite abit like from 50% to like 65% after opening the cabinet afew times. and there is this blue light inside, must it be switched on 24hr? is it for viewing purpose? sorry for my noob questions! anyone can enlighten me? i dont quite understand the instruction manual.