I should be able to enlighten or shed some light into your puzzle.
let me tell you, your dry cabinet is not VERY air tight seal. How do i know? I gotten 2 dry cabinet so far, 1st was digicab 36(sold) and now a DHC-80. I notice the humidity lvl in my cabinet rise and drop every now and then. so i check the seal of the cabinet and found interesting things. (how i check? I shine a torch light from inside the cabinet along the joint seam and where the air gaps are,
the light shine thru)
1. the top of the cabinet is spot welded and thus dont provide a all round complete seal (AKA air gaps for leaking or incoming air)
2. thou the door got rubber seal and magnetic hold, the magnet hold might not be enough, best to lock the key lock. (bend the key lock
metal inside a bit more to give it a tighter lock, it helps improve the door seal)
my old AD-36 solution to improve the seal, buy a roll of duct-tape and tape round the joint at the top of the cabinet, tape the area at the door also but on the inside.
my current DHC-80 solution, buy silicon and apply it along the joints inside the cabinet to seal up the air gaps.
