If a fixed source of electric power is available, a simple solution is to=20 slightly warm the inside of the enclosure with the controller (not the=20 temp/humidity sensor). A cheap IP55 plastic container may be ok if a small lamp (0,2-0,3W?) is=20 inserted into the case because this lowers the internal RH and avoids=20 condensation on the electronics. I seen this some years ago in an=20 underground laboratory for biological studies: there were some dataloggers= =20 with this arrangement. The site was into a show cave, where humidity was=20 always near 100%RH. regards, Marco ----- Original Message -----=20 From: "V G" To: "PICLIST" Sent: Saturday, July 24, 2010 2:14 PM Subject: [EE] Preventing condensation in a 100% RH environment & other=20 issues > Hi all, > > As I have mentioned previously, I am designing a temperature and > humidity control system for my university lab that I am working in. > Several dsPIC controlled remote terminal units (RTUs) will be placed > in self contained chambers. These RTUs will provide a means to log and > control temperature and humidity. Within the chambers are special > fungi that require a high relative humidity (RH) level to grow > effectively - sometimes even close to 100% RH. > > I am concerned that water from the air may condense on the PCBs and > cause problems (such as undesirably conducting electricity, and so > on). Should I be worried about this? If so, what can I do about it? > > Also, are there any other potential problems that I should be aware of > for running home-made electronic equipment in a high humidity > environment? > > Will a crystal/crystal oscillator deviate enough from it's desirable > frequency in a high humidity environment to cause serial communication > issues? > --=20 > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist=20 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .