[KenGee (Kenith Gee)]

Alex, I will get around to writing it up one day, in the mean time I made from a peltier device and USB kit from various description on the net.
http://www.noao.edu/staff/gillespie/...-detector.html
http://www.atnf.csiro.au/pasa/15_3/clay/paper/node2.html
I'm a programmer so I wrote the interface and control program myself. If your into that it's not that hard, the main issue is getting the calibration correct. It works by measuring the difference in the radiation from the sky and the ground, when there are cloud the grounds radiation is reflected back. This needs to be offset against the air temperature as well. I be using it for 5 months and it works well. I have it alert me when I go to sleep if the clouds roll in. I will get it to close the observatory in the near future.