Just thought I'd let you know :- I am a development engineer at Michell instruments (www.michell.co.uk). Most of the newer products on this site are my own design. (Takes a bow) It was nice to see our web site as part of a discussion on this list. You may think this is salesman woffle, but Michell Instruments IS the world leader in moisture measurement and generation. DONT go anywhere else for your moisture applications. Look out for a product called TRANSMET (stands for TRANSmitter METeorlogical). This is our hottest seller. 3-wire dewpoint transmitter capable of humidity measurement down to -100 degC dewpoint (1 part of water per billion parts of air) and up to +20 degC dewpoint. 1 degC dewpoint accuracy !!. 4-20mA / 0-20mA output over the range. Also RS232 output and RS485 networkable. Guess who designed this ? (hee hee) (Dont forget to mention my name to our sales guys and tell them where you saw the advert !!) Regards, Darren