I too would be interested to know by what principle electronic humidity guages work and how accurate/consistent/reliable they are. Even better, if there are any inexpensive ?hygrostats (devices for switching on at low humidity and off at high). I am told that there are cheap ones used in air-con systems. The only ones I have seen for greenhouses are over #100 in uk. John Stanley
_______________________________________________ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids

