Omega Engineering's ETF012 electronic hygrotherm
ETF012 series electronic hygrotherm senses the ambient temperature and relative humidity in an enclosure with electrical/electronic components and turns on a heater (or alternatively, a fan) at either set point, helping prevent the formation of condensation in the enclosure. The LED integrated in the adjustment knob on the active controller is lit when the connected device is in operation. CE compliant, the hygrotherm is equipped for 35mm DIN rail mounting.
Omega Engineering; 203/359-1660; www.omega.com