Weighing ~0.2 kg (7.1 oz), Omega Engineering’s ETF012 Series electronic hygrotherms sense the ambient temperature and relative humidity in an enclosure with electrical/electronic components. The instrument turns on a heater or a fan at either set point to help prevent the formation of condensation in the enclosure. The LED integrated in the adjustment knob on the active controller shines when the connected device is in operation. The CE-compliant units are equipped for 35 mm DIN rail mounting. Pricing starts at $90.