The Setra SRH Outdoor Air humidity transmitter is built specifically for mounting outside, where the sensor is exposed to rain, dust, and temperature swings that a wall or duct unit would never see. It uses a durable capacitive sensor rated for 0-99% full-scale RH measurement, and it recovers cleanly even after being saturated at 100% RH, which matters a lot for outdoor air intakes that go through humid mornings or wet weather.
In actual application, this unit can be ordered with either an active (analog) temperature output or a passive RTD/thermistor output, so you get two measurements – humidity and temperature – from one device. The humidity accuracy comes in 2%, 3%, or 5% RH options depending on how tight you need the reading, and the analog output can be 4-20mA or user-selectable 0-5Vdc/0-10Vdc. The housing is a polycarbonate UL94V-0, NEMA4 enclosure, so it holds up well outdoors.
From our experience, one of the more practical features here is the replaceable sensor tip. If the sensor drifts or gets contaminated after a few years outside, you just swap the tip – no special training needed, and no field calibration required since each replacement tip is factory calibrated before it ships. That’s a real time saver on maintenance rounds. It also comes with a 5-year warranty on the electronics and a 2-year warranty on the sensor module.
Before we quote this, we would normally check the accuracy class you need, whether you want active or passive temperature output, and the analog output type your BMS expects. Hope this helps.
