Emerson offers a variety of relative humidity sensors for both indoor and outdoor applications.

Available Models:

203-5751 Indoor Humidity (2%, 12VDC)
203-5153 Indoor Humidity (2%, 12VDC)
203-5754 Outdoor Humidity
203-5771 Duct Mount Humidity
210-2100 Indoor Humidity (HF534) w/o Disp or Probe
210-2102 Indoor Humidity/Dewpoint Probe

Technical Bulletins:

203-5751 Indoor Humidity (2%, 12VDC)
203-5771 Duct Mount Relative Humidity Sensor
203-5761 Outdoor Humidity Sensor