WM33 & 52 Wall Mount Relative Humidity and Temperature Transmitter

The WM33 & 52 are wall-mounted units that have the ability to display and provide an output signal of %RH, dew point or absolute humidity and temperature. The WM Series offers excellent measurement accuracy and stability wherever a wall-mounted sensor is required.

Product Features

  • WM33 is designed for low cost HVAC applications
  • WM52 has digital technology and is designed for accurate measurements in a controlled environment
  • Easy to re-calibrate to maintain high accuracy
WM33 & 52



Technical Specification

Measurement Range (RH) 0-100% RH
Measurement Range (T) -20 to +80°C
Accuracy at 23°C
WM52: <±2% RH (10–90% RH)
WM33: <±3% RH (30–80% RH)
Accuracy at 23°C
WM52: ±0.2°C
WM33: ±0.3°C
Stability - RH Sensor <±1% RH/year
Response Time - RH Sensor <10 sec typical without filter (for 90% of the step change)
Electrical output/input
Output Signal 4–20 mA, 0–1, 0–5, 0–10 V
Supply Voltage 14–30 V DC (for 0-5 / 0-10 V output)
5–30 V DC (for 0–1 V & 4-20 mA output)
Operating conditions
Operating temperature
    Probe, Housing

-30 to +85°C (-22 to +185°F)
-40 to +85°C (-40 to +185°F)
Measurement Range Pt100/1000: -50 to +200°C
Accuracy Pt100/1000: ±0.15%
Mechanical specification
Housing Material White moulded polymer
Weight 82g
Electrical Connections Screw terminals
Alternative outputs
Dew Point -40 to +60°C
Absolute Humidity 0 – 200 g/m3