Rotronic HF3 Humidity Transmitter for Relative Humidity, Dewpoint, and Temperature

The Rotronic HF3 is a humidity transmitter designed for fixed installation. It measures humidity and temperature, and calculates dew/frost point. It has a range of 0 to 100 %RH and -40 to 140°F (-40 to 60 °C).

The HF3 transmitter is available in a space, a duct and a wall mount version. The space mount version is used in offices and rooms where design is important. The duct and wall versions are used for HVAC applications focused on reliability and repeatability. All of these transmitters have a 2 or 2 x 2-wire or a 3/4 wire version power option.

These transmitters can be set to multiple settings and functions and can configured and enabled with the ROTRONIC HW4 software.

Key Specifications

  • Measures: humidity, temperature, dew/frost point
  • Accuracy: ±2 %RH/ ±0.3 K, at 23°C
  • Temperature limit at probe: -40° to 140°F (-40° to 60°C)/ 0 to 100 %RH; with LCD 14° to 140°F (-10° to 60°C)/ 0 to 100 %RH (models with display only)
  • Adjusted at 23°C and 10, 35, 80%RH
  • Power supply: 15 to 40 VDC or 12 to 28 VAC
  • Models with display have a backlight

Specifications, Manuals, and Supporting Literature

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Model Selection Guide

Use this table to find the right model for your application.  Don't see the option you need? Call a Lesman sales specialist at 800-953-7626

Description Catalog Number
Power/Output 2-Wire Loop Powered/10-28 VDC/4-20mA
3-Wire/15-40 VDC or 12-28 VAC/4-20mA
Mount Duct Mount (Through-Wall), Probe: 0.6" x 9.2"
Wall Mount, Visible, Probe: 0.6" x 9.2"
D_ _ _ _
W_ _ _ _
Type Humidity and Temperature
Humidity Only
_B_ _ _
_H_ _ _
Output Dewpoint or Frost Point °F
Temperature: 0° to 50° C
Temperature: 0° to 100° F
_ _MEX
_ _1XX
_ _6XX
Accessories Software, Single-User License
Service Cable, Mini-USB to USB-A Converter
Active Service Cable (Power Transmitter)
Duct Mounting Flange (max 212° F)


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