The HF4 transmitter series is designed for fixed installation in HVAC and light industrial applications where a high measurement accuracy is required within the range of 0 to 100 %RH and -50 to 100°C (-58 to 212°F). The key features of the HF4 will satisfy application requirements ranging from the most basic to demanding.



The HF4 transmitter is available in different configurations and has an extensive set of settings and functions that can be configured and enabled by the user with the ROTRONIC HW4 software.

In spite of its sophistication, the HF4 can still be used just as a simple conventional humidity and temperature transmitter. Whether you decide or not to take advantage of its full potential, the HF4 will let you have it your way.

Key Features

► Measures relative humidity and temperature, or humidity only, or temperature only

► Calculates the dew or frost point

► Integral probe - cannot be separated from transmitter. Duct (through-wall probe) and wall configurations

► Operating limits at probe 0 to 100 %RH and -50 to 100°C (-58 to 212°F) - except wall mount models.

► Accuracy at 23 °C: ± 1.0 %RH and ± 0.2 °C

► 2-wire, loop-powered and 3-wire models

► Supply voltage: 10 to 28 VDC (2-wire models) or 15 to 40 VDC / 12 to 28 VAC (3-wire models)

► Optional LC display and keypad

► Analog output signals or digital interface

► Digital interface allows the simultaneous reading of relative humidity, temperature and calculated parameter

► Configurable analog output signals (signal type, parameter and range)

► Digital interface offers several communication protocol options, including a ModBus compatible protocol

► Automatic RH sensor test with optional sensor drift correction

► Configurable fail safe mode - fixed output signals in the event of a humidity or temperature sensor failure

► Simulator function (fixed output signals) for on-site validation of the measurement loop

► Full access to the settings and functions via external service connector or via optional digital interface