


Rotronic HF4 Series Humidity and Temperature Transmitter
Rotronic HygroFlex4 HF4 – Wall & Duct Mount Humidity & Temperature Transmitter
High-accuracy transmitter (<1% RH / 0.2 K) with AirChip3000, dew point, auto-diagnostics, and scalable analog/digital outputs for HVAC and industrial monitoring.
The Rotronic HygroFlex4 HF4 Series is a universal HVAC humidity & temperature transmitter with AirChip3000 digital technology, delivering <1% RH and 0.2 K accuracy. Available in wall-mount (HF42/HF43/HF45) and duct-mount (HF42D/HF43D/HF45D) versions, it supports scalable analog outputs, dew point calculation, 2000-point data logging, auto-diagnostics, and optional digital communication (USB/Ethernet/RS485).
KEY FEATURES
Accuracy at 23°C: ±1% RH / ±0.2 K
Hygromer® IN-1 humidity sensor
RH / Temperature / Dew-Point output
Scalable analog outputs: 0–1 V, 0–5 V, 0–10 V, 0/4–20 mA
AirChip3000: auto-diagnostics, 2000-point memory, sensor correction
Integrated RH/T probe (wall & duct)
Fast response t63 < 10 s
IP65 protection, robust industrial ABS housing
Optional digital outputs: USB, RS485, Ethernet (LAN/WLAN)
TECHNICAL SPECIFICATIONS
| Specification | Value |
|---|---|
| RH Range | 0–100% RH |
| Temperature Range | –50…100°C measurement / –40…60°C electronics |
| Accuracy | ±1% RH / ±0.2 K at 23°C |
| Response Time | <10 seconds (t63) |
| Outputs | 0–1 V, 0–5 V, 0–10 V, 0/4–20 mA |
| Digital Options | USB, Ethernet, RS485 |
| Supply Voltage | HF42: 20–28 VDC; HF43/HF45: 18–40 VDC or 13–28 VAC |
| IP Rating | IP65 |
| Data Logging | Internal 2000-point memory |
| Weight | ~220 g |
APPLICATIONS
HVAC & AHU monitoring
Ventilation ducts
Cleanrooms, labs, pharma
Museums, archives, storage
Industrial climate control
WHAT’S IN THE BOX
HF4 wall or duct transmitter
Filter & mounting hardware
Wiring guide
FAQ
Q1: What is the accuracy?
±1% RH and ±0.2 K.
Q2: Does HF4 calculate dew point?
Yes.
Q3: What outputs are available?
0–1 V, 0–5 V, 0–10 V, 0/4–20 mA, plus optional digital.
Q4: Is the HF4 suitable for industrial HVAC?
Yes—IP65 housing and fast response.