Rotronic HF3A Humidity and Temperature Transmitter
The Rotronic HF3A is a versatile transmitter designed for measuring relative humidity and temperature, offering advanced features and flexible application possibilities.
Key Features and Advantages
The HF3A transmitter boasts a robust, industrial-grade PC-ABS housing (IP65) available in wall-mount, duct-mount, and cable-mount versions. It features a clear display with a trend indicator, status LED, and backlight. The device offers two freely selectable and scalable analog outputs, with options for 2-wire (HF3A-2), 3/4-wire analog (HF3A-3), and digital (HF3A-D) signals. The HF3A-D model also supports RS485 communication.
Advantages:
- Versatile design to meet diverse application needs.
- Accurate measurement of relative humidity and temperature with additional psychrometric calculations.
- Freely programmable outputs and scaling via NFC interface, including NFC support without power.
Applications
The HF3A is suitable for a wide range of applications, including:
- HVAC systems for buildings, offices, and storage halls.
- Museums and libraries where aesthetics are important.
- Climate monitoring for greenhouses and swimming pools.
- Light industrial manufacturing, including electronics, packaging, and small-scale assembly lines.
Technical Specifications
| Feature | HF3A-2 (2-wire) | HF3A-3 / HF3A-D (3-/4-wire) |
|---|---|---|
| Sensor | Humidity and temperature, fixed sensor | |
| Accuracy at 23 °C | ±1.2 %RH, ±0.1 °C | ±1.2 %RH, ±0.1 °C |
| Initialization Time | Typically 5 seconds | Typically 5 seconds |
| Measurement Interval | 1 second | 1 second |
| Measurement Range | 0%RH to 100%RH | 0%RH to 100%RH |
| Application Range (Temperature) | Wall-mount: -40 °C to 85 °C / -10 °C to 60 °C Duct/Cable: -50 °C to 100 °C |
Wall-mount: -40 °C to 85 °C / -10 °C to 60 °C Duct/Cable: -50 °C to 100 °C |
| Application Range (Humidity) | 0%RH to 100%RH (non-condensing) | 0%RH to 100%RH (non-condensing) |
| Display Indicator | Yes (resolution up to 2 decimal places, with backlight and status LED) | Yes (resolution up to 2 decimal places, with backlight and status LED) |
| Analog Output Signals | 4 mA to 20 mA | Freely scalable: 0-1 V, 0-5 V, 0-10 V, 0-20 mA, 4-20 mA |
| Analog Output Resolution | >15 Bit | >15 Bit |
| Digital Output Signal | N/A | RS-485 on screw terminal (for HF3A-D) |
| Cable Connections | 1 x M12 screw terminal | 2 x M12 for HF3A-D |
| Psychrometric Calculations | Yes | Yes |
| Power Supply | 2-wire: 10 VDC to 28 VDC | 3-/4-wire: 18 VDC to 36 VDC |
| Current Consumption | 2 x 23 mA | < 50 mA |
| Load per Analog Output | Max. 500 Ω | Max. 500 Ω |
| Humidity Sensor | ROTRONIC Hygromer® HT-1 | |
| Temperature Sensor | Pt100 1/3 Class B | |
| Interface | UART, NFC and USB | |
| Software | HygroSoft | |
| Housing Material | PC-ABS | |
| Dimensions | Wall-mount: 122 x 172 x 40.5 mm Duct: 122 x 82 x 265.5 mm Cable (housing only): 122 x 82 x 40.5 mm (sensor only): 144 x 15 mm |
Wall-mount: 122 x 172 x 40.5 mm Duct: 122 x 82 x 265.5 mm Cable (housing only): 122 x 82 x 40.5 mm (sensor only): 144 x 15 mm |
| Weight | Wall-mount: 204 g Duct: 226 g Cable: 332 g |
Wall-mount: 204 g Duct: 226 g Cable: 332 g |
| IP Protection | IP65 | |
| Solder Material | Lead-free (RoHS 2011/65/EU directive) | |
| Norms | CE Conformity 2014/30/EU | |
| Conformity | GAMP5 | |
Sensor Accuracy Graphs
The following graphs illustrate the temperature and humidity sensor accuracy for different HF3A models and mounting types:
HF3A Conduit/Cable vs. HF3A Wall-mount Humidity Accuracy:
A graph showing the deviation in %RH against temperature (°C). The HF3A Conduit/Cable shows a tighter tolerance band compared to the HF3A Wall-mount, especially at lower and higher temperatures.
HF3A Conduit/Cable vs. HF3A Wall-mount Temperature Accuracy:
A graph showing the deviation in °C/K against temperature (°C). Both models show a similar temperature accuracy profile, with deviations generally within ±0.5 °C.
Accessories
The Hygroflex Advanced transmitters are compatible with the HygroSoft software. An NFC-USB reader is available for configuring the device via a mobile phone or computer.
