Siemens QFA3173D Room Humidity and Temperature Sensor – 0–100% RH, 4–20 mA Outputs, LCD Display

General
The Siemens QFA3173D is a high-accuracy room humidity and temperature sensor from the Siemens Symaro range, designed for demanding HVAC and building automation applications. It simultaneously measures relative humidity and temperature, providing separate active 4–20 mA output signals for connection to building management systems and HVAC controllers.

Featuring an integrated LCD display, the QFA3173D allows users to view measured humidity and temperature directly at the installation point. It measures relative humidity from 0 to 100% RH and offers selectable temperature ranges of 0–50 °C, −35 to +35 °C and −40 to +70 °C.

Features
- Combined relative humidity and temperature measurement.
- Integrated LCD display for local readings.
- 0–100% RH humidity measuring range.
- ±2% RH humidity measurement accuracy.
- Separate active 4–20 mA outputs for humidity and temperature.
- Selectable temperature measurement ranges.
- Pt1000 temperature sensing element.
- Fast humidity response with a 20-second time constant.
- Temperature response time of approximately 8.5 minutes.
- IP65 housing protection.
- IP40 protection for the measuring tip.
- Replaceable measuring tip.
- Screw-terminal electrical connections.
- Suitable for demanding HVAC and building automation applications.
- Compatible with controllers accepting active 4–20 mA signals.

Key Specifications
- Brand: Siemens
- Product Family: Symaro
- Model: QFA3173D
- Manufacturer Part Number: QFA3173D
- Product Type: Room Humidity and Temperature Sensor
- Humidity Measuring Range: 0–100% RH
- Humidity Measurement Accuracy: ±2% RH
- Humidity Output Signal: Active 4–20 mA
- Humidity Time Constant: 20 seconds
- Temperature Sensing Element: Pt1000
- Temperature Measuring Ranges: 0–50 °C (factory setting), −35 to +35 °C, −40 to +70 °C
- Temperature Output Signal: Active 4–20 mA
- Temperature Measurement Accuracy: ±0.2 K at 20–26 °C; ±0.3 K at 15–35 °C; ±0.8 K at −35 to +70 °C
- Temperature Time Constant: Approximately 510 seconds (8.5 minutes)
- Power Supply: 24 V AC or 13.5–35 V DC
- Power Consumption: Maximum 1 VA
- Electrical Connection: Screw terminals
- Display: Integrated LCD
- Housing Protection: IP65
- Measuring Tip Protection: IP40
- Protection Class: Class III
- Housing Colour: Grey
- Dimensions (W × H × D): 80 × 144 × 39 mm
- Compatible Measuring Tip: AQF3151
- Warranty: 60 months (manufacturer-listed)