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Intelligent Active Road Sensor ARS31Pro-UMB

The active road sensor ARS31Pro detects freezing point temperatures independently from de-icing materials and has a two-part housing for easy maintenance

The active ARS31Pro-UMB sensor is flush-mounted in the road or runway surface and measures the freezing temperature by means of active cooling and heating of the sensor surface. through this, it's independent from the de-icing material. In addition, it measures the road surface temperature. This surface temperature sensor is integrated into a second housing which is connected to the ARS31Pro-UMB. The distance between the two housings is 50 cm. One additional measurement is carried out to find out critical conditions in the next few hours. This early alert message delivers extra road surface condition information in addition to the real time road conditions. The two-section housing design allows the combined electronics unit to be removed for maintenance purposes at any time, in just a few minutes. In conjunction with the interface converter 8160.UISO, the sensor can be built into new and existing UMB networks. The sensors are addressable and can be networked.

  • road surface temperature, freezing point
  • active cooling and heating (Peltier element), NTC (road surface temp.)
  • Two part housing design allows easy maintenance/re-calibration, low energy consumption allows solar operation, freezing point determined independently from de-icing material
  • RS485
  • 8810.U051
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  • Replaceable sensor/electronics
  • Simulation of critical surface conditions in the avery near future
  • All-in-one sensor including active measurement of freeze point temperature
  • Mixture-independent measurement
  • Analog outputs in combination with 8160.UDAC
  • For winter maintenance operators as part of road weather stations on roads, motorways, highways (municipalities, federal states and provinces)
  • For smart cities
  • For airports, installed on runway as important part of the IDS (ice detection system) and water film height detection (aqua-planing risk)
Firmware - Lufft - ARS31/ARS31Pro-UMB
Version 11.0
Manual - Lufft-ARS31 ARS31Pro (EN)
Road Weather Maintenance Checklist
Road Weather Maintenance Checklist
Software - Lufft - ConfigTool .NET
Version 1.6
Software - UMB Config Tool
Whitepaper - Road Weather Selection Guide
The Whole World of Road Weather Monitoring
Video - IRS31Pro/ARS31Pro: Installation of Lufft Road Sensors IRS31Pro and ARS31
Video - Lufft: a passion for precision (Corporate Video)
Video - ViewMondo Tutorial: The Management Software for Road Weather Stations
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Dimensions Ø 120mm, height 50mm
Weight Approx. 1100g
Storage temperature -40...70°C (in packaging)
Protection type IP68
Power supply 24 VDC ±10%
Connector CAGE CLAMP, WAGO, (cross-section <0.5mm²)
Operating temperature -40...80°C
Operating rel. humidity 0...100% RH
Power consumption Approx. 30 W
Interface RS485, baud rate: 2,400...38,400 bit/s (default: 19,200),
Cable length 50m
External road surface temperature
Principle NTC
Measuring range -40 ... 80 °C
Unit °C
Accuracy ±0.2°C (-10...10°C), or ±0.5°
Resolution 0.1
Freezing point
Measuring range -40 ... 0 °C
Unit °C
Accuracy > -15°C ±0,5°C for Tg > -15°C (with NaCI, determined according to CEN/TS 15518-4);
Accuracy < -15°C ±1,5°C for Tg < -15°C (with NaCI, determined according to CEN/TS 15518-4)
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IRS31Pro/ARS31Pro: How to install a Lufft Road Sensor?

In this Training Video, our service technician Jim Latimer explains, how to install Lufft Road Sensors.

To the Training Video: Installation of Lufft Road Sensors