Visibility sensor VS20k

Summary
VS20k is a precision visibility sensor measuring meteorological optical range up to 20 km (20,700 m), providing continuous visibility data for traffic management, road safety and infrastructure monitoring. A calibration device is available as an option.

Overview
The VS20k measures visibility up to 20,700 m and is supplied in variants including the VS20k-UMB. The VS20k-UMB can be configured with the UMB Config Tool to read/change configuration, perform calibration, poll current measurements and load/store configurations. Measurement outputs follow the Lufft UMB protocol for integration with supervisory systems.

Unique features

• Active Spider Defense (ASD): integrated vibrating motor activates at irregular intervals to limit spider build-up and reduce maintenance frequency.
• First and only visibility sensor with Active Spider Defense for reduced downtime.
• Open, free-to-use UMB communication protocol (ASCII-2.0) for straightforward integration.

Technical Attributes (table)

• Measurement range: 10 m – 20,700 m
• Temperature range: -40 to +60 °C
• Storage temperature: -40 to +70 °C
• Interfaces: RS485 (2-wire, half duplex); Analogue output 4–20 mA
• Sensor ports: ASD (Active Spider Defense)
• Resolution: 1 m; averaging 60 s, 10 min
• Relative humidity: 0–100% RH
• Dimensions: 500 × 230 × 80 mm
• Protection rating: IP66
• Protocol: UMB, ASCII-2.0
• Power supply: 20–30 VDC (typical 24 VDC)
• Accuracy: ±10%
• Weight: ~4 kg (without bracket); ~5.6 kg (with bracket)

Benefits

• Provides reliable long-range visibility measurements to support motorway, highway and bridge safety systems.
• Reduced maintenance interventions due to ASD anti-spider vibrating motor.
• Flexible integration options via standard UMB protocol and analogue outputs for SCADA and traffic control systems.

Notes on configuration and data
The VS20k-UMB is configurable with the UMB Config Tool: read/change configuration, perform calibration, poll live measurement values and load/store configuration files. Measurement output conforms to the Lufft UMB protocol for downstream processing.

Technical specifications

• Measurement Range EU: 10 m - 20,000 m (32 ft - 65,616 ft)
• Temperature range: -40 - +60 °C (-40 - +140 °F)
• Standard storage temperature: -40 - +70 °C (-40 - +158 °F)
• Interface: RS485 (2-wire, half duplex); Analogue output (4 - 20 mA)
• Sensor Ports: ASD (Active Spider Defense)
• Resolution EU: 1 m, 60 s, 10 min
• Relative humidity: 0 - 100 % RH
• Dimensions: 500 x 230 x 80 mm (19.7 x 9.1 x 3.1 in)
• Protocol: UMB, ASCII-2.0
• Power supply: 20 - 30 VDC; typical 24 VDC
• Compliance: Class III (SELV) CE
• Weight: ~4 kg (without mounting bracket); ~5.6 kg (with mounting bracket)
• Operating humidity: 0 - 100 % RH (non condensing)
• Casing IP Rating: IP66
• Accuracy: ±10 %