Biral VPF-710 Visibility Sensor
High-accuracy forward scatter visibility sensor with 10m–99.99km range, immune to obstacle warning lights, window contamination monitoring, IP66, and ICAO RVR compliant. Suitable for aviation, road, marine, and industrial applications.
Description
High-Quality Visibility Measurement in a Robust, Compact Package
The VPF-710 Visibility Sensor by Senseca UK (formerly Biral) delivers high-accuracy atmospheric visibility measurement from 10m to 99.99km. Its open-design sensor head ensures free passage of air for accurate readings in all conditions, while its hard coat anodised aluminium construction provides exceptional corrosion and abrasion resistance — with many VPF series sensors still operating after 20+ years in harsh environments.
Key Features
- 10m to 99.99km Measurement Range — Covers all practical visibility conditions from dense fog to clear-sky
- Immune to Obstacle Warning Lights — Highly resistant to disturbance from aviation obstacle lights (constant and flashing), including the latest IR types
- Window Contamination Monitoring & Compensation — Maintains accuracy even as dirt builds up; two-stage warning flags prompt timely cleaning
- 45° Forward Scatter, 850nm IR Source — Optimal measurement geometry for all weather conditions including precipitation, smoke, and dust
- ICAO RVR Compliant — Meets International Civil Aviation Organisation Runway Visual Range specification; compatible with Senseca UK ALS-2 ambient light sensor for full RVR systems
- Virtually Maintenance Free — Extensive self-test monitoring; low-power optical window heaters prevent condensation
- Flexible Power Options — AC mains (120V or 240V) or low voltage DC (12V/24V); optional hood heaters for snow-prone environments
- Multiple Communications — RS232 standard; optional RS422 or RS485; ASCII encoded, polled or broadcast modes with real-time clock timestamp
- 5-Year Warranty
How It Works
The VPF-710 measures visibility using a 45° forward scatter geometry with an 850nm infrared light source. It uses 2kHz modulation of the light source combined with narrow pass-band optical filters and synchronous detection at the receiver — making it insensitive to bright or flashing ambient lights and ensuring accurate reporting even during precipitation. Visibility is output as atmospheric extinction coefficient (EXCO). The horizontal hood design eliminates surface reflection errors common in look-down geometries.
Technical Specifications
| Measurement | Visibility, EXCO (Extinction Coefficient) |
|---|---|
| Measurement Principle | Forward scatter 45° |
| Measurement Range | 10m to 99.99km |
| Measurement Error | 2% at 2,000m |
| Light Source | 850nm Infrared |
| Output | RS232 (standard); RS422 / RS485 (optional) |
| Power Supply | 12V DC, 24V DC, 120V AC or 240V AC (~6W) |
| Hood Heating | 30W (optional, for snow environments) |
| Window Heating | Fitted (low power, condensation prevention) |
| Operating Temperature | -50°C to +60°C |
| Operating Humidity | 0–100% RH |
| Protection Rating | IP66 |
| Weight (Sensor Head) | 4.9 kg (DC); 6.1 kg (AC) |
| Enclosure Material | Dip-brazed aluminium, hard coat anodised |
| Cable Length (standard) | 6m (other lengths available) |
Applications
- Aviation — airports, RVR systems, heliports
- Road transport — highway fog warning systems, tunnel monitoring
- Maritime — ports, harbours, coastal stations
- Wind energy — met mast instrumentation
- Environmental monitoring — smoke, dust, haze detection
- Rail — trackside visibility monitoring
- Military and defence
