VPF-750 Visibility & Present Weather Sensor


The VPF-750 Visibility and Present Weather sensor is the most advanced in Biral’s product range. Its enhanced performance allows the reporting of freezing precipitation in addition to the weather codes typically available from a forward scatter sensor.

The sensor is designed for use in aviation applications where extended weather information, including past weather, is required for inclusion in METAR reports. The sensor is also well suited to research applications and use in meteorological observation networks. The unique backscatter receiver combined with accurate external temperature, humidity and precipitation sensors gives the VPF-750 unparalleled abilities in distinguishing frozen from liquid precipitation, with the added advantage of identifying freezing precipitation. The sensor reports both WMO table 4680 and METAR codes to simplify integration in to host systems. A wealth of other data is provided including a transmissometer equivalent EXCO.

An optional interface to the ALS-2 Ambient Light Sensor simplifies use in aviation applications where both Runway Visual Range (RVR) and METAR information is required.

  • 47 WMO Table 4680 present weather codes
  • Reports freezing precipitation
  • Designed for aviation, research and general met use
  • Reliable measurement in all weather conditions
  • Highly corrosion resistant hard coat anodised finish with 5 year warranty
  • Window contamination monitoring and compensation
  • Unaffected by obstacle warning or other lights
  • Easy integration of Biral ALS-2 Ambient Light Sensor
  • DC powered
  • 10m to 99.99km measurement range
  • This product is certified for use in Russia by Rosstandart – the Federal Agency for Technical Regulation and Metrology.
  • This product is certified for use in China by the Civil Aviation Administration of China (CAAC).


  • Measures: (MOR & EXCO)
  • Visibility and Present Weather
  • Output Serial data
  • Range (visibility) 10m to 99.99km
  • Measurement Error
  • ≤1.3% at 600m
  • ≤1.8% at 1,500m
  • ≤2.0% at 2km,
  • ≤8.3% at 15km,
  • ≤10.5% at 30km
  • ≤20.0% at 75km
  • Measurement principle: Forward scatter meter with 39° to 51°; centred at 45°
  • Precipitation detection resolution
  • Rain: 0.015 mm/hr (0.0006 in/hr)
  • Snow: 0.0015 mm/hr (0.00006 in/hr)
  • Maximum rain rate ~500 mm/hr (20 in/hr)
  • Rain intensity accuracy ≤10%


  • Output rate (seconds) 10 to 300 (selectable)
  • Serial outputs RS232 or RS485
  • Present Weather 50 WMO Table 4680 codes, including Past Weather, Freezing Rain and Ice Pellets
  • 45 METAR codes
  • Humidity Sensor Capacitive type. 0 – 100% RH
  • Air Temperature Sensor PT 100 type. -30°C to +70°C


  • Sensor Power 19 to 28Vdc
  • Heating power As sensor supply
  • Maximum Power 72W


  • Window heaters Fitted as standard
  • Window contamination monitoring Fitted as standard on all the sensor windows
  • Hood heaters Optional


  • Operating temperature -50°C to +60°C
  • Operating humidity 0 – 100% RH
  • Protection rating IP66


  • CE Certified
  • EMC compliance with EN61326-1997, 1998, 2001
  • RoHS and WEEE compliant


  • Material Hard coat anodised aluminium
  • Weight (including external sensors) 7.4kg
  • Length 751mm
  • Warranty 5 years
  • Lifetime >10 years
  • MTBF (MIL-HDBK-217F) 6.5 years (56,700 hours); MTBF (Service return calculation >35 years


  • Self-test capability As standard
  • User confidence check 6 months recommended
  • Window Cleaning Automatic compensation and warnings
  • Field calibration With optional calibration kit


The sensor is delivered in sturdy recyclable foam filled packaging with:

  • 6m power and data cable
  • Pole mounting kit (2 x U-bolt)
  • User manual and calibration certificates


  • PW.CODE User defined precipitation definitions.
  • Per definition set
  • 70.CAL VPF Series Calibrator
  • 70.CASE VPF Series Transit Case
  • 70.SK VPF Series Spares Kit
  • 75.WTY 1 Year extended warranty