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Using the HSS VF-500 visibility sensor in marine applications
lighthouses, harbors, bridges, buoys,ships, offshore industries,
wind energy sites,oil / gas platforms, remote locations

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Fog / Visibility Section
 
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  • Do you need to automatically activate fog horns, operational warning devices and navigation equipment in poor visibility?

  • Do you need a system which operates continuously, accurately and reliably for many years with minimal maintenance?

  • Are you considering unmanning or downsizing platforms and have navigational and safety issues?

  • By automating the activation of equipment will it save on costs or improve safety?

 

        If yes this page should interest you. . .


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Go to the HSS VF-500 product page for more information


Proven track record 

The HSS VF-500 is a cost-effective reliable solution and has been used for over 20 years in marine applications throughout the world for switching fog horns and lights. The HSS VF-500 Visibility Sensor continuously monitors the atmospheric extinction coefficient, and thus visibility, in all weather conditions.

With rugged construction and durable finish the VF-500 sensor will operate problem-free for many years requiring minimal maintenance and is built to withstand severe environmental conditions.

A true test of quality and reliability is the fact that Biral HSS sensors were the first forward scatter visibility sensors on the market and have an established track record especially for use in the marine environment. With proven reliability and accuracy they are the sensors of choice in many offshore and coastal applications and are used extensively on lighthouses around European and US coastlines to switch fog horns.


How does the sensor switch equipment on and off?

The sensor features a fog-alert capability which automatically switches external equipment such as an audible or visual alarm or warning light whenever fog, rain, smoke or dust lowers the visibility to a predetermined value.

For example, the system can be set so that when the visibility drops below 1.5 nautical miles for more than 5 minutes (to avoid errors that would be encountered from a passing ship’s exhaust) the circuit closes and allows an alarm to signal.

Of course, the settings for the visibility range and time delays for both the on and off conditions of the alarm are user selectable and once set require no further intervention, thus providing a reliable, accurate and automated cost-effective system.


Why it is suited to the marine environment

The HSS VF-500 sensor is designed for many years of trouble free service in the marine environment. A robust, waterproof housing covers the electronics with neoprene O-rings used to provide watertight seals. The sensor unit has an ingress protection rating of better than IP66 and all components that are exposed to weather are salt-dip brazed and made of hard anodized aluminum. This provides long life, extreme accuracy and repeatability together with unparalleled corrosion protection in harsh environments. The anodizing is especially effective in asaltwater environment.

The sensor has several features designed to prevent measurement problems or malfunctions due to severe environmental conditions. These include the design and construction of the viewing windows, the selection of industrial and military grade electronic components that withstand environmental extremes and the optional de-icer hood heaters for operation in temperatures as low as -58oF.


What are the servicing and maintenance reuqirements

The maintenance requirements for the HSS VF-500 are minimal with only periodic wiping of the windows necessary to remove any contaminants.


What spare parts are required

The HSS sensors are extremely reliable with a MTBF (Mean Time Between Failure) of at least 8 years and an infra-red light-source with a life expectancy exceeding 10 years. Indeed many sensors have been in trouble-free operation for over 20 years.


Installing the sensor

Siting and installation is simple and requires only basic electrical skills and a simple tool-kit. The low mass of the sensor allows for one man installation and removes the need for bulkymounting masts. Being a forward scatter sensor it is far easier to site and not prone to the interference that back-scatter sensors experience. The HSS VF-500 consists of a sensor head which makes the measurements and a control box which houses the electronics. The sensor head and control box can be installed up to 65 ft apart for safe and convenient access (sensor head to measure accurately and control box to be convenient to service personnel).


What are the power requirements

The sensor has very low power consumption and can be mains or battery operated. It is ideal for use with solar power and therefore suitable for operation at remote locations and on unmanned platforms.


What is the warranty period

All HSS sensors come with 2 years warranty as standard, are assembled to rigorous ISO 9000 accredited quality standards and can be customised to suit your specific application if required.

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Benefits of buying an HSS fog / visibility sensor

As with all the sensors in the HSS visibility sensor range there are a number of benefits which have been proven over many years of operation:

Long-Term Reliability

The Biral HSS sensors are designed to withstand years of abuse problem free and are the best choice for long life expectancy. For two decades customers such as the Dutch Motorway Authorities have been using HSS sensors and they are still enjoying the reliability and durability of the sensors (most have run the entire time without a single problem!). The US Military also continues to uses Biral HSS sensors in land and maritime roles.

Extensive Trial History

As Biral HSS sensors were the first sensors on the market, we have an extensive library of independent test results comparing the HSS brand against the competition. Not only do the reports show excellent performance but also Biral can show the consistency of the sensors’ performance since their conception in 1984. The sensors have been used by nearly every national weather service, several defence organizations, aviation authorities, offshore oil platforms, numerous lighthouse authorities and institutes carrying out meteorological research. Indeed, in the past, we have even sold to our competitors!

References and test reports are available on request.

Lightweight and Low-Powered

Biral HSS sensors are some of the lightest around and can easily be installed by a single person. They are also designed for very low power consumption, allowing additional flexibility for a wider range of applications.

HSS Sensors were developed two decades ago and were the first Forward Scatter Meters (FSM) to use an infra-red light-source, they have remained ahead of the competition ever since. There are three models available, all offering:

Corrosion-Free

Corrosion is not an issue with HSS sensors due to the fact that we only use hardanodized aluminium combined with a salt-dip brazing process. The dip brazing ensures that the sensor enclosures are strong and leak-free while the military standard anodizing provides unrivalled corrosion resistance. The extra expense of this process has proven worthwhile for strength, accuracy and long-term durability. Performance and quality are paramount and only the best results are accepted.

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Unbeatable Accuracy

The combination of design, light-source type, wavelength and undisturbed sample volume gives Biral HSS sensors unbeatable accuracy.

Design

Using a unique patented design, the HSS range is considered to provide the best correlation of extinction coefficient (EXCO) to observed visibility. In reduced visibility conditions, whereas other sensors using different scattering angles report only precipitation, Biral HSS sensors continue to provide accurate visibility AND precipitation data.

Light-Source

The light-source is an infra-red diode which has been proven to provide higher accuracy, longer life and much more consistent readings than sensors using visible light-sources. The patented design of the HSS sensors means that no other sensor can match their performance.

Wavelength

Biral’s choice of light-source and wavelength (880 nm) is considered to be the best for accuracy where it counts most - around the 1 mile range. The choice of the wavelength is critical when deciding how the sensor performs in terms of accuracy and shifts in light spectra. The wavelength used is perfect for the shift in light from white (visibility below 1 mile) to blue (visibility from 1 mile to several miles). Almost all sensors using FSM technology can detect the white spectrum well, but HSS Sensors also detect the shift from white to blue spectrum and therefore maintain accuracy values to much higher visibility ranges.

Undisturbed Sample Volume

Accurate visibility and precipitation measurements require the sample volume to see only what is actually present. Other designs often suffer from precipitation splashing off the instrument enclosure, turbulence effects and unwanted reflections. The unique design of Biral HSS sensors ensures that the sample volume remains undisturbed regardless of wind direction and precipitation conditions.

Optical Geometry

Reflections from snow and surface water may cause measurement errors if they are allowed to enter the receiver, a common problem in some sensor designs. The sensor heads of all Biral HSS sensors are positioned in the horizontal plane to ensure that the measurements are not influenced by surface reflections. Biral HSS sensors also provide "no-dew window heaters" and optional hood heaters to ensure that the heads remain free from mist and obstruction even in the most challenging blowing snow conditions.


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Links to previous pages
+ USA / Canada met index
      

 

Fog / Visibility Section
 
     + Fog Index 
                          

 

If you would like more information please contact the Met Team or

Go to the HSS VF-500 product page for more information

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