Sunshine Sensor BF5 - Improved Design

· Measures global and diffuse radiation, and sunshine duration · PAR reference sensor for SunScan System · No moving parts, shade rings or motorised tracking · Outputs can be PAR (mmol.m-2.s-1), Energy (W.m-2) or Lux · New model includes heater as standard

The improved BF5 Sunshine Sensor is a versatile, multi-purpose solar radiation sensor. It uses an array of photodiodes with a unique computer-generated shading pattern to measure incident solar radiation. A microprocessor calculates the global and diffuse components of the radiation and determines the sunshine state. The BF5 is protected by patents EP 1012633 and US 6417500.

Two analogue voltage outputs give global and diffuse radiation, from which direct and diffuse radiation are derived. The sunshine state is represented by a digital output. The three outputs can be connected to appropriate channels on the GP1 or DL2e data loggers, or other loggers commonly used for environmental monitoring.

Improved DesignThe BF5 Sunshine Sensorhas replaced the BF3 model. Its advantages include an integrated heater as standard plus superior connectors and cabling. The heater keeps the BF5 clear of dew, ice and snow down to -20 degrees C.

Sunshine DurationThe BF5 Sunshine Sensormeasures sunshine hours indirectly using a simple equation based on both the total PAR radiation, and the ratio of total to direct PAR. This sunshine algorithm corresponds closely to the World Met Office threshold of 120 W/m-2 in the solar beam for sunshine duration. The BF5 does not need to be adjusted or repositioned to track the sun - a distinct advantage over devices with shadow rings. There are no complex electro-mechanical assemblies and no burnt paper tracks to interpret.

SunScan Canopy Analysis System
The BF5 Sunshine Sensorcan be used as an integral component of the SunScan Canopy Analysis system. The SunScan Probe is a 1 metre long light sensor array suitable for measuring PAR interception by plant canopies and estimating LAI ( Leaf Area Index). The BF5 Sunshine Sensor improves the accuracy of the SunScan system and enables it to be used even under variable light conditions.

ApplicationsIn addition to its role in the SunScan System, the BF5 Sunshine Sensor's alternative outputs enable it to be used in the study of photosynthesis, illumination and solar energy as well as in Building Energy Management Systems (BEMs).

Comparison with SPN1 Sunshine PyranometerThe SPN1 is a precision version of the BF5 Sunshine Sensor and although the two instruments have some features in common, there are important differences. These are summarised in the document: "SPN1 Sunshine Pyranometer Comparison with BF Sunshine Sensor" -please see link in theBF5 Product Comparisonsection (in left hand menu). REFERENCES: Wood J, Muneer T, Kubie J (Feb 2003), "Evaluation of a new photodiode sensor for measuring global and diffuse irradiance, and sunshine duration" Journal Solar Energy Engineering.