Sunshine Sensor - BF3

• Measures global (total) and diffuse radiation
• Measures sunshine duration
• No moving parts, no shade rings, and no motorised tracking
• Outputs can be Energy (W.m-2), PAR (mmol.m-2.s-1), or Lux
• Designed for use with Data Loggers or the SunScan Canopy Analysis System

The BF3 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 BF3 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.

An optional heater keeps the BF3 clear of dew, ice and snow down to -20 degrees C.

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. Click here to link to abstract.

Sunshine Duration

The BF3 measures 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 BF3 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 BF3 can 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 BF3 improves the accuracy of the SunScan system by providing above-canopy reference readings.

Applications

In addition to its role in the SunScan System, the BF3's alternative outputs enable it to be used in the study of photosynthesis, illumination and solar energy.

Comparison with SPN1 Sunshine Pyranometer

The SPN1 is a precision version of the BF3 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 BF3 Sunshine Sensor" - please see link below in the Downloads and Documentation section.