Sunlight Probe Delta-T BF5 Sunshine Pyranometer

„Delta-T Devices Ltd. BF5 Sunlight Probe Sensor Pyranometer

• Measurements: Total and diffuse radiation (Wm-2), DNI calculations, sunlight status
• WMO sunlight limit: 120 Wm-2 for direct radiant flux
• Outputs: Analog signals for global and diffuse radiation, digital output for sunlight duration
• Features: No moving parts, shadow rings or motorized tracking system

Delta-T SPN1 Pyranometer Features and Description

The SPN1 Pyranometer is a precision solar radiation measuring instrument with a glass dome for long-term outdoor use. It is an affordable and effective alternative to shadow ring pyranometers, pyrheliotrometers and traditional sunlight observers.

The SPN1 Pyranometer is extremely easy to use; it requires no periodic adjustments or polar pointing, and it works at any latitude.

An internal heater maintains the pyranometer dome at temperatures down to -20°C (in still weather), ensuring reliable readings in challenging climatic conditions.

SPN1 Pyranometer Resource Center

The Resource Center provides a variety of application and technical information about SPN1 – including DNI calculations, deviation correction, performance validation, and more. Visit the SPN1 Resource Center.

Direct and Diffuse Radiation

The pyranometer uses an array of seven miniature thermocouple sensors and a computer-generated shadow ring structure to measure the direct and diffuse components of solar radiation. It calculates the direct radiation by subtracting the diffuse radiation from the total radiation.

Sunlight Duration

The Light Year Organization limit for light is 120 Wm-2 in direct solar irradiance. The SPN1 Pyranometer uses an algorithm based on the ratio of direct and diffuse irradiance, together with their absolute values, to estimate the duration of sunlight, achieving only a few tens of percent of the WMO standard.

The SPN1 Pyranometer 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 devices and no need to interpret burnt paper tracks.

Outputs and Recording

The SPN1 Pyranometer provides 2 analog input signals for global and diffuse radiation, and a digital output for sunlight duration, which can be connected to data loggers such as the Delta-T Devices GP2 and the compact GP1.

Results can also be obtained directly from the RS232 port and viewed/recorded using the supplied SunData software.

The Delta-T Devices GP1 Data Logger is a powerful, all-in-one data logging device that provides an economical solution to the SPN1 Pyranometer.

Adaptation

The SPN1 Pyranometer is ideal for a variety of solar radiation measurement applications, including photovoltaic (PV) efficiency monitoring, air pollution studies, cloud cover studies, ET and heat flux studies, hemp analysis, and building energy management systems. For more information, visit the SPN1 Resource Center.

SPN1 Pyranometer Evaluation for Solar Optical Thickness Measurement

Prof. Victor Estelle's solar radiation research group at the University of Valencia is using the SPN1 Pyranometer together with the Cimel and Prede sun photometers to see how it compares to these higher-precision but more complex instruments. Their results show a relatively good agreement - scientific posters were presented at Skynet Rome 2016 and EGU Vienna 2016.

Direct-Normal Irradiance (DNI) calculation

Direct-Normal Irradiance (DNI) is the amount of solar radiation reaching the Earth's surface perpendicular to the direction of the sun's rays per unit time. It is particularly useful when comparing the efficiency of solar modules with DNI, especially in field tests. The output from the SPN1 Pyranometer allows the calculation of DNI in sun-tracking, horizontal and inclined installations.

There are two ways to calculate DNI:

1. DNI software: The SPN1 Pyranometer can calculate DNI (requires firmware version 1.08 or later). Results are only available on the serial output port and require RS232 commands and results to be retrieved using a terminal application or similar. For more information, please download the document „Using the SPN1 Firmware DNI Function“. To update the SPN1 firmware to the required version 1.08, please contact techsupport@delta-T.co.uk
2. DNI calculator: You can download an Excel add-in to calculate DNI from the output of a horizontally mounted SPN1 Pyranometer using data recorded from the analog or serial output. Download the spreadsheet here.

Note: The scientific literature sometimes refers to the SPN1 Pyranometer as the SPN1 Radiometer.

Sunlight Sensors – Delta-T device group

More information: on the manufacturer's website or send us an inquiry!