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SPN1 Sunshine Pyranometer

Make: Delta T                                      Model: SPN1
✅ The SPN1 is exceptionally easy to use; it needs no routine adjustment or polar alignment and works at any latitude.
✅ Measurand : Global (Total) and Diffuse radiation.
✅ Sensor Type : Thermopile
✅ Signal Output :  Analog (0-2500 mV) for global and diffuse radiation and digital output for sunshine duration.
✅ Supplied With : 5m cable, Quick Start Guide and Factory test/ Calibration Certificates..

SPN1 Sunshine Pyranometer:

The Sunshine Pyranometer is a patented, meteorological-class instrument with built-in heating, designed for long-term outdoor exposure. It is an affordable alternative to shade-ring pyranometers, pyrheliometers, and traditional sunshine recorders. The SPN1 is exceptionally easy to use; it needs no routine adjustment or polar alignment and works at any latitude.

Unique Design

The Sunshine Pyranometer uses an array of seven miniature thermopile sensors and a computer-generated shading pattern to measure the direct and diffuse components of incident solar radiation. The shading pattern and thermopiles are arranged so that at least one thermopile is always fully exposed to the solar beam and at least one is fully shaded from it, regardless of the position of the sun in the sky. All seven thermopiles receive an equal amount of diffuse light. From the individual thermopile readings, a microprocessor calculates the global and diffuse horizontal irradiance, and from these values, an estimate of the sunshine state is made. The Sunshine Pyranometer is protected by patents EP 1012633 and US 6417500.

SPN1 Design Principles

The principles used in the Sunshine Pyranometer have been tried and tested in the Delta-T BF3 Sunshine Sensor. The original design has been enhanced by using miniature thermopile sensors, a high-quality ground glass dome, and an aluminum housing. The electronics have also been redesigned for higher accuracy and lower power consumption. Then SPN1 computes direct radiation by subtracting the diffuse from the global (total) radiation.


The Sunshine Pyranometer provides two analog voltage outputs for global and diffuse radiation and a digital output for the sunshine duration, which can be connected to data loggers. Readings can be obtained directly from the RS232 port.


An internal heater keeps the dome clear of dew, ice, and snow down to -20 °C (in still air conditions), ensuring reliable readings in difficult climatic conditions.

Appliocation and features of SPN1 Sunshine Pyranometer:



✅ PV monitoring
✅ Solar energy
✅ Meteorology
✅ Agronomy & plant science
✅ Architecture and building design
✅ Precision ground glass dome
✅ Wideband thermopile sensors
✅ Near ideal spectral and cosine response
✅ Standard output sensitivity
✅ Global (Total) and Diffuse irradiance in W.m-2
✅ WMO sunshine threshold: 120 W.m-2 direct beam
✅ No routine adjustment or polar alignment
✅ No moving parts, shade rings or motorised tracking
✅ Works at any latitude

Delta T



Weight (Mass)



140mm dia x 100mm (h)


Two analogue voltage outputs( 0-2500mV) for global and diffuse radiation, and a digital output for sunshine duration

Measuring range

0 to >2000 W.m-2



Power supply

2mA (excluding heater power), 5V – 15V DC


Spectral sensitivity variation: 10% typical
Analogue output sensitivity: 1mV = 1 W.m-2

Spectral range


Tilt response

Negligible errors

Spectral response


Protection Level

IP67 sealing

Complete zero off-set c)

<3 W.m-2 for a change of 5°C/hr in ambient temperature
<3 W.m-2 dark readingLowest snow & ice-free temperatures (with heating in use)

Response time (95%)

< 200ms

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