The Sunshine Pyranometer is a patented, meteorological class instrument, with built-in heater, 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.

The Sunshine Pyranometer provides 2 analogue voltage outputs for global and diffuse radiation, and a digital output for sunshine duration, which can be connected to data loggers, such as the Delta-T DL2e and GP1. Readings can also be obtained directly from the RS-232 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.



  • Global (Total) and Diffuse irradiance in W.m-2
  • No routine adjustment or polar alignment
  • No moving parts, shade rings or motorized tracking
  • Works at any latitude
  • Precision ground glass dome
  • Wideband thermopile sensors
  • WMO sunshine threshold: 120 W.m-2 direct beam
  • Near ideal spectral and cosine response
  • Standard output sensitivity
WMo Classification Matches "WMO Good Quality Pyranometer" classification
Overall Accuracy: Global (Total) and Diffuse Radiation

±5% Daily Integrals

±5% ±10 W.m-2 Hourly Averages

±8% ±10W.m-2 Individual Readings

Accuracy figures give 95% confidence limits, i.e. 95% of individual readings will be within stated limits under normal climatic conditions.

Resolution 0.6 W.m-2 = 0.6 mV
Range 0 to >2000 W.m-2
Analogue Output Sensitivity 1mV = 1 W.m-2
Analogue Output Range 0-2500 mV
Sunshine Status Threshold 120 W.m-2 in the direct beam
Accuracy: Sunshine Status ±10% sun hours with respect to the threshold
Accuracy: Cosine Correction ±2% of incoming radiation over 0-90º Zenith angle
Accuracy: Azimuth Angle ±5% over 360º rotation
Temp Coeffifient ±0.02% per º C typical
Temperature Range -20 to +70º C
Recalibration / Stability Factory recalibration recommended every 2 years.
Response Time < 200 ms
Spectral Response 400-2700 nm
Spectral Sensitivity Variation 10% typical
Non-Linearity < 1%
Tilt Response Negligible errors
Zero Offsets

<3 W.m-2 for a change of 5º C/hr in ambient temperature

<3 W.m-2 dark reading

Latitude Capibility -90º to +90º
Environmental IP67 sealing
Sunshine Status Output

No sun = open circuit

Sun = short circuit to ground

Power Requirement 2 mA (excluding heater power), 5V - 15 V DC
Heater Power 12 V - 15 V DC, up to 1.5 A
Heater Control Continuously variable up to 2 0W output for external temperatures below 0ºC
Lowest Snow and Ice-Free Temperatures (with heater in use)

-20º C at 0 m/s wind speed

-10º C at 2 m/s wind speed

Mounting Options 3 x M5 tappe dholes in base: 108 mm pcd, 120º spacing
Size and Weight 140 mm dia x 100 mm (h), 940 g