SPN1 Sunshine Pyranometer
- Global (Total) and Diffuse irradiance in W.m-2
- WMO sunshine threshold: 120 W.m-2 direct beam
- DNI (Direct Normal Irradiance) calculations
- Sunshine status
- No moving parts, shade rings or motorised tracking
The SPN1 Pyranometer is a precision solar radiation measurement instrument with a ground glass dome, and is designed for long-term outdoor exposure. It is an affordable and effective alternative to shade-ring pyranometers, pyrheliometers and traditional sunshine recorders.
The SPN1 Pyranometer is exceptionally easy to use; it needs no routine adjustment or polar alignment and works at any latitude.
An internal heater keeps the pyranometer dome clear of dew, ice and snow down to -20°C (in still air conditions), ensuring reliable readings in difficult climatic conditions. The pyranometer design is protected by patents EP 1012633 and US 6417500.
SPN1 Pyranometer Resource Centre
The Resource Centre contains a wide range of application and technical information for the SPN1 – covering DNI calculation, tilt correction, performance validation, and much more. Visit the SPN1 Resource Centre.
Direct and Diffuse Radiation
The 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. It computes direct radiation by subtracting the diffuse from the global (total) radiation.
Sunshine Duration
The WMO threshold for bright sunshine is 120 W.m-2 in a plane perpendicular to the direct solar beam. The SPN1 Pyranometer uses an algorithm based on the ratio of direct to diffuse radiation, combined with their absolute values, to estimate sunshine duration to within a few 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 assemblies and no burnt paper tracks to interpret.
Outputs and logging
The SPN1 Pyranometer provides 2 analogue voltage outputs for global and diffuse radiation, and a digital output for sunshine duration, which can be connected to data logger.
Readings can also be obtained directly from the RS232 port and viewed/logged using the SunData software supplied.
Applications
The SPN1 Pyranometer is ideally suited to multiple solar radiation measurement application areas, including PV (photovoltaic) efficiency monitoring, air pollution studies, cloud cover research, ET and heat flux studies, canopy analysis, and building energy management systems. For further information please visit the SPN1 Resource Centre.
For simultaneous outputs of total radiation, diffuse radiation and sunshine status.
|
Overall accuracy: Total (Global) and Diffuse radiation |
±5% Daily integrals ±5% ±10 W.m-2 Hourly averages ±8% ±10 W.m-2 Individual readings |
| Resolution | 0.6 W.m-2 =0.6 mV |
| Range | 0 to >2000 W.m-2 |
| Analogue output sensitivity | 1 mV=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 0-90° Zenith angle |
| Accuracy: Azimuth angle | ±5% over 360° rotation |
| Temperature coefficient | 0.02% per °C (typical) |
| Temperature range | -40 to + 70°C |
| Stability | Recalibration recommended every 2 years |
| Response time | 100 ms (typical) |
| Spectral response | 400 – 2700 nm |
| Spectral sensitivity variation | 10% (typical) |
| Non-linearity | < 1% |
| Tilt response | Negligible |
| Zero offsets |
< 3 W.m-2 for a change of 5°C/hr in ambient temperature < 3 W.m-2 dark reading |
| Latitude capability | -90° to + 90° |
| Environmental sealing | IP67 |
| Sunshine status output |
No sun=open circuit Sun=short circuit to ground |
| Power requirement |
2 mA (awake ), <30 µA (asleep) 5 V – 15 V DC |
| Heater power | 12 V – 15 VDC, up to 1.5 A |
| RS232 connector | 5-pin M12 |
| Signal output & power-in connector | 8 pin M12 |
| Mounting options | 3 x M5 tapped holes in base at 108 mm dia, 120° spacing |
| Size & Weight | 126 mm dia. x 94 mm high, 786g |
| Title | Description | Filename |
|---|---|---|
| SPN1 datasheet | SPN1_Datasheet_v6_LR.pdf |
For more information
We have been working with AMES for more than a decade and they are a reliable partner, who takes care that their equipment works flawlessly, gives professional support and is always ready to listen to the customer's wtishes when it comes to upgrades.
Bernarda Podgoršek Kovač
Manager of the environmental protection service
