The SPN1 Sunshine Pyranometer is a 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 SPN1 is protected by patents EP 1012633 and US 6417500.
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.