The sunshine recorder has been built in-house, it is designed to record how much sunshine has been captured during each day. The device has an analogue clock which displays how much sun we have received, and a output for a EL-USB-5 Counter, Event and State USB Data Logger ,giving you an accurate account of the duration of sunlight each day. It is a very versatile mobile unit intended to be used in a variety of areas. I will put more details on the website once I have completed 12 months of testing. This instrument could also be converted for a USB port and a one wire weather station add-on.
The Campbell–Stokes recorder (sometimes called a Stokes sphere) is a kind of sunshine recorder. It was invented by John Francis Campbell in 1853 and modified in 1879 by Sir George Gabriel Stokes. The original design by Campbell consisted of a glass sphere set into a wooden bowl with the sun burning a trace on the bowl. Stokes's refinement was to make the housing out of metal and to have a card holder set behind the sphere.
The unit is designed to record the hours of bright sunshine which will burn a hole through the card.