[JT118]

Thanks, 700w/m2 seemed high to me, I shall get a pyranometer we have at work and see how they compare. Nothing is calibrated though they are just used for teaching but if I get similar reading from it and the Groweather then at least I will have an idea we are near the mark. I just need that rare combination of time and good weather. A rare combination up here. I have acquired an Apogee pyranometer from a police ebay auction and shall try that when I get it up from Somerset at Easter.

http://www.apogeeinstruments.co.uk/sp-11...ranometer/