As Emily has commented, tests have been running throughout the day. The morning started bright with blue skies and some thin cirrus cloud, but as the morning progressed a weather front moved in from the south bringing in rain and total cloud cover.
06:2UTC – Thick cloud now fully obscuring the sky
16:15UTC – The cloud cover now thinner but still 8/8ths coverage here.
The results so far have however been useful. We have a good range of data from the sensor tests under overcast conditions. (results will follow). The forecast for tomorrow is brighter, so I hope to run a few additional tests under clear sky conditions at 12:00UTC to get a maximum brightness reading, and if conditions permit Emily will take some further clear sky sunset and dusk readings to add to the data.