"Nick Gardner" wrote in message
news
On 22/04/2018 18:30, Keith Harris wrote: The Met Office might take some
convincing as to the 'accuracy' of the BL as I believe the KZ recorder
uses the same method as the R&D, i.e., the difference between sunlight and
shadow.

I prefer to keep it simple, if there's a sharp-edged, distinct shadow then
then the sun is shining.

--
Nick Gardner
Otter Valley, Devon
20 m amsl
http://www.ottervalleyweather.me.uk


I don't think that the KZ rcorder uses the same method as the R&D, Nick. The
latter uses a shadow post to generate a difference in output from a ring of
photo-diodes. The KZ uses '3 photo-diodes with specially designed diffusers
the determine when a threshold of 120 W per sq m is exceeded'
See also:
measuringtheweather.com/wp-content/uploads/2012/06/An-overview-of-sunshine-recorders-July-2012.pdf
by Stephen Burt.


--
Bernard Burton

Satellite images and weather data for Wokingham at:
www.woksat.info/wwp.html



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