On 27/05/2021 23:27, T i m wrote:

snip


I'm not trying to actually 'measure' anything (although the sorts of
levels are interesting if they are correct and when compared with the
stated light output levels of domestic lighting) but to just get the
comparable levels that could be useful to automate what might equal
'it's a bit dark outside, better turn the light on', or enable the
'turning on a light on in the hall automatically with a PIR during an
overcast day and before sunset' ... sort of thing. ;-)


For that purpose I think you can safely forget about losses from
anything that starts off looking clear and is stable. The odd 20% is
neither here nor there. The difference in illuminance between direct
sunlight and an overcast day is around a factor 100. It's another
factor 10 or so down to a typical living room at night.

JOOI does the home automation software have built-in facility to ignore
short-term changes so e.g. the headlights of a car arriving don't turn
off the lights on the stairs?

--
Robin
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