Detecting Cloudy or Clear night

[Bashy]

Hi Brian

no m8, all mine have been in a lab flask or a light bulb, the 1st 1 i made i painted the tube black
but that one is long gone lol

[skyewright]

I recall seeing that some people have painted the probe black, though that wasn't till after I'd sealed mine up and since I've seen no condensation over quite a few months of use I'm reluctant to disturbe it without good reason  - my first (bigger sensor and bigger jar) attempt suffered a lot from condensation.

Has anyone tried painting the whole jar black?

Thoughts anyone?

Later: Maybe answering my own question - On reflection I think that painting the whole jar balck would not work because then the 'black body' would itself be exposed to the elements, instead of being in the protected environment of the jar...

[eongibier]

Bonjour,

Pour mon premier essai, sonde dans un verre noir.

Cette nuit:

Clair : 12,2°C
Très nuageux : 13°C

Serge
 

[Weather Display]

i think people could easily either create a black body device...i.e a black surface facing the sky with a temperature sensor on that surface, and then that is compared to the stations normal outside temperature reading, and the difference then determines the cloud cover
(i.e mount near your normal outdoor temp sensor)
an existing solar sensor in a jar with a blackened bottom can also then combine as a night time cloud cover sensor

i will add the ability to set the different temperture thresholds to the setup in wd...

[Weather Display]

in the latest .zip update you can now tick to use a difference in temperature between the selected extra temp sensor and the normal outdoor temp sensor
i.e a black surface with a temperature sensor on it will do the trick
or use your solar sensor in a jar, as long as it has a black bottom...

then set the thresholds, so that cloudy is the smallest temperature difference, and clear sky is the largest tempereature difference, that you see
then it should be bobs your uncle
I might have a go at setting this up myself....

[BrianM]

Hi Brian

Thanks for this, can you confirm the operation, does it work with negative numbers.

i.e. if on a cloudy night the outside temp is 15.0 deg C and the Solar Temp is 14.9 deg C but on a clear night the Solar was 13.5 deg C

What would you enter in the 2 boxes + or - and what values

cant seem to enter -0.2 only -1.something

Re Brian

[Weather Display]

for cloudy night, then, set the first number as 0, the second as 1 (i.e 0.1 colder)
for the clear night, then, set the first number as 1, the second number as 5 (i.e 1.5 colder)

[Bashy]

Hi Brian, thanks for sorting this, I am going to try this with my solar setup even though it
aint got any black on it and see how it goes, on the next mast maintenance i will be changing
my solar back to the light bulb and i will then add some black to the base of the bulb, but for
now i will see how it goes..

At the moment i can see the moon very clearly through the thin clouds my outside temp is 15.3C
and solar is 15.7C, just a little confused as to how to work out the settings that you have added

would it be 0.4 for cloudy and then wait for a proper clear night for the clear sky setting?

[BrianM]

Outside temp 16.2, clear(ish) sky earlier Solar was 15.2 (1 Deg Diff)

Now gone cloudier Ouside = 16.2 Solare now = 16.1

[Bashy]

Thats a good concise difference are the settings changing the Icon for you?

[Weather Display]

you need to have a black body to get it coming up as colder Bashy...which you do not have, so its not going to work until you do

[BrianM]

Yes Icon has changed

www.flackwellheath.net

[Weather Display]

good news then

[BrianM]

Are there degrees of cloudyness?

[Weather Display]

yes,
clear, partly cloudy, mostly cloudy, overcast