yes, but they don’t show cloud height, or cloud cover at nightime 
Maybe we could if we could easily read the text without the awful background. Don’t people realise that backgrounds like that don’t help legibility!
That would be great - I am also searching for a long time for somethingn like that ! 
Could anybody let me have more informations for that neat instrument? How much is it
Thanks
so true… atleast the text wasn’t blue!
Check these links out for homebrew models.
http://www.tass-survey.org/tass/technotes/tn0093.html
http://www.noao.edu/staff/gillespie/projects/cloud-detector.html
just a note, would it not be the case the temperature sensor in a jar (solar sensor) with the bottom painted black, then also becomes a black body at night, and so the colder its temperature compared the normal station temperature, at night, the clearer the sky is ???
I’ve often wondered whether the solar sensor jar should be painted completely black. However, even if it was fully painted black, would there be enough difference in black body temperature between cloudy and non-cloudy nights to spot the difference? I know that’s the way that the homebrew sensor works, but I wondered if the sensor in that case was able to measure much smaller differences in temp (I’m not familiar with peltier sensors…are they like peltier coolers?)
I’d have to dig my college books out to work out black body radiation…although back then we were doing calcs about measuring things that were significantly hotter than a cloud at night, so maybe the formulae would be different!
I have noticed on clear nights that the temp in the jam jar sensor is several degrees lower than on cloudy nights but not sure to the extent it varies.
The difference is most noticeable on clear still nights.
It’s one and the same. Very simply the peltier cooler is like a bunch of thermocouples, apply current to it and you get a temp differential between the two sides, apply a temp differential and it works just like a regular thermocouple and generates current.
Good references, esp the first one
thats good to know its actualy working that way leo
maybe an exagerated black body/temperature sensor in a jar could be simply used to determine cloud cover at night?
Why should a solar sensor jar not be totally black anyway? It’s trying to measure solar radiation and black bodies are the best absorbers/radiators.
Here at Whitby Weather at 2.00 am there is an average breeze of 8kph, I estimate about 50% cloud
cover & a temp in the solar sensor 3.4 C less than my outdoor temp sensor.
Oh by the way I use pickle jars & don’t bother to paint the lid or anything else Black–works OK for
me when I don’t have a com port problem
Here’s another device, http://www.atnf.csiro.au/pasa/15_3/clay/paper/node2.html that uses a sensitive infra red detector [color=red][b]TPS 534[/b] [/color]that’s available from www.newark.com for $19. If you search google for “TPS 534” there are a number of different implementations of this design.
anyone gone further on this topic ??
Cyclone
I somehow missed this thread… I’m very keen to try the peltier as I have a couple lying around and some styrofoam, foil, heatsink etc… be interesting to plot the potential under different sky conditions
I think the big advantage of the peltier as a cheap IR sky sensor is that it it intrinsically differential so no need to compensate for anbient temps etc…
keep us informed ricky
I’ve bought all the components I need to build a device with two IR sensors (one pointing up for sky temp and one down for ambient). I just need to find time to build/test something now.
Any news on this project ?
Also i notice a clear night and cloudy night icon in my folders how does WD work out the icon, drop in temperature rate ?
I'm very keen to try the peltier
I have recently bought a peltier element and intend to try to make a cloud sensor using it (linking it to a LabJack). I intend to base it on the info given on http://www.astro.uni-bonn.de/~kbagschi/cloud.shtml There is more detailed information on the web but I have lost the URL.