Night-Time Cloud Sensor - 1-Wire Project - Revisited

[TokKiwi]

Underneath the plate is a thick rubber washer/gasket and that adds another level of insulation.  However, there will be a thermal conductivity transfer through the mounting bolts to the steel bracket underneath.  I should find slightly longer ones and use fiber washers for some insulation as well.  However, the design does have a slight drawback in that there is a parcel of air above the plate that will dampen down the sensitivity but so far that does not appear to be the case.  It does seem fairly sensitive and follows conditions pretty faithfully. 

So apart from the smaller "delta T" I am getting, I am pleased as it was an easy installation and the materials were common and readily available.

Graeme

[niko]

I think you would have a much better delta T if you had a separate plate in the "jar" with insulation between it and the base plate. As it is now I don't see that there is much jar effect at all but that's just my opinion 

[Weather Display]

I am getting a bit confused here

seems to be 2 projects?
a temp sensor in a jar for solar?
and the night time sensor?

with the night time sensor, the black body needs to be sheilded from the ground...thats one thing that is important

[TokKiwi]

The solar sensor was a pingpong ball in a jar to start with - the normal solar sensor from Hobby-Boards, then it was converted to a webcam weather dome enclosure.  

It is essential to use a similar board as the solar sensor, a humidity, or a temperature board would do as they all have the side connections for additional temperature sensors.  I had the solar sensor already and added the "nighttime cloud sensor" into the same board to get it into my 1-Wire network.

They both provide sky conditions so it is likely people want to do both as I have done.  Others with some Davis or OS stations etc, can have additional external sensors too from the manufacturer, but La Crosse don't so I had to use the Hobby-Boards route.

with the night time sensor, the black body needs to be sheilded from the ground...thats one thing that is important

And as I described above, this does have a rubber mounting washer that acts as a weather seal and a thermal barrier from objects from below.  I also painted the bottom of the plate white, and could have used a silver paint instead.

Graeme

[thac]

Hi guys, I thought I would share my success with my cloud sensor. Instead of using super glue, I used some thermal epoxy I had left over from other projects.

Here is a link: http://arcticsilver.com/arctic_silver_thermal_adhesive.htm

I largest delta I could achieve was 5 degrees on a clear night.

[Weather Display]

5 degrees F or 5 degrees C ? 

[thac]

Hahaha, I forgot 5 Degrees F. I guess that would make a difference.

[edhall]

Hi all,

Is there a ideal height to mount one? My first one is also weather worn and I'm building a new one. The first was mounted about 12' high; but, I have a way to mount it at about 5 foot with a clear view of the sky. Think this will work?

Thanks,

Ed

[TokKiwi]

Yes Ed that should work - just so long as the view to the sky is unhindered.  My first trial unit was more efficient than my second but it was not as UV resistant and hence broke down inside 12 months. The second one as depicted had a smaller plate and a diffracted view of the sky.  But it works and that is all I needed!   Windy has made it variable and adjustable for our different devices, and the sky condition at night is sent to my WU page faithfully.

[edhall]

Thanks. In this area it's hard to find a light like you found; but, I found one that will act as a housing. I've got the plate resting on about 2 in. of styrofoam. The housing is a heavy plastic. We'll see if it works over the weekend.

Ed

[meteofrog]

Hi all,

a really interesting project.
Does anybody have an idea/experience in using with an Davis VP wireless?
(because I am not an engeneer....  )

[TokKiwi]

Meteofrog - it needs an extra usb port to be used to bring in signals from a Hobby Board style of network.  In itself for the nighttime cloud sensor, it is just a temperature sensor but it includes a Rom ID and the software with WD analyses a whole series of these specific sensors on what could be a complete weather station in itself. The individual components, temperature, humidity windspeed and direction all connect to the same network CAT5 cable normally with jumper cables - each device has two CAT5 LAN Network style ports, In and Out.  But all you need is a single temperature sensor 5mm by 3mm and a sealed soldered connection to a CAT5 cable, the other end at your computer, where there is an adaptor from Cat5  into a RJ12 plugging into the adaptor from HB  to usb.  You can buy the simple cable crimping tool and do it all yourself.  I can expand on this in more detail later, just at home before heading to work.  But it also gives you a chance to establish a grass temperature or something else as well

TK

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