Detecting Cloudy or Clear night

[41South]

Oh dear, Looks like rain does hinder the performance of this sensor

Its the 1st time i have had rain since making the cloud sensor and outside
temp is 12 and cloud sensor is 11.3, so the rain on the glass is causing it to drop
for some unknown reason???

  Is it possible to put another clear layer over the top with an air gap in between, so the rain stays off but air can still flow around, hopefully without disturbing the temp readings too much?

[skyewright]

  Is it possible to put another clear layer over the top with an air gap in between, so the rain stays off but air can still flow around, hopefully without disturbing the temp readings too much?

That's the way I've been thinking.
I've several ideas, which I may or may not get time to try out over the weekend. Some of those ideas involve a sort of 'double glazing' (i.e. 2 layers with an air gap between) using cling film / food wrap...

At the moment other things have a higher priority - the main anemometer failed during a storm yesterday, and some of the other sensors seem to have been at least a little upset by some lightning during the night. The anemometer seems to be a return under warranty job, but hopefully the others just need a sensor reset (when the weather is fit for me to take the covers off to get to the reset buttons!).

[Bashy]

I aint sure i would be able to do the double glazing idea due to the nature of my setup
i.e. the flask, Looks like i will have to lather it in Rain-X and hope for the best

[MichaelPT]

Hi everybody

I thought I would try out the method using clingfilm,

I am using a plastic jar , using a tin disc with a brass tube braised to it
then the temperature probe is pushed inside the brass tube
 For the top I have used clingfilm stretched over very tight and a 2 mm plastic spacer than a second layer of clingfilm

To try out the double glazing method to see how big a difference it makes compare to the glass jar method

I was quite happy with my previous glass jar mod , which worked very well

Glass jar settings  0.1 overcast  0.9 clear sky

mick

[MichaelPT]

Hi everybody

I thought I would try out the method using clingfilm,

I am using a plastic jar , using a tin disc with a brass tube braised to it
then the temperature probe is pushed inside the brass tube
 For the top I have used clingfilm stretched over very tight and a 2 mm plastic spacer than a second layer of clingfilm

To try out the double glazing method to see how big a difference it makes compare to the glass jar method

I was quite happy with my previous glass jar mod , which worked very well

Glass jar settings  0.1 overcast  0.9 clear sky

mick

Hi everybody

Just checked the temperature differential using the clingfilm

There is a very big difference

There is a differential  of 2.0c very fast response

mick

[Bashy]

Thats good news Mick, although that method would not be practical up on the mast for me
When i finally go 1-wire i will then use a separate cloud sensor and no doubt use something along
those lines

At present mine is doing well, i got 4.6 on the CS and 7.0 on the temp
Just need to get it on the mast lol

[MichaelPT]

Thats good news Mick, although that method would not be practical up on the mast for me
When i finally go 1-wire i will then use a separate cloud sensor and no doubt use something along
those lines

At present mine is doing well, i got 4.6 on the CS and 7.0 on the temp
Just need to get it on the mast lol

Hi

 Simon

I think that's the best way to go try and get a one wire system up and running

I'm convinced using clingfilm is the best material to use

The plastic jar I am using is bigger than the glass jar I don't think the rain will affect it using the double glaze system
the whole jar is full of installation there is very little air so I think the device is losing heat to space

Just need to verify the overcast settings  I'll take some pictures and put a drawing on my website
the glass jar method works really good, I still think using clingfilm is giving me the optimum results

It'll be interesting to see what happens when you put your sensor on the poll  you might be surprised

mick

[Bashy]

So the clingfilm method is a lot more responsive then?

I have had to put off the 1-wire for now due to funding, what with bills
and xmas, just had to fork out £300 for the Wii and Wii fit and other Wii bits
for the kids for Xmas, thought i best get the big one out the way, shame though
that could have got me a WMR200 lol

I will deffo go for 1-wire, its just a case of when, cause i really want the barometer
as this has a better resolution than the OS, i hate mine looking blocky on the graphs

I cannot complain about my CS though, it appears to be working well, i cannot comment
on the responsiveness though as its not connected to WD but it does give a good difference
between it and the outside temp, i just hope putting on the mast does not reduce this too much

There seems to be a good range of different cloud sensors in this thread now and all with good
results, i am surprised no one thought of this idea sooner, well saying that i think someone called
Rick or Ricky did but it didnt really catch on then, im glad it has now as you now do not have to
rely on the closest METAR, mine is about 20 to 30 miles away and never really matched my cloude
cover....

oops, im waffling lol

[MichaelPT]

Hi everybody


Here is my latest pictures of my cloud sensor using the double glaze clingfilm system

To get the clingfilm as tight as a drum I used some double sided tape on the outside of the plastic container
then placed the clingfilm over the top of the container stretching it tightly and pressing down on to the double sided tape to secure it

Then, I used a hairdryer a few seconds to shrink the film this makes it as tight as a drum. 
Then I placed a plastic space this was cut out of a plastic plant pot saucer

I placed some more clingfilm over the space, trapping it between the first layer, stretching as tightly as possible
fixing the excess to the double sided tape to keep his in position then use the hairdryer to shrink the film to a perfect finish

The plastic container used is a flower/ shaker plastic container with a lid full of small holes
cost approximately 0.85p

in the picture there is rain drops on the top of the film

Please see image

[skyewright]

Here is my latest pictures of my cloud sensor using the double glaze clingfilm system

Very interesting. Useful tip too about the hair dryer.

My own next attempt is now underway, and I'm taking pictures as I go. At present I'm waiting for the black paint on the disk to dry, so nothing more will be done till tomorrow at least. In some ways my new design is a throwback to the original clingfilm covered polystyrene block, but in a more rugged package and incorporating double glazing.

For some aspects, especially the positioning of the temp probe in relation to the disk I want to do a few indoor experiments so it may be a few days before I have something to show.

[Bashy]

Great illustration Mick, well done

David, when i was making mine i used the heat gun to dry it quicker
Just an idea if ya wanting to get on with it, if no heat gun then ya hair dryer

[skyewright]

David, when i was making mine i used the heat gun to dry it quicker

Good idea, and very tempting, but on this occasion I'll let nature take its course (I have a stack of other things I'm supposed to be doing this weekend).

[Bashy]

No worries, Good luck with it

[meteofrog]

Hi everybody


Here is my latest pictures of my cloud sensor using the double glaze clingfilm system

To get the clingfilm as tight as a drum I used some double sided tape on the outside of the plastic container
then placed the clingfilm over the top of the container stretching it tightly and pressing down on to the double sided tape to secure it

whats about snow? do you think that small space will "pad out" the cooling effect of rain?

[Bashy]

I think snow will be a bad for it prob more so than the rain...

Anyway, at last i have finally got mine up on the mast so will see how
it goes from here on in

I have thought of an idea for the rain though, but its a software remedy not hardware
If its rain then there is some cloud  at least, so how about a check in place, if its raining
then something in the software overrides the cloud sensor output and sets the conditions
to cloudy, how does this sound?