I've been using a fairly cheap homemade IR based cloud sensor for the last few months and it seems to be working pretty well.

I've just upgraded to a new IR thermometer which measures the sky temp down to -40C, increasing the usefulness in low ambient temps over my old sensor which only measured the sky temp down to 0C.

The new sensor costs about $145 at retail, which is a fair bit cheaper than the current Boltwood sensor ($1500), although it doesn't measure windspeed nor does it have a rain sensor. It does measure relative humidity, which may possibly be used as an indicator of rain though?

The way I figure things, if there are no clouds, there's unlikely to be any rain, so this is better than nothing...

Anyway, I've written some monitoring software which takes the readings from the sensor and graphs the cloud conditions - my live sky status page is viewable here:

http://winfij.homeip.net/CloudStatus.html

I'm considering integrating this into an ACP weather server app which will then be able to initiate an ACP shutdown when the clouds roll in - is there any interest from anyone in having this capability available from a DIY solution?

I bought my IR thermometer from here:

http://www.kvmtools.com/servlet/the-...C-RH401/Detail

It's got an RS232 output, which you just need to hook up to a PC and run my data gathering software. It takes a 9v DC power input (not supplied).
You'd need to build a sun/rain-proof container for it - I used a modified plastic snaplock food container, with a sensor window covered with kitchen clingfilm (seems to be transparent to IR).

So, any interest in me extending my graphing software into an ACP weather server, to give a low cost DIY cloud sensor solution for automated observing?

Cheers,

John