Low cost cloud monitor

[Jack Harvey]

My boltwood I died and of course the new cloud monitors run from $450 to $1800    However some research turned up one for $90.00.  It is a IR thermometer that also has an ambient temp sensor on the board.  It takes the IR temp and subtracts the ambient temp, which is what the other cloud monitors do.  The company makes a $8 enclosure that you can waterproof with silicone, cover the IR lens with plastic wrap and it is ready to go.  Interfaces with your computer via usb.  You will have to write some software, but I have noted that does not seem to be a problem on this forum<G>  It does not have a heater or the ability to detect rain so you have to rely on your weather station for that.

Anyway for those looking for a new project:    http://www.phidgets.com/products.php?category=6&product_id=1045

[NKV]

Something wrong:

Ambient (Board) Temperature Range    -40 to +125°C 

Operating Temperature    0 - 70°C

[Jack Harvey]

From the user manual  http://www.phidgets.com/documentation/Phidgets/1045_0_Product_Manual.pdf

 
Measured Temperatures
The 1045 is factory calibrated in wide temperature ranges: -40 to 125 °C for the ambient temperature and -70 to 382.2 °C for the object temperature.
To get the most accurate reading, it is important that the object being measured occupies the full field of view of the sensor while not making physical contact with the sensor. In addition, the temperature of the object and of the environment also affect the overall accuracy. The highest degree of accuracy is +/- 0.5 degrees Celsius when both the ambient temperature and the object temperature are between 0 and 50 degrees Celsius. As either temperature changes, the accuracy can decrease to up to +/- 4 degrees Celsius.
The measured value is the average temperature of all objects in the 10° Field Of View of the sensor. The sensor is configured to continuously transmit the temperature of the measured object every 32ms.

[Silvercup]

Hi Jack:

I'm developing a remote observatory control, one of the first thing I did was an IR thermometer to measure the Sky Temp. The IR Thermometer is very cheap, The MLX90614 from Melexis cost less than 16 Euros, and is very easy to implement with an Arduino board.

A rain detector like the one used in AAG Cloudwatcher only cost 5,45 Euros.

So I can't explain myself why a Cloud detector can be as expensive as 800$ or so.

Silvercup.

[Jack Harvey]

Exactly my thoughts on the cost of the cloud/rain detectors Silvercup!  BTW the Boltwood II is not $800 but $1700!

[RBA]

So people like to make a lot of money on single units they sell, that's all  8)

[mmirot]

Keep us posted on the software development

Max

[Jack Harvey]

Phidget arrived and the only hard part was assembling the acrylic case that comes in 6 parts (G).  It is plug and Play.  Install the driver, plug in and then open the Phidget Manager to recognize the device.  Then Open the Temp sensor and I have a window that continuously reads out both Ambient and IR temp in Centigrade.  Now the next thing is to try to graph the outputs as the Boltwood uses Sky Temp(IR) - Ambient Temp (C)  to predict clouds.  You have to run it a few times to see what a clear dark sky and varieties of cloudiness so to the temp and you are good to go.  The Phidget site has several programing languages and examples to deal with scripting but I am not too sharp in this area.

[Jack Harvey]

Well we ran the Phidget cloud monitor and it worked great with good correlation to our skies.  Temps colder than 27C we clear and from 22 to 27 partly cloudy.  Under 20 or so very cloudy.  I have attached a graph created by the scripting talents of Kevin Ivarsen who we work with on UNC/PROMPT in CTIO.  Since this script is created on grant money time I am not sure I am at liberty to share the script.
 I suspect
However as I mention another person is working on a script and from what I see of this forum there are lots of guys than can bang it out in a couple of hours like Kevin did.  All his script does is graph, but a GUI letting the user select the Clear, Partly Cloudy and Cloudy thresholds would be nice as each site varies for these values.  Also might want to have it call out a .bat command which could be used to close the dome, say if cloudy remained for 15 min.  Other options would be to send email or msg to your devices or a .wav alarm???  Could also be integrated with automated imaging programs like CCDAP or ACP I suspect.  Graph can be seen:

http://salsa.skynet.unc.edu/skynet/weather/graph/8/relskytemp?range=10800

[mmirot]

My only concern is the short distance USB can cover to get to a roof

Max

[mmirot]

http://rainsensors.com/


Might be a nice addition to the system

Max

[Silvercup]

Hi:

This one is more cheap.

http://www.brocott.co.uk/electronic-devices/sensor-devices/electronic-rain-sensor-module-p-388.html

Or you can do a AAG like with this one.

http://www.lextronic.fr/P1784-capteur-de-pluie-ibr273.html

Silvercup

[andre germain]

I've been using the Phidget 1045 since early 2011, and it's been excellent. You can read a tad more on my installation here; http://www.watchobs.com/astronomy4.html [scroll half way down]. I use it in concert with my own extensive observatory s/w and ACP to be fully autonomous, and the Phidget has enabled this with 100% reliability. I wholeheartedly recommend the Canadian product as a low cost alternative to the Boltwood, AAG and Fosters units, although of course these offer more [but these features are easily added for a fraction of the price].

Cheers

[andre germain]

http://rainsensors.com/


Might be a nice addition to the system

Max

I purchased this unit (50$ USD) and it is outstanding. I've got a small write up of it here:

http://watchobscom.ipage.com/astronomy5.html

Cheers

[mads0100]

It's showing that it is no longer available???