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Miscellaneous Debris => Tech Corner => Weather sensors, design, analysis, discussion, home brew => Topic started by: SLOweather on March 07, 2016, 04:46:52 PM

Title: Designing and building my own weather station, notes and discussion
Post by: SLOweather on March 07, 2016, 04:46:52 PM

Well, the copper weather vane has morphed now into as much of a "steam-punk" weather station as I can muster. As you probably have read elsewhere, I have the weather vane and anemometer built, and the anny actually measuring wind speed. I'm still cogitating on the mechanics of how to read the weather vane position. I've chosen a rather obscure industrial automation controller, because I have lots of parts, it makes me a better programmer for our water company, and because I think it will add to the ultimate steam-punkishness of the final project.

The choice of the controller limits my inputs to discrete switches, and 4-20 ma, and 0-5 volt analog signals. I can also have relay and analog outputs as well as a speech board.

For temperature, I've selected LM34s, which produce a voltage output proportional to the temperature in F. It's actually very easy to read, as the voltage in 10s of mv = the temperature in degrees F. (0.75 volts = 75°).

2 of those, a wick and some distilled water, and a small fan make a psychrometer. I can use those temperature values and the barometric pressure to calculate the relative humidity and dew point.

Now I'm on the track of some analog barometric pressure sensors. :)

Title: Re: Designing and building my own weather station, notes and discussion
Post by: Farmtalk on March 07, 2016, 04:55:04 PM

That is awesome! Care to post some pictures of your fine work?  :-)

Title: Re: Designing and building my own weather station, notes and discussion
Post by: CW2274 on March 07, 2016, 04:58:55 PM

Quote from: SLOweather on March 07, 2016, 04:46:52 PM

Now I'm on the track of some analog barometric pressure sensors. :)

There's a ton of aircraft altimeters on sale thru ebay.

Title: Re: Designing and building my own weather station, notes and discussion
Post by: SLOweather on March 07, 2016, 06:18:17 PM

Quote from: CW2274 on March 07, 2016, 04:58:55 PM

Those all seem to be mechanical. I thought about trying to make one analog. I'm looking for something with a 0-5 volt output at say, 800-1100 hPa/mb.

Climatronics has one that would work, but it's $600.
http://www.climatronics.com/pdf_pn/sensors/102270.pdf

First Sensor has one, for $54 in unit quantities, shipped from Germany:

(http://www.first-sensor.com/cms/upload/productimages/products/hca-baro_drucksensoren.jpg)

Title: Re: Designing and building my own weather station, notes and discussion
Post by: SLOweather on March 07, 2016, 06:20:54 PM

Quote from: Farmtalk on March 07, 2016, 04:55:04 PM

That is awesome! Care to post some pictures of your fine work?  :-)

There's a thread on the mechanics of the weather vane and "add-a-mometer" here:

http://www.wxforum.net/index.php?topic=27818.0

and more on the anemometer sensing and calibration here:

http://www.wxforum.net/index.php?topic=28573.0

Title: Re: Designing and building my own weather station, notes and discussion
Post by: SLOweather on March 22, 2016, 01:48:11 PM

The work bench was getting too cluttered, so I built a stand to hold the controller, display, fuse block, servo controllers, and the demo servo driven gauges.

(http://www.sloweather.com/blog/2016/160322wxstabench.jpg)

Now there's more flat real estate for other work. :)

Title: Re: Designing and building my own weather station, notes and discussion
Post by: PaulMy on March 22, 2016, 01:57:12 PM

Everything except baler twine and duct tape...
 
Paul

Title: Re: Designing and building my own weather station, notes and discussion
Post by: Garth Bock on March 22, 2016, 02:24:03 PM

Quote from: PaulMy on March 22, 2016, 01:57:12 PM

Everything except baler twine and duct tape...
 
Paul

What??? No chewing gum ????