Environmental Extreeme Testing

[Jonathan Brier]

Hey everyone,

I am following the AQE discussion checking in every so often. I could not find much detailed discussion on environmental testing the enclosure and electronics designs. (http://en.wikipedia.org/wiki/Environmental_tests)

The environmental testing may have been informed by leaving the test systems outside, but a planned test with metrics for performance on temperature extremes, humidity, and various forms of precipitation and wind are what I am most curious about. IF these have been conducted as I saw some variables were considered in the indusrial design on the wiki, but did not see the tests outlined or results evaluation listed at http://airqualityegg.wikispaces.com/Industrial+Design?

I also the recent post that the circuits adjust for the environmental variations, but what extent can these adapt? Can they handle the cold of the winter in the north -40 degrees Fahrenheit or the hot tropical humidity of an equatorial deployment 100+ degrees Fahrenheit and near 100% humidity for long periods of time (>6 months).

If the test conditions and methods are outlined as more people hack new versions they could use those methods to compare performance and see if there is improvements or decreases in any evaluation criteria for the new designs.

Anyway I thought I'd ask as this group is closer to the development and testing than I and possibly prompt a discussion on the subject if it has not yet been discussed.

Cheers,
Jon

[Ed Borden]

This is really really important, and a bunch of people have expressed
concern to me over the Egg's ability to withstand environmental
conditions in their areas.

I'm afraid that timing and lack of expertise in this area will squeeze
tests of this nature out of the process. If you, or anyone else, can
do comprehensive environmental tests I would definitely be happy to
get you a prototype to help us out with it.

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[Matthew Dance]

We are planning on testing in Edmonton over the winter - we expect to experience as cold as -40C, and will have the monitors set-up adjacent to Alberta Environment's regulatory AQ sensor for comparison.  If you can support this with a AQ Egg or two, it would really help out.

Thanks,

Matt

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| Matthew Dance | 

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[Dirk Swart]

Hi Matt,

I don't recall the tolerances offhand, but can pretty much guarantee the egg will not work at -40C. That's cold :)

Cheers
Dirk

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[Victor Aprea]

The AC/DC switching power supplies would probably be the first to fail. If they were kept our of the cold (e.g. indoors) I'm not sure what would go next.

Vic

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[Rajesh Sankaran]

Most of the Atmels are rated - Industrial (A) (-40°C to 85°C). Now that is close to their limits. And 

I thought there was some coil being heated etc. in the sensors toward acquiring the measurement. 

If so, I wonder if one can even heat up the coil and bring them to operating temps at that ambient

temperature. Please correct me if I am wrong. I checked out the weather for Edmonton on Wikipedia,

and it looks like a cold - dry place, with as many as 28 days in a year with temps below -20C. Frozen. 

Thanks!

Rajesh

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[Cesar Garcia Saez]

Maybe having them inside one of our famous "coke bottle split in half and covered in tinfoil" enclosures could raise temperature a bit. These nanodes can run pretty hot :-)

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