Jeff Liebermann wrote:
On Tue, 29 May 2012 15:45:59 -0700, John Robertson
wrote:

And if you don't keep it clean, dust/dirt can affect the results...not
to mention wasps possibly finding the inside attractive for a nest (grin).

On the other side of the building, the property owner has 5 bee hives.
I've become somewhat accustomed to having honey bees buzzing around my
head when working on the radios in the building. Dirt and dust are
not much of a problem. Corrosion damage to the cheap RJ14 connectors
and flat ribbon wire is more of a problem. Whatever inspired the wx
station manufacturers to use telephone connectors is beyond my limited
imagination. Extra credit to Peet Bros for using an RJ50 connector.
That's a 10 pin version of the common 8 pin RJ45 connector.

Yup, it is difficult to have precision readings that are consistent over
time. Calibration, calibration, calibration...

The theory is that if you design it randomly, build it randomly,
install it randomly, and poll data randomly, all the errors will
cancel each other out resulting in an accurate reading. Never mind
calibration. Just randomize everything.

So is that how some researchers get accuracy to .001 using
hundreds/thousands of devices calibrated to 0.1?


I'll confess to having done the ice and boiling water calibration
ceremony to various thermometers while in college, but not to a
wireless sensor.
http://www.in.gov/isdh/files/ThermometerCalibration__3_.pdf

Put the sensor in a baggie and suck the air out then see how it measures
up...

John :-#)#


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