My lab has successfully used iButtons in the past. We suspended the them
in trees (top, middle, bottom of canopy) and placed them on rebar ground
stakes. We needed them to be out for about 3 months so we set the
logging interval accordingly.
The approach I took was to protect them rather than make them
waterproof. An earlier respondent used plastidip, but -- and I can't
remember exactly what the USB button reader looks like -- I would think
this might prevent them from fitting into the reader.
I've included some pictures of what our setup looks like (pics won't be
up forever).
https://dl.dropboxusercontent.com/u/11663005/IMG_20140723_144449.jpg
https://dl.dropboxusercontent.com/u/11663005/IMG_20140723_144531.jpg
https://dl.dropboxusercontent.com/u/11663005/IMG_20140723_144612.jpg
I used 3M command adhesive tabs to fasten the iButtons inside 1 1/4 inch
PVC caps. I chose flat-bottom caps rather than curved caps. I drilled a
small hole through the top of the cap, threaded string through the hole,
then tied knots to keep the cap from moving on the string.
After all this, the caps were covered with foil duct (not Duck) tape ..
the kind used for sealing HVAC ducts and car exhaust pipes. This was to
reflect direct sunlight and allow each iButton to record near-ambient
temperature. Avoid using the stuff with text on it, is shown in the
pictures.
The 3M tabs made it so the iButtons could be removed without damaging
them or leaving residue. I considered using hot glue, but didn't think
it would hold. I've since learned that there is some kind of
industrial-strength hot glue that may have worked.
We lost only one or two buttons because the 3M adhesive failed, more
because they became entangled in trees. I believe that we were able to
read data from all the buttons we recovered.
I remember the software being pretty easy to use, though tedious to
program > 100 buttons.
HTH,
ck
--
Clayton Kingdon
UW-Madison, Department of Forest & Wildlife Ecology
