ACR Stick-on data loggers

Paul,

>A clear disadvantage is that they don't
>provide a visible reading of current conditions; that is, data are
>only accessible via downloading to the computer.

I'm terribly surprised to learn this.  I hadn't gotten that impression
from the promotional material.  Until now I have been feeling rather
distressed that we bought our rustraks just before we got the info
about acr's (instant obscelescence), so now you give me a shred of
pleasure, as the rustraks allow real-time monitoring of up to 4
channels at once (well you only see one channel at a time, but it is
no big deal to switch from one display to another).

>There is unquestionably a snake in the grass with these; they
>are so neat and high-tech that it may easily be forgotten that they
>need to be periodically recalibrated against an instrument of known
>accuracy, 

The Rustrak manual expects you to calibrate over a saturated salt
solution inside a chamber (oh what fun) (at least that's what my
memory tells me).  I suspect we will send ours back to the factory
every so often and let them have the pleasure (this is what we used to
have to do with our old rustrak electronic hygrothermograph).

>The software supplied with the instruments is somewhat
>primitive; much better information can be obtained by downloading the
>data into a spreadsheet and massaging (and graphing) it that way. But,
>more time and effort.

I'm curious what sort of analysis you would do that isnt handled by
the acr software?  (smoothing comes to mind).  My main reason for
offloading the data is to keep a database, but I suspect we will find
cause to get fancy one of these days.  For a current project we were
monitoring in two areas, one controlled, one not and trying to
document a need for intervention in the troubled area.  Alas, someone
turned the electricity off in the controlled area (we never quite got
around to buying batteries), so....

My next instrument had better come with an armed guard.
w

                                  ***
                  Conservation DistList Instance 4:57
                   Distributed: Saturday, May 4, 1991
                        Message Id: cdl-4-57-001
                                  ***