Hygrometers

[Dennis Johnson]

At  5:38 PM 3/30/95 -0700, k.swafford@genie.geis.com wrote:
>
>     As to the accuracy of these devices, I think it is impractical to
>send these things in for regular calibration, especially if the
>calibration costs as much as a new device.  Remember that these
>devices are not claimed to be very accurate in the first place.  I
>say, round off all the readings to the nearest 5%, which should be
>sufficient for our purposes.  Then, get a second device, either by
>buying one or bringing together a lot of the devices of various makes
>and models at a PTG meeting.  Then when the rounded-off readings don't
>agree, opt to buy new or get a calibration.


___________

Kent:
        Its good to hear from you again! I really was beginning to wonder
what might have happened.

        You and John Minor both have a valid point about not getting too
anal retentive about accuracy here, at least for our general purposes.
Accuracy became an important issue for me here at school last winter when
the department (meaning mostly myself) really pushed the problem of
humidity control in our building with the physical plant (who controls the
climate system). To make a long story short, in the end they insisted that
everything was fine and my readings just must be off. This went back and
forth, but this winter it has been many times better. In spite of the mild
winter I am giving them a little credit.
I also think that my case as presented to them ultimately paled in
comparison to the effect caused by the bills some faculty forwarded to them
for repairs of split cellos and violins.
        Anyway, most of time reasonable accuracy is fine. However, I do
maintain that, as authorities of piano care, we should be aware, and
regularly check the accuracy of information we offer to clients. +/- 5%
R.H. really is a lot, and could mean the difference between having no
problem, or having cause to get concerned.



Dennis Johnson