A final response to Pete Knoblach's loud piano.  You are wasting your
time charting anything with a gauge from Player Piano Co. These things,
at best, give a fair reading at mid-scale.  At the low end they are
worthless.  A cheap (the price may have been high) Bourdon tube gauge
has so much internal friction and gear slop that it is entirely random
at the low end.  Use a water column or a good gauge or two and check
them first against a water column.  Gravity doesn't lie.

If you don't want to get water near your piano, the best gauges for the
money are the Dwyer Magnahelics which can be gotten from W. W. Grainger
Co.  If you can't buy from them, most hardware stores will order from
them for you.  You can get a good gauge for less than the cost of the
Marshalltown (or whatever) from Player Piano Co.

Pat Mallarky's scheme of using a low end gauge and a high one is also
what I do.  Most gauges are designed for best accuracy at mid scale, and
most state the accuracy as a percentage of full scale.  This makes
anything but a precision gauge useless at the low end, but this is just
where the critical reproducing piano range lies on a 0 to 100 wci gauge.

The important thing, though, is to set up the piano properly in all
respects, and it will make the right levels.  You can't fake a Duo-Art
up to a set of vacuum levels and have it make music.  Find out what is
wrong and fix it.  If you can't get the piano to play properly following
Craig's set up procedure, something is wrong. I spent months trying to
get my first Duo-Art to play properly, adjusting and readjusting etc.
What it needed was a complete rebuild.

Spencer Chase