To all:

I've found a source of *very* good, very inexpensive Vacuum Gauges!   Much
to my surprise, I found that the price of a new Dwyer MagnaHelic gauge is
very, very low!

To those who don't know the MagnaHelic gauge, it is a 6" diameter, 2%
accuracy, *very* well built family of gauges. They are extremely
sensitive, but tolerate large over-pressures.

A brand-new MagnaHelic gauge in 0-10", 0-20", 0-30", 0-40", 0-50", or
0-60" (all "water column inches" - "wci") from my local distributor was
quoted at only US$ 49.95 each.  These are 6-inch diameter differential
pressure gauges.  Many, many other ranges are available.

I found this price to be almost incredibly low!  (The 30" or 60" cheaply-
made bourdon-tube type gauges from the various piano supply places vary
from $75 to over $100!)

Actually, I didn't really believe it, so to check it out I ordered a 0-40
wci gauge from my local distributor.  Three days later, and $56.61 (sales
tax added) later, I received the gauge!  And, it's a true MagnaHelic, with
all the extra plugs and mounting hardware!  Brand new, off-the-shelf.

I now have a MagnaHelic 0-10" I got from Spencer Chase and the new
MagnaHelic 0-40" teed together for pressure measurements. No need to
switch gauges for low and high pressure readings. The 0-10" gauge is rated
at 15 psi (around 360 wci !) over-pressure, and won't be disturbed by
pressures in the 30"-40" range -- which the second gauge then displays
correctly.

I should add that the MagnaHelic gauges also have a zero-adjust screw --
unlike the bourdon-type gauges which drift off zero over the years -- and
aren't usually adjustable without breaking open the case.

I would say that the only drawback to the MagnaHelic gauges is that they
are somewhat large.  But, that's compensated for by being highly readable.

If you don't have a Dwyer distributor/representative available to you,
I could possibly arrange to obtain them on order for purchase price plus
tax and shipping and handling -- though I'm *not* in the retail business
in any way -- and don't want to be. ...