OT? Q: Steam pressure gauge
 

Bart wrote:
Hi all,
This is probably going to be a stupid question but,
I'm trying to get a reference on a pressure/temp gauge on an old
pressure canner.

I've hooked up a bicycle pump via a tire valve & hose to the pressure
canner & the pressure canner reads 15 PSI and the bike pump reads
~12.5 PSI at room temp.
I've also checked the bike pump pressure gauge against a new spare
pressure gauge & they seem to be within ~1 PSI.

My question is, will the steam/temperature affect the pressure cooker
gauge differently than just pumping it up with room temp. air?

I know I should just go buy another gauge, but I really like the looks
of the needle/indicator face of the old beast!

Opinions on bourdon tube "home re-calibration"? ;-)

TIA!
Bart

Pressure is pressure, whether it's stram or air.

Temperature *shouldn't* significantly affect the canner's gage reading,
but if you want to prove whether it does, heat the gage up with a hair
dryer until it feels about as hot as it does when it's in use and try
your air pressure test then.

Larger old bourdon tube gages did have internal adjusters which modified
the "leverage" of the linkage between the bourdon tube and the rack
which rotated the indicator shaft's pinion gear, but I doubt if a little
gage like yours has that provision. OTOH if you can easily open it up,
have a look, you may see where there's a spot for bending something in
the linkage to change the leverage.

HTH,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."