On 5/8/2011 9:32 AM, Dennis Keating wrote:
On 5/7/2011 8:30 PM, AngerManagement wrote:
Only way to check correctly; is to have it tested independently and
the testing place / people to have a test system that is within
Calibration dates and a method / process to ensure consistency etc.
And if your doing it right you will be looking for a target value and
may also look at linearity. Some may be fine at 10 but be out by 1
or 2 bar below 8 or above 12 etc...
For me the Brew gauge only needs a +/- 2 bar range and even then the
accuracy will be +/- 0.5 bar. Thus one could read 8.5 and another
read 9.5 and yet they are 100 % and the actual could be 9. Or they
could both read 9 but the actual could be 8.5 or 9.5....
Have seen 5 separate gauges all get different readings and also
different on different machines.
If you not getting a perfect seal, then any leakage will have an
impact.
Also as any air in teh system is trapped; then compression and release
can cause a flutter AND do not forget and crap / grinds / dirt etc can
cause the OPV to flutter and or have issues.
Vibe or Rotary pump ?
I have a Locally made scace that has a bead to simulate flow
Have seen all sorts of issues with a OPV that would work well when
some one used a blind - ie with no flow; thus lots of excess pump
pressure to work the OPV. Yet when run on my test unit (and a
controlled bled) OR with a puck with coffee in it, the unit would
flutter a bit.
Yes gauges were not in agreement but at the end of the day it was a
dirty / old OPV and a clean fixed it. A while later it was replaced
a steh owner no longer felt he could trust it....
Moral = The gauges are only indicators and the result in teh cup is
what it should be about. Unless using a calibrated gauge with a known
accuracy and a defined response range etc, your stressing over
measurements that you may not fully understand and could lead to
making a Mountain out of a Mole hill.
PS.
Spent many years in a Medical Calibration lab and studied Metrology.
Great field but frustration when trying to explain the detail to many.
Just focus on the big picture.
The gauges your working with; are Indicators, not measurement devices.
well put, anger management. pete, i think you are being too
sensitive to paying attention to your gauge, but with OPV issues, i
can understand it. -Dennis
pete, it could depend on where the pressure gauge is hooked into, re:
boiler or some other place in the system. that is not telling you the
real pressure at the puck that you are interested in. get an extra
p/f and some fittings and a needle valve and hook up a good gauge with
good specs. you can turn the needle valve down to simulate flow during
a pour. then adjust your brew pressure to that gauge, and don't rely on
the other one anymore.-- Dennis
--
You received this message because you are subscribed to the Google Groups
"Brewtus" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/brewtus?hl=en.
