"Richard Smith" wrote in message ...
Ned Simmons writes:

....
This is crucial to the test - for the peak force to be known and constant.
Would this device settle down to triggering at a very constant
pressure, do you reckon?

-----------------

I don't know about that valve but I do have lots of R&D experience on
difficult projects.

Generally you design and build what you predict (hope) will work, then
measure and correct until you run out of time, money or patience, and
declare it "good enough". The limit is how accurately you can measure.

If the valve is inconsistent you may simply need a better filter, or
different oil viscosity. A recording of cycle intervals and peak pressures
would show you if a problem develops and perhaps hint at why, i.e. was the
change sudden or gradual.

I save measurement data into text files that can be loaded into a
spreadsheet as *.csv for analysis.