What if:

A sensor has silicon machined micro valve(s) that could
        divert to reading two pressure pathways.
One path is the pressure to be measured over long times >>10 msec.
The other path has a miniature dead weight tester and a small
        one atmosphere fluid reservoir of silicone oil at the end of it.
You arrange so that the pressure on the "to be measured"
        path can be released
        to a serpentine path that is effectively one
        way and keeps cleanliness inside.
Some dead weights are cylinder shaped and their smooth ends
        rest on micromachined silicon ports of a few
        diameters such that pushing on them until flow
        happens tells you when you move through
        a calibrated pressure.
You have silicon micro machined micro motor driven fluid pump
        for small volumes capable of the pressures
        you want to calibrate.
All the above fluid switching is arranged to switch on
        tiny amounts of power
        and could maybe yield a chopper stabilized
        amplifier for fluid pressure...

Remember the HP chopper stabilized millivolt meter?
It had a literal chopper wheel.

John Griessen
Austin TX

> -----Original Message-----
If you
> could use a 0-30PSI (0.1%)  transducer to measure the range between 500
> and 530PSI, you would have a nice instrument, but not for a while.
>
> Wagner
>