Mike DeMetz wrote:
> Got an invite letter to a session at the Sensor Expo Show (Cleveland,OH
> 9/15) by Maxim on their 'next-generation pressure sensors'. First units to be
> 100-3500 kPa in PCB mount package featuring;
> On-sensor-chip fluid media compatibility
> On-sensor-chip vacum reference
> Plug and Play operation eliminating need for external compensation and
> amplification.
> +-1.5% total error band over temperature range.
> To be followed by higher pressure models(to 350Mpa) and threaded port
> packages.

Hi Mike, 1.5% of error is somehow high for certain applications, and
fair enough for other.
For example, I built a device using a 24bits ADC to keep the 0.1% of
some (Lucas Novasensor) pressure transducer to be used in a
calibrator/indiator. Software temperature and range calibration was a
must, so the actual instrument error spec is just caused by the
transducer drift against the calibration itself (repeatability error).

This is one area of measurements that was not evoluted enough.  We can't
ensure 0.01% of accuracy in a pressure transducer, except if you pay
more than $300 for it... someday somebody will find out a different way
to measure pressure.  It is a nasty physical variable, you *can not*
easily add, subtract, multiply or divide it. The transducers should be
able to cover all the range at once, so the accuracy problems.  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