X-Mozilla-Keys:                                                                                 
Russell Kent wrote:

Perry Casson wrote:

(the pc scope will not be very well calibrated in the Y axis)

Uh, I don't see why this would be so.  Presumably the software package has a
calibration mode where known voltages are applied to each input (line input
left and right), and the software calibrates the known voltages into the
scale.  Also, presumably the pressure transducers have a linear or
logarithmic resistance response.  Let's face it: a non-linear,
non-logarithmic transducer is of dubious value.

So assuming Paul (or whomever) provides a calibrated voltage to the
transducer, which will then accurately turn the sensed pressure to an output
voltage, which will be read by the software via the line input A/D circuit,
and adjusted via the calibration table, then the Y axis on the output screen
should accurately and repeatably reflect the sensed pressure.

The things to watch out for are:

  1. resistance of the connectors and wires (use the same set for
     calibration and measuring)
  2. non-calibrated voltage source (some have temperature sensitivity)
  3. slow-response transducer (I think Jeff Spitzer mentioned this)

I have a P-133 notebook I'm going to have to load this software on and try
things with.

Russell Kent

 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org