The DAQ card I used was PCI based and is the NI 6052E you can find this on the ni web site, the SCXI rack I mentioned is also a National Instruments piece of hardware as are the signal conditioning modules that reside within it, lots of different options for the modules as they cover a huge variety of signal types, the choice of module is really down to you to specify as it will be dependent upon the output of the pressure transducer.
As for the pressure transducers I use you can find details and pdf specs for them from this page
http://www.hubacontrol.com/en/products/differential-pressure-transmitter/differential-pressure-trans...
Again the exact model will vary depending upon what you are measuring, I would expect a different range of pressure transducer depending upon where it is fittted in the compressor, also watch out for heat build up as this could affect accuracy so remote pipes mounting the transducer away from the compressor will reduce the heat affect but significantly degrade any transient measurement of pressure - Mike
