The FLS is a nice tool added to my arsenal. The PicoScope compliments it quite well. What your interested in is an ultra sensitive differential pressure sensor. (piezo design) The Fluke PV 350 (if this is what your using) is designed for broad ranges. On the high end with that you can measure cylinder pressures at their peak. The FLS is not your tool for this. It's a highly sensitive measuring device for small pulses. Intake, exhaust, fuel pressure regulators etc. Keep in mind, all engines are different for diagnosis using this sensor. They all have their own characteristics.