Very briefly:
LUP (Lead Units of Pressure) and CUP (Copper Units of Pressure) are both crusher methodology units. Due to the different characteristics of lead and copper, LUP was used to describe relatively low pressure cartridges such as shotshells, and CUP was used for cartridges that generated higher pressures (e.g. hand gun and rifle cartridges).
The crusher methodology (regardless of whether LUP or CUP) provided a description of the entire area under the pressure curve.
Transducer (piezo electric) methodology provides a trace of the entire pressure curve, as measured at a specific point in the chamber. The single value commonly reported as the transducer peak pressure is the highest pressure in that curve, as detected at the point of measurement.
Crusher and transducer methodologies dont really measure the same thing. Thats why crusher and transducer pressure measurements can be neither meaningfully compared nor converted from one to the other.
If you want more, see:
http://www.saami.org/specifications_and_information/index.cfmP.S. I just have to ask. Of what are you an engineer?
