I am an EE, Denton that wrote that article is an EE, and we have debated on and off for over a decade. There is a third EE, Glenn, who really debates Denton more than me.
My attitude is that anyone can buy a CEA-06-250UW-350 strain gauge, glue them to the outside of a rifle chamber, put a Wheatstone bridge around it, design a much better instrument amplifier than Oehler just by using modern op amps, hook it up to a garden variety storage scope, and voila, get a trace. The interpretation of that trace into something useful is going to be harder. The book of stress vs strain formulas for complex shapes is by Roark.
http://www.amazon.com/Roarks-Formula.../dp/007072542X
I do not think you will find that chamber and barrel taper open ended tube shape as a plug and crank formula.
I do not think you will be able to quantify the error introduced in how the strain gauge was glued.
This leaves one with a trace that cannot be directly tied to NIST.
Another layer of useless comes from the fact that if one did have something traceable and so did have actual psi, what would you do with it?
The SAAMI registered max average pressures for a given cartridge are fairly off the wall and arbitrary for the advanced reloader. He is more interested in real feedback from the real weak link, the brass.
I have all that equipment.
I am not doing it. Two layers of uselessness are enough to make me find something better.