Camera Testing Procedures

"I state that using a 2Mp camera with a defined focal length SHOULD give me my Px/ft ratio at the distance provided by the design software."

I am not sure if you need to do field testing for that, only because it's a straightforward math problem (i.e., if you know the horizontal pixel count and the FoV width, the ppf/ppm is a direct output).

However, what is interesting / important is what the real quality is (i.e., you have a spot - say doorway - where you know that the ppf is 50, but the real visible quality could vary significantly depending on other factors).

I would suspect that most integrators simply measure visibly - i.e., customer looks at image with a test subject (often one of the field techs or their car), if the video looks good enough to the user / manager's eye, it is accepted.