Quote Originally Posted by polyglot View Post

Second question is "what is the offset between speed point and metered reading?". In other words, where on that H-D graph is the "average reflected reading" going to fall? Is it at n, i.e. Hn = Hm+1.3? This is basically a re-statement of my original question for this thread, trying to directly relate light readings in lux-s at subject and at film.
You've already answered this. The ratio is usually noted as n sub 1. I did a thread on this subject "What is the relationship between film speed and camera exposure?" I've also attached a paper that you might find interesting, Connelly's "Calibration Levels of Film and Exposure Devices."

Calibration Levels of Films and Exposure Devices, Connelly.pdf

Did you successfully make a test-strip at that exposure and have the speed-point land where you expected it on the test strip? What if you set the meter to ISO400, that should get it to read a larger aperture: f/1+0.7 at the correct light level (assuming the limitation is the meter's display and not its sensitivity).
My sensitometer is (or at least was) calibrated. I did use those Log-H equations to determine which step tablet density I wanted the speed point to fall. Worked perfectly.