I think I may have found the answer to the question I just posed! In the test strip package insert for my Accu-Chek Aviva test strips, it says: "The Accu-Chek Aviva Plus system is plasma calibrated to allow easy comparison of results with laboratory methods." I wonder if all of today's meters work this way.
I'm changing endos and my new endo is part of a diabetes education center that has an in-house lab. I asked the center administrator if I could get a glucose test every three months so I could compare my meters with their lab standard. She said that's OK. I'll be checking my meters against the lab soon.