Thanks Alan G. Using a flat light source like the monitor and an overcast day which I just tried, the Minolta reading matches the EV readings from the digital camera settings and the Sekonix meter. I feel all three are equal in calibration. Since the digital camera takes perfectly fine pictures, it's meter is acceptable. So all three units are in calibration.
In playing with the camera, I'm realizing that it may be the best instrument to use for meter readings. Since you're able to see the actual picture it's taking and the histogram, what better instrument to use to set up my film camera? Years ago I bought a polaroid attachment to the Mamiya RB67 just for that purpose. So you can test a Polaroid shot first to see if you got the exposure right before inserting and using film. Well, the digital now becomes the Polaroid shot. The only issue might be if the digital camera is taking the correct exposure but the readings of where the aperture and shutter are working does not match.