Ok. No one has suggested taking some data.
Actually, this was addressed in the first two posts. He noted calibrations. I took him at his word. The very next post asks about thermometer calibration.
The rest of the posts are perfect, Tom. Yes, Calibration batches may be in order.
Whenever I consult with a new brewery, I always ask for either a calibration batch to be made or to see the data from one. That never precludes problems, but is isolates variables.
My calibration batches are always the same: a precise amount of 100% pale malt (homebrew scale, 10 lbs, exactly) and 35 IBU boiling only, targeted. The resulting beer isn't much (dry hopping helps a lot), but it can be used to gauge crush, efficiency, fermentability, temperature stability, absorption pH, losses and chill haze reduction. It also reveals a lot of other things like kettle temperature slopes, pump performance and stuff you need to know in a commercial setting.
One important data point for every brewing session is to take first wort gravity readings. Not only is this a better reading to identify full conversion (iodine is a flawed and obsolete method), but it also tells you 50 to 60% of your pre-boil gravity.