"Precise" is an imprecise term.
To what accuracy do you want the measurement: ±1.0", ±0.10", ±0.010", ±0.0010", ±0.00010"? At what temperature?
What is the manufacturing tolerance? If you measure one roll, how close will that be to other rolls from other manufacturers.
Why can't you measure your own film? If you plan to use the information requested, you
must surely have tools sufficiently accurate to measure whatever you're working on.
Why do you need the information in the first place?
- Leigh