OOT stands for out of tolerance: the instrument's as-found error at one or more test points exceeded its tolerance when it arrived for calibration. An OOT finding triggers an impact assessment, because every measurement made with that instrument since its last good calibration is now suspect, and customers or production are notified when product may be affected. The item is then adjusted, repaired, limited or retired.
That pressure standard came in OOT at 3000 psi, pull every job it touched since its last cal.
OOT is judged on as-found data; an instrument adjusted back into tolerance is still logged as OOT for the record.
Also heard as
- out of tolerance
- out-of-tol
- OOT condition
Do not mix it up with
- Out of cal: Out of cal means the due date has passed; OOT means the instrument was measured and found outside its limits.
Related terms
As found
Calibration data recorded on an instrument as received, before any adjustment or repair is made.
Out of cal
Past its calibration due date, so the instrument is not approved for use regardless of how well it performs.
Red tag
A reject tag marking an instrument as unfit for use, or the act of pulling one from service with it.
Tolerance
The allowed deviation from nominal that an item or instrument may show and still be accepted.
PFR
Probability of false reject, the chance that an item actually in tolerance is measured and failed.