The period allowed between successive calibrations, commonly 12 months as a starting default and then lengthened or shortened based on as-found history, usage, environment and the cost of an out-of-tolerance event. Interval analysis methods aim at an end-of-period reliability target, such as 95 % of units found in tolerance. Too long an interval raises false-accept risk on product; too short wastes money and downtime.
Three clean as-founds in a row on that model, let's push the calibration interval out to 18 months.
Also heard as
- cal interval
- recall interval
Related terms
Cal due
The date by which an instrument must be calibrated again, printed on its sticker and tracked by the recall system.
As found
Calibration data recorded on an instrument as received, before any adjustment or repair is made.
Drift
Gradual change in an instrument's readings over time that comes from the instrument itself, not from what it measures.
Recall
The system that schedules instruments back for calibration before their due date, and the act of calling them in.
Stability
The ability of an instrument or standard to hold its calibrated values as the weeks and months pass.