Informal word for adjusting an instrument, usually a minor trim of a potentiometer, a calibration constant or a zero. In a cal lab it carries a warning: tweaking before recording as-found data, or tweaking an in-tolerance unit without need, erases the drift history the lab relies on to set intervals and assess OOT impact. Many procedures spell out when a tweak is allowed.
Don't tweak it yet, it's in tolerance, log the as-found and move on.
Also heard as
- trim
- touch up
Related terms
Adjustment
Changing an instrument so its readings move closer to the correct values, a step separate from calibration.
As found
Calibration data recorded on an instrument as received, before any adjustment or repair is made.
As left
Calibration data recorded after adjustment or repair, showing the condition the instrument returns to service in.
Drift
Gradual change in an instrument's readings over time that comes from the instrument itself, not from what it measures.