Stability is put in numbers as the change in a calibrated value over a stated period, such as 2 ppm per 30 days for a voltage source. Short-term stability matters during a single calibration session; long-term stability decides calibration intervals and how much drift allowance the budget carries. Transfer and check standards are chosen above all for stability.
Stability on that thermocouple reference is terrible, it moved 0.3 degrees in a week.
Also heard as
- long-term stability
- short-term stability
Related terms
Drift
Gradual change in an instrument's readings over time that comes from the instrument itself, not from what it measures.
Check standard
A stable item measured regularly to confirm a measurement process still behaves as it did when characterized.
Transfer standard
A stable, portable standard used to carry a value from one lab or standard to another for comparison.
Calibration interval
The scheduled time between calibrations of an instrument, set to keep the chance of drifting out of tolerance low.