Least count

Any measurement made by the instrument can be considered repeatable to no less than the resolution of the least count.

A stopwatch used to time a race might resolve down to a hundredth of a second, its least count.

Least count uncertainty is one of the sources of experimental error in measurements.

A metre ruler may have graduations at 1 mm division scale spacing or interval.

Instruments of higher precision can reduce the least count error.

The dieter's problem: this scale can only resolve weight changes of 0.2 lbs, even though the digital display looks as if it could show 0.1