Definitions for "Vernier scale"
A small, moveable graduated scale adjacent and parallel to the main scale of an instrument. It provides a means for interpolating between the graduations of the main scale.
A short scale added to the traditional 3 inche (7.5cm) scale on stick barometers to give more precise readings.
a small movable scale that slides along a main scale; the small scale is calibrated to indicate fractional divisions of the main scale