what is the least count of a measuring instrument

The least count of a measuring instrument is the smallest value in the measured quantity that can be resolved on the instruments scale. It is the minimum measurement interval that an instrument can discern, and it serves as a fundamental indicator of the instruments precision. The least count of an instrument is related to its precision; an instrument that can measure smaller changes in a value relative to another instrument has a smaller "least count" value and is more precise. Any measurement made by the instrument can be considered repeatable to no less than the resolution of the least count. The least count of an instrument is inversely proportional to the precision of the instrument. The least count of an instrument is a measure of its precision and accuracy. The error in the measurement by an instrument is equal to the least count of the instrument. The least count of an instrument is calculated by dividing the main scale reading by the total number of divisions on the main scale. If the instrument also has a secondary scale, then the instruments least count is the ratio of the main scale least count and the number of divisions on the secondary scale. The least count of a measuring instrument is the smallest distance between two consecutive divisions and is equal to 1 MSD - 1 VSD. The least count of measuring instruments varies depending on the type of instrument. For example, the least count of a vernier caliper is 0.02 mm, while the least count of a digital micrometer is 0.001 mm.