What is Digit?

A measure of the display span of a panel meter. By convention, a full digit can assume any value from 0 through 9, a 1/2 digit will display a 1 and overload at 2, a 3/4 digit will display digits up to 3 and overload at 4, etc. For example, a meter with a display span of ±3999 counts is said to be 3-3/4 digit meter.