State significance of ½ digit with an example
The number of digit position in a digital meter determine the resolution. ½ digit has a maximum value of 1 and has 2 possible conditions (0 or 1). Hence 3 digit display on a DVM for a 0 -1 V range will indicate values from 0-999 mV with a smallest increment of 1 m V. Normally, a fourth digit capable of indicating 0 or I ( Hence called a half digit) is placed to the left. This permits the digit meter to read values above 999 up to 1999, to give overlap between ranges for convenience, a process called over ranging.