Question 3-74L1

A "1/2 digit" on a Digital Multimeter (DMM), often seen in specifications like "3 1/2 digits" or "4 1/2 digits," refers to the leftmost digit on the display. Unlike the full digits which can display any number from 0 to 9, this "1/2 digit" can only display a 0 or a 1 (and sometimes up to 2 or 3, depending on the meter's maximum count). This feature allows the DMM to read values slightly above a standard full-digit range without switching to a higher, less precise range. For example, a 3 1/2 digit meter can often display up to 1999 counts, effectively extending its measurement capability from 999 to 1999 without losing the resolution it had in the 0-999 range. This provides "partial extended accuracy on the lower part of the range" because you maintain the same resolution (e.g., 1mV) from 0V up to nearly 2V, rather than being forced to switch to a 20V range with coarser 10mV resolution once you exceed 0.999V. This improved precision is valuable when making measurements in amateur radio circuits.