The individual increments of the least significant displayed digit on a digital instrument; a meter showing 1.999 V full scale on its 2 V range has a count of 1 mV. Manufacturers quote part of their accuracy spec in counts, for example ±(0.5 % of reading + 2 counts), so the count term dominates at low readings. Resolution usually enters a budget as half a count, treated as rectangular.
Spec is 0.5 percent plus 3 counts, at 10 millivolts the counts are bigger than the percentage.
Also heard as
- digits
- LSD
Related terms
Spec
Shop clipping for a manufacturer's accuracy specification, the published limits an instrument should stay within.
Resolution
The finest step an instrument can display, such as one count of the last digit on a digital readout.
Accuracy
How close a measured value comes to the true value, a qualitative idea rather than a reported number.