Resolution Digital Voltmeter

voltage measurement

If I have a 3 and half digital voltmeter operating on the voltage range of 40V then what would be its resolution? While trying to solve this I found in one of the books that only active digits ( which in this case are 3) will be used to calculate the resolution. However doing so I was getting the wrong answer. Is this method not correct?

Best Answer

3 1/2 digits means the most significant digit can only show a 1 or nothing at all, so the most segments that can be displayed are 1888.

A 40V range would not be able to use the most significant digit, so you only have 3 digits that can be used to display the value, so you can only display up to 40.0

So your least significant digit there represents 100mV (0.1V), which is your resolution.