The really ironic thing is that if you want a really good meter you still usually have to go for a moving coil electromechanical meter as digital ones just will not display all the information. For example if you have a DC signal with an AC component the digital meter will often just show you the average voltage, whereas you can see the needle wobble on a moving coil meter. For this reason I own several of both,
You need meters that work down to pA for some work with instrumentation and need ones that work in the uA and mV range for op-amp circuits etcetera.
Those qualities can be measured, but probably not with a common DVM. An oscilloscope or other even more sensitive instrumentation would probably be needed. Regular multimeters are designed for "real world" measurements that are most useful to us electricians and technicians, around 1mV or a tenth mA. Most day to day measurements don't need to be more sensitive than that. A circuit called a "balanced bridge" is capable of measuring tiny variations in current.
because on a lot of circuits there are nodes where the voltage or amperage are micro amounts so you have to have a meter capable of measuring those micro amounts.
Using a meter that measures 1V increments would give you a reading of zero if the voltage was truly 0.45V and likewise if the voltage was 1.46V it would read 1 volt. So accuracy has to be in line with the components outputs you are measuring
I have a Philip PM2404 can measure 0 to 1uA and 0 to 100mV.
