Coulomb Meter
Description:-

Coulomb Meter is a useful tool and behaves similarly to a Digital Electroscope. 
An electroscope will deflect its vane but this instrument shows the charge digitally in Coulombs up to 199 nano Coulombs, Accuracy + 10 nano Coulombs.    
Either by current through a resistance or from a capacitor or from a source of static electricity (a charged plastic rod).
The display will show the number of Coulombs deposited into the instrument.
 

Coulomb Meter