Charge Sensor
Description:-
The Charge Sensor can make quantitative measurements. 
Numerical measurements improve many electrostatics experiments.
An extremely high-impedance voltage sensor with a 0.01μF input capacitor makes these measurements possible. 
The sensor can also be used to measure charge polarity. 
The sensor has three operating ranges and a zeroing switch to discharge the input capacitor.
Such as charging by induction, charging by friction, and charging by contact.
Specification:-
Maximum input: ± 150 V
Input capacitance: 0.01 μF
Typical bias input current: 0.005 pA
Instrument time constant: 0.1 s
Ranges:-
± 2 V (± 20 nC)
± 0.5 V (± 5 nC)
± 10 V (± 100 nC)