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Operati on
3
Operation
The controls on the front panel of the electrometer are explained in Figure 1. Whether you’re using the electrometer to measure
voltage, current, or charge, the following procedure should be followed each time you turn on the electrometer.
More information on making accurate measurements is provided in the sections that follow.
Setup
1.
Connect the BNC plug of the signal input
cable (test lead) to the BNC jack on the side of
the electrometer. Line up the pegs on the BNC
jack with the slots on the BNC plug. Push the
plug onto the jack and turn the plug clockwise
one-quarter turn until it is secure.
2.
Use the banana plug patch cord to connect the
ground port of the electrometer to an earth
ground.
3.
Press the ON-OFF push button to turn the elec-
trometer on. The digits display, the meter dis-
play, and one of the voltage range indicators
will light up.
4.
Press the ZERO button to zero the electrome-
ter. The light emitting diode (LED) of the
meter display will align with the “0” mark and
the digits display will show “0.0”.
You’re now ready to use the electrometer to mea-
sure charge, current or voltage.
5.
Press the voltage range selector push button to
select the desired voltage range (3, 10, 30, or
100).
The range setting refers to the voltage input
required to produce a full-scale meter deflection
For example, a setting of 30 means that a full scale meter deflection indicates a voltage of 30 volts.
Warning:
1.
Never use the electrometer for measuring potentials more than 100 volts.
2.
Never connect the electrometer to an electrostatics generator, such as a Van de Graff generator
or a Wimhurst machine.
3.
Avoid touching the input leads until you have grounded yourself to an earth ground. A person
walking across a rug on a cool dry day can easily acquire a potential of several thousand volts.
push to turn
ON and OFF
push to select
voltage range
connect
interface
cable here
connect signal
input cable here
connect to
earth ground
ZERO button
push to ground and
remove excess
charges
meter display
digits display
Figure 2: Electrometer Top Panel
(BNC jack)
