User's Manual

ES-9080A 012-07227G Basic Electrostatics System

day can cause charge to easily build up in any moving object, including people. Minimize

all movement when demonstrating on a very dry day.

• Practice - Nothing can ruin the instructive value of a demonstration more than failure due to

a demonstrator’s unfamiliarity with the equipment and procedure.

Before presenting a series of electrostatic demonstrations, the student (and of course, the

instructor) should be made aware of the following:

• The theory and use of the Faraday Ice Pail. (This is adequately covered in the “Equipment

Description” section and in Demonstration 1.)

• The possible distortion of charge density due to improper use of the proof plane. (See the

“Equipment Description” section.)

• Residual charge may build up in the plastic insulator between the handle and disk of the

proof plane and charge producers. Make sure to ground these parts before any experiment.

• The capacitance of the electrometer must be considered when calculating the magnitude of

a charge from the voltage reading of the electrometer. (See Demonstration 3 for the

procedure necessary to determine the electrometer’s capacitance.)

By following the above principles and by practicing, the demonstrator should have a high

degree of success with the demonstrations and find their educational effect of great value.

Equipment Description

Electrometer (ES-9078A)

The Model ES-9078A Electrometer is a voltmeter used for direct measurements of voltage

and indirect measurements of current and charge. Because of its high (“infinite”) impedance

of 10

 it is especially suited for measuring charge in electrostatic experiments. It has a

sensitivity nearly one thousand times that of a standard gold-leaf electroscope, a center-zero

meter that directly indicates charge polarity, and a digits display. The electrometer measures

charges as low as 10

-11

coulombs.

The electrometer includes a signal input cable (shielded), a banana plug patch cord, a signal

output (interface) cable, and a grounding cable (for use with the ES-9079 Basic Variable

Capacitor).