3b-scientific Electroscope User Manual download pdf

Instruction Sheet

3B SCIENTIFIC® PHYSICS

U17250 Electroscope

6/03 ALF

The device is used for an introduction into the funda-

mentals of electrostatics and for displaying DC and AC

voltages as well as demonstrating the operating prin-

ciples of high voltage meters according to Braun.

1. Safety instructions

• Make sure that the insulator is always clean and

dry. If necessary use alcohol or spirits for cleaning.

• At high humidity and after transporting the unit

from a cool room into a warmer one, dry the elec-

troscope in a stream of hot air (e.g. a hair dryer).

2. Description, technical data

The electroscope consists of a metal baseplate on which

the iron shielding ring for defined field distribution is

mounted. The iron ring is equipped with a 4-mm socket

for earthing purposes. The support for needle with

pivot bearing is attached electrically insulated to the

shielding ring. The pointer is suspended asymmetri-

cally and so its weight delivers the restoring moment.

Inside the electrically conductive insulator at the up-

per part of the device there is a 4-mm socket for mount-

ing the sphere and capacitor plate.

For demonstration experiments the electroscope is suit-

able for shadow projection using a point source light.

Diameter: 130 mm

2.1 Scope of supply

1 Electroscope

1 Sphere with 4-mm plug

1 Capacitor plate with 4-mm plug

1 Capacitor plate on insulating rod

3. Operation

The electroscope is charged using friction rods stati-

cally charged by various friction-inducing materials

(e.g. U11053), or using a high-voltage power supply unit

(e.g. U21060).

3.1 Charging up the electroscope by touching it

with a statically charged body

• Attach the sphere or capacitor plate to the elec-

troscope.

• Rub the friction rod with the suitable material (PVC

or acrylic rods e.g. with plastic foil).

• Touch the sphere or capacitor plate with the

charged rod. The pointer deflects.

• Remove the friction rod, the pointer remains de-

flected.

• Touch the sphere with your hand. The pointer re-

turns to normal.

• When a high-voltage power supply is used then

attach the capacitor plate to the positive pole of

the power supply unit. Connect the negative pole

1 Sphere with 4-mm plug

2 Insulator

3 Shielding ring

4 Baseplate

5 Capacitor plate with 4-mm plug

6 Capacitor plate on insulating rod

7 4-mm socket

8 Support with pointer

1 2

Summary of Contents

Page 1 - U17250 Electroscope

3Instruction Sheet3B SCIENTIFIC® PHYSICSU17250 Electroscope6/03 ALF®The device is used for an introduction into the funda-mentals of electrostatics an

Page 2

4with the earth socket on the power supply andwith the earth socket on the electroscope.• Use a charge spoon (e.g. U11051) to draw a chargefrom the ca