PASCO ES-9060 Charge, Equipotential and Field Mapper User Manual

Page 22

Model No. ES-9060

Charge, Equipotential, and Field Mapper

Procedure:

1. Connect the Electrometer, outer shield of the Faraday Ice Pail, and

Electrostatics Voltage Source to a common earth ground. Follow the
setup in Figure 3.0. Connect the black lead over the edge of the shield
and the red lead over the edge of the ice pail. Connect the Voltage
Source to the same earth ground as the shield and the Electrometer.

WARNING: To avoid the risk of shock or electrical injury,
always ground your equipment. Before proceeding, follow
the setup in Figure 3.0 and instructions in step 1. To ground

yourself, keep one hand on the upper edge of the shield of the Faraday
Ice Pail or on the earth-ground lead.

2. Zero the Electrometer to remove any residual charge.

3. Place a sheet of 30 x 46 cm conductive, black paper on the

corkboard. Connect this paper to ground.

4. Place the “point charge disk” in the center of the paper with the

plastic insulator between the paper and disk. Connect the disk to a
2000V DC or higher power supply (See Figure 3.0).

5. Ground yourself by placing one hand or finger on the shield of the

ice pail or the ground connector.

6. Use the Proof Plane to sample the charge density about every 3

centimeters on a line from the disk to one of the corners of the
paper.

Remember, any wires used to connect the paper shape to the power
supply must also affect the charge distribution. Therefore, exercise
extreme care in the placement of the wires.

Questions:

a) Does there seem to be a ratio between the distance of the proof plane

from the “point charge disk” and the charge density? What might
this relationship be?

b)Would the charge density be different if the conductive paper sheet

were infinite in size?