
Charge Producers and Proof Plane ES-9057C
2
NOTE: The charge producers are designed to be used with the
basic electrometer (ES-9078). They do not produce sufficient
charge for use with a standard electroscope.
The conductive knob on the end of the charge producers and the
proof plane is designed to be used with the Conductive Hollow
Sphere from the PASCO ES-9061 Conductive Shapes apparatus.
You can insert the knob through the hole on the top of the Con-
ductive Hollow Sphere to sample the charge density on the inside
of the sphere.
Other
The conductive disk material is carbon-filled black polycarbon-
ate (about 103). The nonconductive neck is white polycarbon-
ate (about 1014 ).
NOTE: You can then use a PASCO Basic Electrometer and a
Faraday Ice Pail (ES-9042A) to measure the charge density on
the proof plane, as shown in the following illustration.
By touching the proof plane to a surface, it will acquire the same
charge distribution as the surface. By measuring the charge on
the proof plane, the charge density on the surface can be deter-
mined. The greater the charge on the proof plane, the greater the
charge density on the surface where the proof plane made con-
tact.
When the proof plane is touched to a conductor, the proof plane
becomes part of the conductive surface. If the effect on the shape
of the surface is significant, the sampling of the charge density
will not be accurate. Therefore, always touch the proof plane to
the conductor in such a way as to minimize the distortion of the
conductive surface. The following illustration shows the recom-
mended method for using the proof plane to sample the charge on
a conductive sphere.
NOTE: To accurately sample charge density, the conductor should
be considerably larger than the disk of the proof plane and have a
relatively large radius of curvature at the point from which the
sample is taken. However, the proof plane can be used to test for
charge polarity on conductors of any shape.
Technical Support
For assistance with any PASCO product, contact PASCO at:
For more information about the Charge Producers and Proof
Plane and the latest revision of this Instruction Sheet, visit:
www.pasco.com/go?ES-9057C
Limited Warranty For a description of the product warranty, see the
PASCO catalog. Copyright The PASCO scientific 012-07144B Charge
Producers and Proof Plane Instruction Sheet is copyrighted with all rights
reserved. Permission is granted to non-profit educational institutions for
reproduction of any part of this manual, providing the reproductions are
used only in their laboratories and classrooms, and are not sold for profit.
Reproduction under any other circumstances, without the written consent
of PASCO scientific, is prohibited. Trademarks PASCO and PASCO
scientific are trademarks or registered trademarks of PASCO scientific, in
the United States and/or in other countries. All other brands, products, or
service names are or may be trademarks or service marks of, and are
used to identify, products or services of, their respective owners. For more
information visit www.pasco.com/legal.
Electrometer Faraday Ice
Pail
Charged Proof Plane
Signal lead
Ground lead
Address: PASCO scientific
10101 Foothills Blvd.
Roseville, CA 95747-7100
Phone: 916-786-3800 (worldwide)
800-772-8700 (U.S.)
Fax: (916) 786-7565
Web: www.pasco.com
Charged conductive
sphere
Proof plane is tangent
to the surface of the
conductor.
Proof plane is NOT
tangent to the surface
of the conductor.
YES!NO!