Instruction manual

012-05258B
2
➤ NOTE: You can then use an electrometer and
a Faraday ice pail (ES-9042A) to measure the
charge density on the proof plane, as shown in
the following illustration.
Electrometer
Faraday ice pail and shield
Ground lead
Insert charged proof
plane into Faraday
ice pail
Signal lead
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 determined. The greater
the charge on the proof plane, the greater the charge
density on the surface where the proof plane made
contact.
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 conduc-
tor in such a way as to minimize the distortion of the
conductive surface. The following illustration shows
the recommended 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 planes
can be used to test for charge polarity on conduc-
tors of any shape.
Other
The conductive disk material is carbon filled black
polycarbonate (about 10
3
Ω). The non-conductive neck
is white polycarbonate (about 10
14
Ω).
Limited Warranty
PASCO scientific warrants this product to be free from
defects in materials and workmanship for a period of
one year from the date of shipment to the customer.
PASCO will repair or replace, at its option, any part of
the product which is deemed to be defective in mate-
rial or workmanship. This warranty does not cover
damage to the product caused by abuse or improper
use. Determination of whether a product failure is the
result of a manufacturing defect or improper use by the
customer shall be made solely by PASCO scientific.
Responsibility for the return of equipment for warranty
repair belongs to the customer. Equipment must be
properly packed to prevent damage and shipped
postage or freight prepaid. (Damage caused by im-
proper packing of the equipment for return shipment
will not be covered by the warranty.) Shipping costs
for returning the equipment, after repair, will be paid
by PASCO scientific.
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YES!
charged
conductive
sphere
Surface of the proof plane disk
IS tangent to the surface
of the conductor.
NO!
Surface of the proof plane disk
IS NOT tangent to the surface
of the conductor.