PASCO SF-9500A User Manual

Instruction Sheet
for the PASCO
Model SF-9500A

STUDENT GALVANOMETER

Introduction

The PASCO SF-9500A Student Galvanometer is a
rugged, yet sensitive instrument, designed specifically
for student experiments. It has a center-zero meter that
ensures easy determination of polarity, and three
current ranges. A “Push-To-Read” switch protects the
meter during hookup by shunting the current through
an equivalent resistor. When performing a null-current
experiment, such as measuring resistance using a
Wheatstone bridge, it is easy to balance the current
using the 5 mA range, then stepping down through the
lower current ranges to very accurately determine the
point of zero current.

CE

Galvanometer

40

20

SF-9500A

40

20

0

®

5 mA

500 mA

PUSH

TO

READ

50 mA

012-07749A

NOTE: If the position of the meter changes after it is
mechanically aligned, the meter may need to be zeroed
again.

To measure current:

1. Connect the circuit between the negative terminal
of the galvanometer and the red input connector
with a current rating greater than the expected
current.

NOTE: It is a good idea to begin with the 5 mA
range, then step down to the lower ranges as
required. The meter is protected while you make
the connections, because the current does not pass
through the meter. Instead it passes through a
parallel shunt resistor that has the same resistance
as the meter.

2. When the connections are made, and you are ready

0

to measure the current, press and hold the PUSH
TO READ button.

Operation

To zero the meter:

Place the meter in the position in which it will be
used, vertically or horizontally. Disconnect the meter.
Use a small, flat-head screwdriver to turn the zero­adjust screw (located on the meter housing below the
meter) until the meter needle aligns with the zero
mark on the scale.

3. Now read the current on the meter

The current ranges displayed beside the input
connectors refer to the current value that will give a
full-scale meter deflection. For example, a meter
reading of +40 in the 5 mA range indicates a current of
4 mA flowing through the galvanometer. A reading of
–40 indicates that 4 mA of current is flowing in the
opposite direction.

© 2001 PASCO scientific

Student Galvanometer 012-07749A

Limited Warranty

5 mA

500 mA

CIRCUIT

50 mA

Direction of positive

current flow

0

Current flow

Specifications:

Measuring Internal Max Accuracy

range resistance current

± 5 mA 8 W 100 mA 2%

± 500 µA 80 W 100 mA 2%

PASCO scientific warrants the 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 material or workmanship. The
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 improper 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.

± 50 µA 800 W 1 A 2%

Address: PASCO scientific

10101 Foothills Blvd.
Roseville, CA 95747-7100

Phone: [phone]

FAX: [phone]

e-mail: [e-mail]

Web site: www.pasco.com

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