The Swain Meter 70 mA Tester for clamp-on DC ammters is a battery powered 70 mA
regulated current source designed to verify the accuracy of direct
current Swain Meters.
The clip to be tested is easily clamped
around the wire loop. A LED is included to show that the battery is
providing current. Be sure to remove the plastic covering the switch
before using.
Before testing, zero the meter using the
zero knob. Put the clip around the wire loop. With the switch depressed,
the LED should be on, showing the battery is good. The current is
generated as long as the switch is depressed. The direction of current
flow is indicated by an arrow on the case. With the arrow engraved on
the clip pointing in the same direction as the arrow on the case, the
meter reads positive 70 mA ± 2 mA.
On the other hand, with the clip turned
over so that its arrow points opposite to that on the case, the reading
on the Swain Meter should be negative 70 mA ± 3 mA. To be accurate, the
wire must not be near the lips or jaws of the clip.
If the Swain Meter does not show 70 mA ±
2 mA, it is not showing the proper current and may need to be returned
to the Swain Meter for repairs.
The 2 "AA" cells should last for at least
4 hours of constant usage, or about 4 months, whichever comes first. It
would be advisable to change batteries at that time.
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