barfield 101-00220, User Instruction Manual

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2471F INSTRUCTION MANUAL
56-101-00220-B CH. 1
09 / 23 / 08 Page 5 of 13
CHAPTER 1: PRODUCT DESCRIPTION
1. GENERAL
(1) The 2471F (Fig. 4) is a self-contained, battery operated, high potential megohmmeter.
Test potentials of 100, 200, and 500 volts DC are selectable by a panel switch. Current
limiting circuitry provides safe, ABSOLUTELY SHOCK-PROOF operation.
(2) A single four inch meter scale, increasing from zero at the left to infinity at the right, is
incremented from .5 to 1,000 megohms. A pushbutton on the high potential test probe
provides for conveniently activating the instrument. Flashlight type batteries are used,
and a self-contained battery test is incorporated. Solid-state circuitry provides the
means for size reduction, high sensitivity, and dependability. The meter is a rugge-
dized taut-band suspension type, which eliminates the need for pivots and jewels. The
high potential probe is shield-guarded so that stray leakage through lead insulation will
not affect the measurement accuracy.
(3) The output current of the 2471F is limited to a maximum of 30 microamperes even at
the 500 volt test potential. This current is well below human sensibility, so that there is
no sensation of current if the bare probes are touched with the tester activated. This
current limiting prevents damage to any circuitry or components that can withstand the
applied voltage, and prevents additional damage to a circuit that exhibits any insulation
deterioration.
(4) The 2471F is also protected from damage due to inadvertently connecting the probes
across an energized circuit. AC or DC voltages up to 300 volts can be safely applied.
Figure 4: General View of the Megohmmeter 2471F