CEM DT-5302, Instruction Manual

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3
Safety symbols:
Caution refer to this manual before using the meter.
Dangerous voltages.
Meter is protected throughout by double insulation or
reinforced insulation.
When servicing, use only specified replacement parts.
CE
Comply with EN-61010-1
II
．
OPERATING PRINCIPLE
Suppose we wished to measure the resistance of some component
located a significant distance away from our ohmmeter. Such a
scenario would be problematic, because an ohmmeter measures
all
resistance in the circuit loop, which includes the resistance of the
wires (R
wire
) connecting the ohmmeter to the component being
measured (R
subject
):
Usually, wire resistance is very small (only a few ohms per hundreds
of feet, depending primarily on the gauge (size) of the wire), but if
the connecting wires are very long, and/or the component to be
measured has a very low resistance anyway, the measurement error
introduced by wire resistance will be substantial.