Radio Shack 22-168A - Making Measurements; Understanding Phantom Readings; Measuring High-Voltage Circuits Safely

MAKING MEASUREMENTS
UNDERSTANDING
PHANTOM READINGS
In some DC and AC voltage ranges, when the
probes are not connected to any circuit, the
display might show a phantom reading. This is
normal. The meter’s high input sensitivity pro-
duces a wandering effect. When you connect the
probes to a circuit, accurate readings appear.
MEASURING
HIGH-VOLTAGE CIRCUITS
When you use the meter to check a high-voltage
Circuit, do not try to position both probes at once.
Instead, clamp one’probe to the neutral or ground
lead of the circuit (usually a bare, green, or white
wire in AC wiring circuits) using insulated Slip-
On Alligator Clips (Cat. No. 270-354). Then probe
for voltages with the other probe. This helps pre-
vent you from accidentally touching a hot wire
because you need to concentrate on only one
test probe.
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Warning: Never clamp onto a hot wire, (usually
red, black, or blue in AC wiring circuits.) If you
clamp onto a hot wire and touch the other probe,
you could receive a shock.