12
N2780/1/2/3B User’s Guide
Making Measurements
9
Press the probe’s demagnetizing switch (
DEMAG
).
10
Turn the probe’s zero adjustment dial to adjust the trace to the zero position.
NOTE
N2782/3B probes have a coarse adjustment trimmer. If zero adjustment
is not possible on an N2782/3B probe, turn the coarse adjustment
trimmer to bring the trace within the range of adjustment by the zero
adjustment dial. See
on page 8 for the location of the coarse
adjustment trimmer. To avoid damaging the trimmer, do not force too
much while adjusting it. Use a screwdriver made of non-conductive
material such as ceramic, preferably with a flathead tip, 0.4 mm thick,
1.8 mm wide, and 10 mm or longer in length.
Measurement
WARNING
Check that the system is safe and that the preparations described in
on page 13 have been carried out.
11
Press the opening lever to open the sensor head.
12
Align the sensor so that the probe’s current direction indication corresponds to
the direction of current flow through the conductor to be measured. Also, align
the clamp so that the conductor is in the center of the sensor aperture.
13
Press the opening lever on the sensor head until the
UNLOCK
indication
disappears. Check that the opening lever is firmly locked and the sensor head
securely closed.
14
If you are using an N2780/1B current probe, set the oscilloscope to the
following settings:
Input Impedance: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 M
Ω
Attenuation Ratio: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100:1
Units: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Amperes
15
If you are using an N2782/3B current probe, set the oscilloscope to the
following settings:
Input Impedance: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 M
Ω
Attenuation Ratio: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10:1
Units: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Amperes
