36
N2780/81/82/83 User’s and Service Guide
N O T E
•
The output of this unit is terminated internally. Use an
oscilloscope with an input impedance of at least 1 M
or
use the Agilent E2697A impedance adapter.
•
Immediately after powering on the probe, the probe may
be subject to an appreciable offset drift due to the effect
of self- heating. To counteract this, allow the probe to
warm up for about 30 minutes before carrying out
measurement.
•
When performing continuous measurements, it is
necessary to be aware that the offset voltage drifts,
depending on factors such as the ambient temperature.
•
Under certain circumstances, oscillation may occur if the
probe is connected to the N2779A power supply while the
power supply is on. This does not indicate a malfunction.
Oscillation can be stopped and operation restored to
normal by opening and closing the sensor head.
•
Depending on the measured current frequency, some
sound maybe produced by resonance, but has no effect on
measurements.
•
The reading may be affected by the position within the
clamp aperture of the conductor being measured. The
conductor should be in the center of the clamp aperture.
•
When carrying out a measurement, press the opening
lever until the “UNLOCK” indication disappears and check
that the sensor head is properly closed. If the sensor head
is not properly closed, an accurate measurement is not
possible.
•
Accurate measurement may be impossible in locations
subject to strong external magnetic fields, such as
transformers and high- current conductors, or in locations
subject to strong external electric fields, such as radio
transmission equipment. .
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