Instructions

AP033 Active Differential Probe
34
Adjustment Procedure
Introduction
You can use this procedure to adjust the AP033 Active Differential Probe to meet the
warranted specifications. This procedure should only be performed if the instrument fails
the Performance Verification tests.
If the probe cannot be adjusted to meet the Performance Verification limits, repair may
be necessary.
To ensure instrument accuracy, check the calibration of the AP033 Active Differential
Probe every year. Before calibration, thoroughly clean and inspect this unit as discussed
in the “Cleaning” section.
Completion of each step in the Adjustment Procedure ensures that the differential probe
meets specifications. Some of the adjustments interact with other parts of the circuitry.
Therefore, it is necessary that all adjustments be performed in the order listed. For best
overall instrument performance, make each adjustment to the exact setting, even when
adjustment is within the limits stated in the procedure.
Adequate guard bands were designed into the AP033 Active Differential Probe to ensure
that it will meet or exceed published specifications over the entire operating temperature
range. To continue to meet the environmental specifications, all adjustments must be
performed in a controlled environment with an ambient temperature of 25 ±5 °C. The
AP033 Active Differential Probe must also be at stable operating temperature before
performing adjustments.
CAUTION: The adjustment procedure requires that you remove the probe covers.
These covers are part of the ESD protection system of the AP033 probe. To
protect the probe, perform the entire procedure on a static dissipating work
surface. Wear an anti
-static grounding wrist strap and follow standard static
control procedures.
The probe tip housing provides physical rigidity to the input of the probe. When
the covers are removed, observe extra caution to avoid breaking the probe tip
receptacles, especially when mating the p
robe to the calibration fixture.