Valhalla 2300, Operation Manual

Page: 56 / 115

SECTION VIII CALIBRATION PROCEDURE
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8-1. General
This section provides calibration procedures
for the 2300 Series Digital Power Analyzers.
Two calibration procedures are included.
First, the Routine Calibration of Section 8-4
should be performed at regular intervals
(annually is recommended) to ensure that full
instrument accuracy is maintained. The other,
referred to as Post-Maintenance Calibration,
need be performed only after repair or
component replacement.
8-2. Procedure Notes
Calibration should be performed with the top
and bottom covers installed except when
making adjustments requiring their removal.
It is recommended that the unit be allowed
two hours for warm-up prior to calibration to
achieve temperature stabilization. Maximum
thermal stability may be achieved through the
use of a calibration cover (Valhalla Stock
#04-10749). This item allows adjustments to
be made without having to repeatedly raise
and lower the top cover.
A shorthand notation is used in the two
procedures to identify the location of the
calibration adjustments. The adjustments on
the signal processing boards are identified
φ
A,
φ
B, and
φ
C. For example, the calibration
step using R3 on the phase A signal
processing board is noted as
φ
AR3. The main
board is identified in a similar manner e.g.
MBR3.
The locations of the adjustments are shown on
drawings 2300-600 for the signal processing
board and 2300-601 for the main board.
8-3. Required Test
Equipment
The following test equipment is
required for calibration of the 2300 Series of
Digital Power Analyzers:
1) AC Voltage Calibrator: 1V to 600V,
±0.03% Accuracy (Valhalla 2703 or
equivalent).
2) AC Voltage & Phase Calibrator: 0 to 2V,
±0.03% Accuracy (Valhalla 2705 or
equivalent).
3) AC Transconductance Amplifier: 0.1A to
100A, ±0.25% Accuracy (Valhalla 2555A
or equivalent).
4) DC Voltmeter with DC Accuracy of
±0.3% or greater.
8-4. Routine Calibration
This procedure should be performed at regular
intervals to ensure specified instrument
accuracy. The procedure must be performed
in its entirety and in the order given. Skipping
steps or performing them out of order may
cause the entire instrument to be out of
calibration. Calibration adjustments are
accessed by removing the 5 screws in the
rectangular top cover of the instrument. This
cover should be kept in place except during
adjustment to achieve maximum thermal
stability.
When calibrating the 2300L or 2301L, reduce
all of the voltage inputs to one-tenth the value
given. In all steps, the voltage and current
calibrator frequencies should be set to 100Hz.
8-4-1. Voltage Calibration