AFX SERIES® OPERATION MANUAL
SECTION 11: CALIBRATION
Entire Contents Copyright
2016 by Pacific Power Source, Inc. (PPS) • All Rights Reserved • No reproduction without written authorization from PPS.
AFX Series Power Source Operation Manual
Page 261 of 274
11
Calibration
11.1
Calibration Interval
All units are shipped new from the factory with NIST traceable calibration. It is recommended to
perform an annual calibration check to ensure performance to specifications. Under normal
circumstances, no adjustment will be needed but can be made as part of the user calibration
coefficients.
11.2
Closed Case User Calibration
This section covers routine calibration that can be performed by the user. User calibration does
not affect the factory set calibration coefficients that were determined and set at the time of
shipment to ensure compliance with published specifications. Rather, user calibration can be
used to obtain enhanced performance at typical operating conditions by adjusting these user
coefficients at these conditions. For example, if the unit is used primary for testing 400Hz, three
phase 115V L-N three phase operation, calibrating the user coefficients to these operating
conditions against an external precision reference can provide enhanced performance versus
published specifications (See Section 4, “Technical Specifications”).
Since user calibration does not affect factory calibration settings, resetting all user calibration
coefficients does not invalidate the units specified performance and it can be used with all user
coefficients reset as needed.
Note:
There are no analog adjustment pots in this instrument and all calibration can be
performed from the front panel or over one of the digital control interfaces.
11.3
Equipment Required
The following list of equipment or equivalent is required to perform routine annual calibration
of the instrument. Current sensor options are determined by need for AC, DC or both.
Item
Make
Model
Notes
1
Keysight
34465A
6 ½ Digit DMM or equivalent
2
Current Transformer
(AC Only)
Pearson
Model 110, 65 Arms Max. 5000Apk Max. 0.1V/A +1/-
0%, Rout = 50 Ohms
http://www.pearsonelectronics.com/products/current-
3
Current Sensor
(AC and DC)
LEM
IT 200-S ULTRASTAB, 200 A, ± 0.0086% Accuracy, 50
kHz BW or equivalent.
http://www.lem.com/hq/en/component/option,com
_catalog/task,displaymodel/id,71.36.44.000.0/
Requires precision burden resistor for direct DMM
measurements, i.e. Reidon, P/N
SM10-100RX, 0.01% 100 Ohm, 0.3W, qty 2 or 3 in
parallel for 50 Ohm or 33.3 Ohm burden
https://www.digikey.com/product-detail/en/riedon/SM10-
4
Current Shunt
(DC)
Ohm-Labs
CS-200, Shunt, 1 mOhm, 0.02% Accuracy @ DC to
50/60 Hz or equivalent
Table 11-1: Required Calibration Equipment
Summary of Contents for 3120AFX
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