Appendix B: Calibration
Model 2657A High Power System SourceMeter® Instrument Reference Manual
B-4
2657A-901-01 Rev. B/December 2012
Source limit calculations
As an example of how to calculate source verification limits, assume you are testing the Model 2657A
200 V DC output range using a 180 V output value. Using the one-year accuracy specification for the
200 V range DC output of ± (0.03% of 50 mV offset), the calculated output limits are:
Output limits = 180.0 V ± [(180.0 V
×
0.03%) + 50 mV]
Output limits = 180.0 V ± (0.054 V + 0.050 V)
Output limits = 180.0 V ± 0.104 V
Output limits = 179.896 V to 180.104 V
Source limits for current are calculated in the same way but using the Model 2657A instrument's
current source specifications.
Measurement limit calculations
Measurement limits are calculated in the same way as the source limits, except that the limits are
calculated with respect to the measurement of the external reference instrument. For example,
suppose that the Model 2657A is programmed to source 180.0 V and the external precision DMM
measures 179.986 V. Using the one-year accuracy specification for the 200 V DC range
measurement of ± (0.025% of 50 mV offset), the calculated measurement limits are:
Measurement limits = 179.986 V ± [(179.986 V
×
0.025%) + 50 mV]
Measurement limits = 179.986 V ± (0.0449965 V + 0.050 V)
Measurement limits = 179.986 V ± 0.0949965 V
Measurement limits = 179.891 V to 180.081 V
Measurement limits for current are calculated in the same way but using the Model 2657A
instrument's current measurement specifications.
Restoring factory defaults
Before performing the verification procedures, restore the instrument to its factory front panel (bench)
defaults as follows:
1. Press
the
MENU
key.
2. Scroll to the
SETUP
menu item (by turning the navigation wheel
), and then press the
ENTER
key.
3. Scroll to the
RECALL
menu item, and then press the
ENTER
key.
4. Scroll to the
INTERNAL
menu item, and then press the
ENTER
key.
5. Scroll to the
FACTORY
menu item.
6. Press
the
ENTER
key to restore defaults.
Performing the verification test procedures
Test summary
Perform the following verification tests to make sure the instrument is operating within specifications:
•
(on page B-6)
•
(on page B-8)
•
(on page B-9)
•
Summary of Contents for 2657A
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