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Appendix A
Calculating D/A Converter Accuracy
Introduction
This appendix shows how D/A Converter (DAC) accuracy, HP 3458A
multimeter measurement uncertainty, and test accuracy ratio (TAR) values
are defined and calculated for the performance verification tests for the
HP E1328A DAC.
See Table 4-2, "Performance Test Record for the HP E1328A DAC" for
1-year specification values for DAC accuracy, 1-year measurement
uncertainty values for the HP 3458A multimeter, and associated DAC test
accuracy ratios (TARs).
NOTE
DAC accuracy, multimeter measurement uncertainty, and test accuracy
ratios in Table 4-2 are valid ONLY for the specified test conditions and
assumptions described in this manual. For the test conditions described, in
TARs exceed 4:1
DAC Accuracy
Definition
DAC accuracy is the expected accuracy of the measurement due ONLY to
the D/A Converter. The "Low Limit" entry in Table 4-2 is the lower (-)
value of DAC accuracy, while the "High Limit" entry is the upper (+) value
of DAC accuracy.
Measurement
Uncertainty Definition
Measurement Uncertainty is the expected accuracy of the HP 3458A
multimeter for specified conditions. This value is shown in the
"Measurement Uncertainty" column of Table 4-2. See the HP 3458A
Multimeter Operating, Programming, and Configuration Manual for
additional information on calculating HP 3458A multimeter measurement
uncertainty.
Test Accuracy Ratio
(TAR) Definition
Test Accuracy Ratio (TAR) is the ratio of DAC accuracy to HP 3458A
multimeter measurement uncertainty. For the HP E1328A DAC
performance tests, Test Accuracy Ratio = (High Limit value - Test Output
value)/Measurement Uncertainty value. This value is shown in the "Test
Accuracy Ratio (TAR)" column of Table 4-2.
Appendix A Calculating D/A Converter Accuracy 55