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NI PXI-5404 Calibration Procedure
Calibration Overview
This section describes external calibration and explains why and how often you should calibrate
your modules.
What Is External Calibration?
External calibration is a set of operations that compares the signals generated by a module or a
system to external standards. The result of an external calibration can be used to determine the
output error and can be used to correct the errors in the adjustment process.
The calibration process consists of verification, adjustment, and reverification. During
verification, you compare the measured performance to an external standard of known
measurement uncertainty to confirm that the performance of the module is better than the
published specifications. During adjustment, you correct the generation error of the module by
adjusting the calibration constants and storing the new calibration constants in the onboard
EEPROM. The host computer reads the calibration constants and the software uses them to
compensate for errors and to present a calibrated output to the user. Reverification means
repeating verification after the adjustment process.
Why Should You Calibrate?
The accuracy of electronic components drifts with time and temperature, which can affect
generation accuracy. Calibration restores the NI 5404 to its specified accuracy and ensures that
it still meets National Instruments standards.
How Often Should You Calibrate?
NI recommends performing a complete calibration at least once every year. You can shorten this
interval based on the demands of your application.
Equipment and Other Test Requirements
This section describes the test equipment, test conditions, documentation, and software required
for calibration.
Test Equipment
External calibration requires different equipment for each applicable specification. Refer to
Table 1 for a list of equipment.