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National Instruments Corporation
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NI PXI-4070 Calibration Procedure
Calibration Overview
The complete calibration process for the NI 4070 consists of verifying all
modes with the test limits provided and adjusting the calibration
coefficients for all modes. Frequency is the only mode that does not require
adjustment. Reverifying all modes after adjustments ensures that the
adjustment procedures were performed correctly.
National Instruments can perform stringent in-house calibration of the
NI 4070 and can generate either a basic or a detailed calibration certificate
for you. Visit
ni.com/calibration
for more information on calibration
certificates. This document is provided for those who wish to perform the
calibration procedure themselves.
What Is Calibration?
Calibration is a set of operations that compares the values indicated by a
measuring instrument or measuring system to the corresponding values
realized by external standards. The result of a calibration can be used to
determine the measurement error and can correct for it in the adjustment
process.
The calibration process consists of verifying, adjusting, and reverifying a
device. During verification, you compare the measured performance to an
external standard of known measurement uncertainty to confirm that the
product meets or exceeds specifications. During adjustment, you correct
the measurement error of the device by adjusting the calibration constants
and storing the new calibration constants in the EEPROM.
Normally, the calibration sequence is as follows:
1.
Verify the NI 4070 using the 2-year accuracy limits (or the 90-day
accuracy limits if it has been externally calibrated within that time).
2.
Adjust the NI 4070.
3.
Reverify the NI 4070 using the 24-hour accuracy limits (or the 2-year
accuracy limits when the 24-hour limits are not specified).
Why Should You Calibrate?
Properties of the electrical components responsible for gain and offset
errors may drift with time, temperature, and mechanical stress. Calibration
is required to compensate for this drift and ensure that you, as a user, are
confident that any measurements you make meet NI 4070 specifications.
