User's Manual

NI 4070/4072 Calibration Procedure 4 ni.com
Calibration Interval
The accuracy requirements of your measurement application determine
how often you should calibrate the NI 4070/4072. NI recommends
performing a complete calibration at least once every two years. NI does
not guarantee the absolute accuracy of the NI 4070/4072 beyond this
two-year calibration interval. You can shorten the calibration interval based
on the demands of your application. Refer to Appendix A: Calibration
Options for more information.
Test Equipment
This section describes the required and optional equipment for calibration.
Required Test Equipment
Requirements for All NI 4070/4072 Devices
The following equipment is required for calibrating the NI 4070/4072:
• Fluke 5700A multifunction calibrator calibrated within the last
90 days, or a Fluke 5720A multifunction calibrator calibrated within
the last year
• Two sets of Fluke 5440 low thermal electromotive force (EMF) copper
cables
• Pomona 5145 insulated double banana plug shorting bar (or another
means of creating a short with low thermal EMF (≤150 nV) across the
HI and LO input banana plug connectors on the NI 4070/4072)
• Two Pomona B-4 banana-to-banana patch cords (cables) or similar
banana-to-banana cables with length not to exceed 4 in.
• National Instruments PXI chassis and controller, or a personal
computer (PC) with an available slot for the NI 4070/4072
Additional Requirements for the NI 4072
The following equipment is required for calibrating the capacitance and
inductance modes of the NI 4072:
•25Ω, 125 Ω, 5kΩ, and 100 kΩ resistors with thermal drift ≤5ppm/°C
and tolerance ≤1%. The distance between the resistor leads and the
NI 4072 terminals should be ≤1 in.
• Verification capacitors calibrated to at least four times the accuracy of
the NI 4072, with temperature coefficients ≤250 ppm/°C. The values
of the verification capacitors should cover the complete capacitance
range. NI suggests using traceable capacitor standards with values
≥10% of full range for all ranges, except the 300 pF range. For the