National Instruments NI 4070/4072 6 1/2-Digit FlexDMM Calibration Procedures

NI 4070/4072 Calibration Procedure 6 ni.com

• Clean any oxidation from the banana plugs on the Fluke 5440 cables

before plugging them into the binding posts of the calibrator or the

banana plug connectors of the NI 4070/4072. Oxidation tarnishes the

copper banana plugs so that they appear dull rather than shiny and

leads to greater thermal EMF.

• Keep the blue banana plugs on the Fluke 5440 cables connected to the

VGUARD binding post of the calibr ator at all times.

• Prevent the cables from moving or vibrating by taping or strapping

them to a nonvibrating surface. Movement or vibration causes

triboelectric effects that can result in measurement errors.

Calibration Procedures

The calibration process includes the following steps:

1. Initial Setup—Set up the test equipment.

2. Verification Procedures—Verify the existing operation of the device.

This step confirms whether the device is operating within its specified

range prior to calibration. Figure4 shows the procedural flow for

verification.

3. Adjustment Procedures—Submit the device to NI for a factory

calibration to adjust the calibration constants. Figure 5 shows the

procedural flow for adjustment.

4. Reverification—Repeat the verification procedure to ensure that the

device is operating within its specifications after adjustment.

These steps are described in more detail in the following sections.

Note In some cases, the complete calibration procedure may not be required. Refer to

Appendix A: Calibration Options for more information.

Initial Setup

Note This section is necessary for pre-adjustment verifications only. If you are performing

a post-adjustment verification, skip the setup and go directly to the Verifying DC Voltage

section.

To set up the test equipment, complete the following steps:

1. Remove all connections from the four input banana plug connectors on

the NI4 070/4072.

2. Verify that the calibrator has been calibrated within the time limits

specified in the Required Test Equipment section, and that DC zeros

calibration has been performed within the last 30 days. Consult the

Contents

Main CALIBRATION PROCEDURE NI 4070/4072 6-Digit FlexDMM Contents Conventions Software Requirements Documentation Requirements Calibration Function Reference Password Calibration Interval Test Equipment Required Test Equipment Requirements for All NI 4070/4072 Devices Additional Requirements for the NI 4072 Optional Test Equipment Test Conditions Calibration Procedures Initial Setup Verification Procedures Verifying DC Voltage Page NI 4070/4072 Calibration Procedure 10 ni.com Figure 1. Cable Connections for Voltage and 2-Wire Resistance niDMM_SetAttributeViReal64 with the following parameters: Attribute_ID = Attribute_Value = NIDMM_VAL_GREATER_THAN_10_GIGAOHM 1 NI4070/4072 2 Fluke 5700A/5720A Calibrator 3 Fluke 5440 Cable Table 1. Fluke 5440 Cable Connections BananaPlug Connector (NI4070/4072) Banana Plug Color (Fluke 5440Cable) Page Page Page Page Verifying AC Voltage Page Page Page Page Page Page Verifying 4-Wire Resistance Page Verifying 2-Wire Resistance Page Page Page Page Page Verifying DC Current Page Page Verifying AC Current Verifying Frequency Page Page Verifying Capacitance and Inductance (NI 4072 Only) Page Page Page Adjustment Procedures Setting Up the Test Equipment Adjusting DC Voltage and Resistance Page Page Page Page Page Adjusting AC Voltage (AC- and DC-Coupled) Modes Page Page Page Table 13. niDMM_CalAdjustACFilter Parameters (Continued) Adjusting Current Modes Page Page Adjusting Capacitance and Inductance (NI 4072 Only) Page Completing the Adjustment Procedures Verification Limits DC Voltage AC Voltage Table 16. NI 4070/4072 AC Voltage Verification Limits Table 15. NI 4070/4072 DC Voltage Verification Limits (Continued) Table 16. NI 4070/4072 AC Voltage Verification Limits (Continued) 4-Wire Resistance Note Tolerances are provided for 4-wire resistance instead of absolute limits because the limits depend on the actual resistance value output by your calibrator. 2-Wire Resistance Note Tolerances are provided for 2-wire resistance instead of absolute limits because the DC Current AC Current Table 19. NI 4070/4072 DC Current Verification Limits Table 20. NI 4070/4072 AC Current Verification Limits Table 18. NI 4070/4072 2-Wire Resistance Verification Tolerances (Continued) Frequency Capacitance and Inductance Note Because the actual capacitance verification values can differ from the following values, Table22 provides tolerances that correspond to the NI 4072 accuracy specifications Table 21. Frequency Limits Appendix A: Calibration Options Page Figure 4. Verification Procedures Flowchart NI 4070/4072 Calibration Procedure 66 ni.com Figure 5. Adjustment Procedures Flowchart National Instruments Corporation 67 NI 4070/4072 Calibration Procedure Where to Go for Support