Calibrate the RM-4339 using Calibration Executive.

Calibration Executive Procedure Features

Verify Only Verify & Adjust Manual Mode Optional Adjust

Approximate Test Time

60 minutes (verify only)

Test Equipment

The following table lists the test equipment required to calibrate the RM-4339.

Table 151. Test equipment for calibrating the RM-4339
Instrument Recommended Model Requirements
Calibrator Fluke 5520A If this instrument is unavailable, use a calibrator that can provide resistance values in the range of 120 Ω to 1 kΩ with 0.01 Ω resolution, and an accuracy of 90 ppm or better, and can sink 15 mA on the 120 Ω setting, 8 mA on the 350  Ω setting, and 3 mA on the 1 kΩ setting.
Ohm Meter PXI-4070 If this instrument is unavailable, use a 6 1/2-digit DMM with 2-wire resistance measurement capability and resistance accuracy of 80 ppm or better of reading +6 ppm of range for the 100 kΩ range.
8-Channel Universal-Bridge Input Module PXIe-4339 —
Terminal Block Connection Accessory TB-4339/B/C* —
PXI Express Chassis PXIe-1062Q —
Accessory Cable SH96-96-2 The SH96-96-2 is available in 1 meter, 3 meter, and 5 meter lengths. Any of these cable lengths can be used.
RJ50 to Pigtail Cable (x9) NI P/N: 195950-02 An RJ50 cable with a cable wire resistance <0.2 Ω with better than 10% resistance mismatch between individual wires.
Note *The terminal block variants TB-4339, TB-4339B, and TB-4339C differ only in resistance; the measurements are the same regardless of the variant used.

Test Conditions

The following setup and environmental conditions are required to ensure the RM-4339 meets published specifications.

  • Keep connections to the RM-4339 as short as possible. Long cables and wires act as antennas, picking up extra noise that can affect measurements.
  • Verify that all connections to the device, including front panel connections, are secure.
  • Use shielded copper wire for all cable connections to the device. Use twisted-pair wire to eliminate noise and thermal offsets.
  • Maintain an ambient temperature of 23 °C ± 5°C. The device temperature will be greater than the ambient temperature.
    Note The temperature variation of the environment should be kept within 1 °C between measurement of the offset error of the PXIe-4339 and the offset measurement of the RM-4339.
  • Keep relative humidity below 80%.
  • Allow a warm up time for each of the instruments used in this procedure according to the specific instruments operating instructions.
  • Ensure that the PXI/PXI Express chassis fan speed is set to HIGH, that the fan filters are clean, and that the empty slots contain filler panels. For more information, refer to the Maintain Forced-Air Cooling Note to Users document available at ni.com/docs.

Connecting to the RM-4339

Hazardous Voltage Make sure the PXI Express chassis is powered off before you insert a module into the chassis.

For information about the required connections for the SCA Shunt Calibration Resistance Accuracy Verification, Offset Voltage Verification, and Quarter-Bridge Shunt Calibration Accuracy Verification procedures, refer to the RM-4339 Calibration Procedure, available at ni.com/docs.

To minimize the number of verification connection changes, the connections for SCA Shunt Calibration Resistance Accuracy Verification and Quarter-Bridge Shunt Calibration Accuracy Verification can be made simultaneously.

The TB-4339/B/C terminal block used to short all the AI+ and AI- channels to AIGND should be left connected as in the following diagram to avoid having to wire it up each time you run the procedure.

The RM-4339 provides support for up to three PXIe-4339 modules. The 96-pin DIN connectors used to connect the PXIe-4339 to the RM-4339 through the SH96-96-2 cable are located on the rear of the RM-4339 and are labeled A, B, and C. To fully verify the RM-4339, each of the verification procedures in this document must be conducted for each position A, B, and C. Refer to the NI PXIe-4339 and RM-4339 User Guide and Terminal Block Specifications for information about how to install and use the RM-4339.

Device Setup

  1. Install the RM-4339 according to the instructions in the NI PXIe-4339 and RM-4339 User Guide and Terminal Block Specifications.
    Note When multiple PXIe-4339 measurement devices are configured, you may have the option to calibrate multiple RM-4339 terminal blocks in a single session. Because only one measurement device can configured as an instrument for the session, each terminal block must be connected to the selected measurement device during its calibration session.
  2. Configure the hardware using Measurement & Automation Explorer (MAX).
  3. Launch the Calibration Executive procedure and complete the setup wizard.

Calibration Executive guides you through the connections required for calibration.

Test Limit Equations

The following test limits are derived from the published specifications.

Table 152. RM-4339 Test Limit Equations
Equation Type Equation
SCA Shunt Calibration Resistance Accuracy Verification Limits = Nominal Value * (1 ± 0.1%)
Offset Voltage Verification Limits = Test Point ± 10 µV
Quarter-Bridge Shunt Calibration Accuracy Verification

120 Ω quarter completion tolerance = 0.25%

350 Ω and 1 kΩ quarter completion tolerance = 0.15%

50 Ω and 100 kΩ quarter bridge shunt calibration resistor tolerance = 0.1%

  • Therefore:
  • 120 Ω shunt cal accuracy = 0.25% + 0.1% = 0.35%
  • 350 Ω shunt cal accuracy = 0.15% + 0.1% = 0.25%
  • 50 Ω shunt cal accuracy = 0.15% + 0.1% = 0.25%
Equations

The limits for each quarter bridge configuration are calculated as such:

  • 120 Ω

    Limit (V/V) = Nominal Value * (1 ± 0.35%)

  • 350 Ω

    Limit (V/V) = Nominal Value * (1 ± 0.25%)

  • 1 kΩ

    Limit (V/V) = Nominal Value * (1 ± 0.25%)