Calibrate the NI-9237 using Calibration Executive.

Calibration Executive Procedure Features

Verify Only Verify & Adjust Manual Mode Optional Adjust

Approximate Test Time

6 minutes

Test Equipment

The following table lists the test equipment required for calibrating NI-9237 modules.

Table 62. Test equipment for calibrating the NI-9237
Instrument Recommended Model Requirements
Calibrator Fluke 5700A If this instrument is unavailable, use a high-precision voltage source with an accuracy of at least 10 ppm and an output impedance of ≤ 50 Ω.
DMM NI 4070 If this instrument is unavailable, use a multiranging 6 1/2-digit DMM with an accuracy of at least 40 ppm.
Chassis cDAQ-9178 —
Cable RJ-50 cable —
Bridge Completion Accessories NI 9949, 350 Ω resistors Use one NI 9949 screw terminal accessory and two 350 Ω resistors with at least 1% tolerance.

Test Conditions

The following setup and environmental conditions are required to ensure the NI-9237 meets published specifications.

  • Keep connections to the device as short as possible. Long cables and wires act as antennas, picking up extra noise that can affect measurements.
  • 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.
  • Keep relative humidity below 80%.
  • Allow a warm-up time of at least 10 minutes to ensure that the NI-9237 measurement circuitry is at a stable operating temperature.

Device Setup

  1. Install the NI-9237 in slot 8 of the cDAQ-9178 chassis. Leave slots 1 through 7 on the cDAQ-9178 chassis empty.
  2. Configure the hardware using Measurement & Automation Explorer (MAX).
  3. Launch the Calibration Executive procedure and complete the setup wizard.
Note If the NI-9237 module fails after calibration, return it to NI for repair or replacement.

Test Limit Equations

The following test limits are derived from the published specifications found in the NI-9237 Calibration Procedure.

Table 63. NI-9237 Test Limit Equations
Equation Type Equation
Accuracy TestLimits = TestValue ± (TestValue * GainError + OffsetError)