Calibrate the NI-9238 using Calibration Executive.

Calibration Executive Procedure Features:

Verify Only Verify & Adjust Manual Mode Optional Adjust

Approximate Test Time

Warm-upVerify & Adjust
10 minutes 6 minutes

Test Equipment

The following table lists the test equipment required for calibrating NI-9238 modules.

Table 64. Test equipment for calibrating the NI-9238
Instrument Recommended Model Requirements
Calibrator Fluke 5500A If this instrument is unavailable, use a high-precision voltage source with an accuracy of ≤60 ppm and offset error ≤6 µV.
Chassis cDAQ-9178 —

Test Conditions

The following setup and environmental conditions are required to ensure the NI-9238 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-9238 measurement circuitry is at a stable operating temperature.

Device Setup

  1. Install the NI-9238 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-9238 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-9238 Calibration Procedure.

Table 65. NI-9238 Test Limit Equations
Equation Types Equation
Accuracy Verification AccuracyVerificationLimit = TestValue ± (TestValue * GainError + Range * Offset Error)