Calibrate the NI-9227 using Calibration Executive.

Calibration Executive Procedure Features

Verify Only Verify & Adjust Manual Mode Optional Adjust

Approximate Test Time

Verify OnlyVerify & Adjust
3 minutes 8 minutes

Test Equipment

The following table lists the test equipment required for calibrating NI-9227 modules.

Table 52. Test equipment for calibrating the NI-9227
Instrument Recommended Model Where Used Requirements
Calibrator Fluke 5520A Accuracy,

Adjustment

 Use a high-precision current source with an accuracy ≤100 ppm.
Function Generator NI 5421 Gain Matching,

Phase Matching

 Use a function generator with an output impedance of 50Ω capable of sourcing both 1 kHz and 20 kHz ±10 Vpk AC sinusoidal signals with amplitude uncertainty of ±10% to a 50Ω load.
Termination Resistor — Gain Matching,

Phase Matching

 50 Ω, 1 W, ±5%
Chassis cDAQ-9178 All —
Note To avoid an error, the NI-9227 calibration procedure requires that you set current limits of the calibrator to more than ±5 Amps.

Test Conditions

The following setup and environmental conditions are required to ensure the NI-9227 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.
  • Verify that all connections to the device are secure.
  • Use shielded copper wire for all cable connections to the device. Use twisted-pairs 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-9227 measurement circuitry is at a stable operating temperature.

Device Setup

  1. Make sure the cDAQ-9178 power source is not connected.
  2. Connect the cDAQ-9178 to the system safety ground.
    1. Attach a ring lug to a 14 AWG (1.6 mm) wire.
    2. Connect the ring lug to the ground terminal on the side of the cDAQ-9178 using the ground screw.
    3. Attach the other end of the wire to the system safety ground.
  3. Install the module in slot 8 of the cDAQ-9178 chassis. Leave slots 1 through 7 of the cDAQ-9178 chassis empty.
  4. Connect the cDAQ-9178 chassis to your host computer.
  5. Connect the power source to the cDAQ-9178 chassis.
  6. Launch Measurement & Automation Explorer (MAX).
  7. Right-click the device name and select Self-Test to ensure that the module is working properly.

Test Limit Equations

The following test limits are derived from the published specifications.

Table 53. NI-9227 Test Limit Equations
Equation Type Equation
Accuracy TestLimits = TestValue ± (TestValue * GainError (% of Reading) + OffsetError)
  • Offset: 3.535mA
  • Gain: 0.1%
Gain Matching ±0.13 dB Max
Phase Matching ±0.1 Deg/kHz Max