Monitoring the Temperature of EIS Tests and ACIR Tests

During EIS tests and ACIR tests, monitoring the temperature allows you to determine at which temperatures your test results are valid.

Introduced in Battery Cell Quality Toolkit 2025 Q3

To monitor the temperature during an EIS test or an ACIR test, use <Test type> Test with Temperature.vi. If the temperature is outside the limits that you define, the Battery Cell Quality Toolkit displays a warning.
Before you begin, create a compensation file that includes temperature data. The temperature data you use in the compensation file must match the temperature data you input in <Test type> Test with Temperature.vi.

Equipment

  • PXIe-4139
  • PXIe-4353
  1. Use the NI Example Finder to open <Test type> Test with Temperature.vi.
    1. In the LabVIEW window, select Help » Find Examples.
      The NI Example Finder window loads.
    2. Select Toolkits and Modules » Battery Cell Quality » <Test type> Test with Temperature.vi.
      The front panel of the VI loads.
  2. On the front panel of the VI, select the SMU resource from the HW Resource Name and Channels control.
    Note NI supports the PXIe-4139 (40 W) and PXIe-4139 (20 W) SMUs.
  3. Optional: If you want the SMU to perform self-calibration, enable self-calibration on the front panel.
    Note You must disconnect the DUT during self-calibration. If the DUT is connected to the SMU during self-calibration, an error occurs.
  4. Enter <Test type> Test Parameters.
    All ACIR tests run at 1000 Hz, so frequency is not a configurable parameter in ACIR Test with Temperature.vi.
    OptionDescription
    Enter the test parameters for an EIS test.
    1. Configure the Frequency Sweep Characteristics. Each entry on the Frequency Sweep Characteristics array defines the parameters that the VI uses to generate a sine wave. Refer to Configuring the Frequency Sweep Characteristics for EIS Measurements for more information about each parameter.
      1. Select the number of tests.
      2. Select the Frequency (Hz). The frequency is limited by the number of arrays you selected.
      3. Select the Current Amplitude (A).
      4. Select the Number of Periods.
    2. Select the Voltage Limit Hi (V).
    3. Select the Nominal DUT Voltage (V).
    4. Select the Compensation Method.
    5. Select the Power Line Frequency.
    Enter the test parameters for an ACIR test.
    1. Select a Nominal DUT Voltage (V).
    2. Select a Voltage Limit Hi (V).
    3. Select a Current Amplitude (A).
    4. Select a Number of Periods.
    5. Select a Compensation Method.
    6. Select a Power Line Frequency.
  5. Select the Temperature Data parameters.
    Note Select the same Temperature Data parameters that you selected when you generated the compensation file.
    1. Select the Thermocouple Resource Name.
      NI recommends using the PXIe-4353.
    2. Select the CJC source.
      If you use the PXIe-4353, NI recommends using the Built-In option for cold junction compensation (CJC). The built-in CJC uses an internal temperature sensor that is located at the terminal block of the connector device. The temperature sensor measures the cold junction temperature (TCJ). TCJ is used with the thermocouple voltage reading to calculate the hot junction temperature (THJ) using the Seedbeck effect.
    3. Select the Units at which to monitor the temperature.
    4. Select the Thermocouple type.
      Table 12. Common Thermocouple Types
      Type Materials Approximate Temperature Range Characteristics
      B Platinum-rhodium (30%)/platinum-rhodium (6%) 0 ℃ to 1700 ℃ Good for high temperatures, stable, expensive.
      E Nickel-chromium/constantan -200 ℃ to 900 ℃ High output, good for low temperatures.
      J Iron/constantan -40 ℃ to 750 ℃ Low cost, limited range due to iron oxidation.
      K Nickel-chromium/nickel-aluminum -200 ℃ to 1260 ℃ Most common, general purpose.
      N Nicrosil/nisil -200 ℃ to 1300 ℃ Stable at high temperatures, better than K in harsh environments.
      R Platinum/platinum-rhodium (13%) 0 ℃ to 1600 ℃ Very stable, used in labs and high-temperature processes.
      S Platinum/platinum-rhodium (10%) 0 ℃ to 1600 ℃ Similar to R, used in industry and labs.
      T Copper/constantan -200 ℃ to 350 ℃ Accurate at low temps, good for cryogenics.
    5. Select the Minimum value for the expected temperature range of the input signal.
    6. Select the Maximum value for the expected temperature range of the input signal.
  6. Click Run.
If the temperature is outside of the defined limits, a warning occurs. However, the Battery Cell Quality Toolkit still provides the results of the test.
After running the VI, view the following results for EIS tests for ACIR tests:
  • Measured frequency (Hz)—The frequency transmitted by the SMU. This value should be within 0.01 Hz from the request frequency of 1000 Hz.
  • Impedance (Ohm). The toolkit calculates the impedance from the following values:
    • Z (Ohm)—The modulus of the impedance.
    • R (Ohm)—The resistance.
    • X (Ohm)—The reactance.
    • Theta (degrees)—The phase between the voltage and the current. Voltage is assumed to be at a zero angle.

View the following additional results for EIS tests:

  • Cole-Cole plot—The impedance values at different frequencies.
  • Magnitude graph—The impedance (Ohms) for different frequencies (Hz).
  • Phase graph—The phase angle for difference frequencies (Hz).