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Automotive OEM Requirement for EMC Test Method Measurement Uncertainty

3. April 2023 11:01 by Christian in EMC/EMI, EMC TEST PLAN, Uncertainty
Automotive EMC/Electrical testing specs like GM3097:2019, GMW3172:2022, FMC1278:2021, FMC1279:2021,

Automotive EMC/Electrical testing specs like GM3097:2019, GMW3172:2022, FMC1278:2021, FMC1279:2021, CS0054:2018,
VW80000:2021 do not mention Measurement Uncertainty as requirement for reports.

CISPR 25:2021 includes INFORMATIVE Measurement Uncertainty but this is not a requirement for CISPR 25 compliant reports.

4.1.5 Test report
The report shall contain the information agreed upon by the customer and the supplier, e.g.
• sample identification,
• date and time of test,
• bandwidth,
• step size,
• required test limit,
• ambient data and test data.
Annex L (informative) Measurement instrumentation uncertainty – Emissions from components/modules – Test methods.
Annex M (informative) Uncertainty budgets for emissions from components/modules.

ISO 7637-2:2021 - no reference to Measurement Uncertainty.
ISO 7637-3:2016 - no reference to Measurement Uncertainty.
ISO 16750-2:2012 - no reference to Measurement Uncertainty.
ISO 16750-1:2018 - no reference to Measurement Uncertainty.


ISO 11452-2:2019 - no reference to Measurement Uncertainty.
ISO 11452-4:2020 - no reference to Measurement Uncertainty.
ISO 11452-8:2015 - no reference to Measurement Uncertainty.
ISO 11452-9:2012 - no reference to Measurement Uncertainty.
1SO 10605:2008 - no reference to Measurement Uncertainty.

Measurement Uncertainty is not a requirement for automotive electronic standards, nor a requirement of the vehicle OEMs. Measurement
Uncertainty is already included in the test levels (e.g. RE Limit Lines or RI Severity Level) for the automotive standards. These the limits are not affected by the measurement uncertainty budget generated by the laboratory for each test.

In the Commercial Electronics world (FCC & CE Mark), the Measurement Uncertainty is included in the report. This is because these
Commercial Standards require that a certain measurement uncertainty be achieved in order to apply the specified limits. If the lab's
measurement uncertainty doesn't meet the minimum requirements, then the limits must be adjusted based upon the lab's measurement
uncertainty calculations. However, this is not the case in the Automotive Industry.

Christian Rosu (Apr 2, 2023)