ETSI TR 100 028

Uncertainty Calculation

The report outlines the mathematical methods for identifying and combining individual sources of measurement error, such as cable attenuation, antenna alignment, and instrument tolerances. Under ETSI TR 100 028, these individual uncertainty components are combined using the root-sum-square method to produce an expanded uncertainty value. This expanded value represents the overall margin of error for the entire test setup at a specified confidence level, allowing labs to document their test accuracy and prove their competence during formal audits.

Laboratory Compliance

Accreditation bodies evaluate testing laboratories against the procedures in this report to confirm that their measurement systems are within acceptable error limits. It provides the reference guidelines for calculating the safety margins applied during product compliance testing. This prevents disputes over test results between manufacturers and regulatory agencies.

Technical Guidance

The document contains practical examples of uncertainty budgets for common wireless tests, including transmitter output power and receiver adjacent channel selectivity. By following these examples, laboratory engineers can design test setups that minimize measurement errors. This systematic approach improves the repeatability of test results and the reliability of certified wireless products.