ISO EMI Compatibility Standards – UPN 297 GRC Project Manager – Dawn Emerson

1. ISO EMI Compatibility Standards – UPN 297GRC Project Manager – Dawn Emerson Prepared by Noel B. Sargent Analex Corporation -- GRC

2. Project Description • Provide technical expertise and lead the development of space system standards in the area of EMI/EMC. Represent NASA on various EMC focused committees and working groups involved in the development and coordination of standards that affect military, government, and the international aerospace community.

3. Project Goal • As a government representative and member of EMC focused committees, aid in the development, preparation and approval of EMC space systems standards. Ensure that the interests of NASA are reflected in the development of new standards. Provide technical expertise, experience, and knowledge to identify test methods and procedures leading to achieving unified approaches acceptable to the national and international EMC space systems community.

4. Brief History • 1994 -- Initial ISO task to lead and develop ISO 14302, Systems electromagnetic compatibility requirements. • 2000 – NWIP from Germany to develop test methods standard • 2002 – ISO 14302 First Edition approved • 2003 – US urged to lead development of NWI on test reporting requirements.

5. NWIP Current Status • Scope of NWIP agreed at WG1 meeting in Oct 2003 • Anticipated presentation of NWIP outline at May 2004 Plenary Meeting – deferred • Continue work on initial draft for presentation at upcoming WG1 Oct 2004 • Coordinated initial draft with national experts, and discussed go-forward plan with ESA representative

6. NWIP – Electromagnetic Interference (EMI) Test Reporting Requirements for Space System Equipment • Recommend cancellation of DIS 23037 “EMI test methods for space equipment”. Retain the measurement categories, but change the focus of the document to test reporting requirements from that of detailed test method configurations and procedures. • NWIP would standardize test report content, but not graphical presentation format. Coordinate with WG2 N270, WD19933 • NWIP would require test plan augmentation, and specific reporting, in cases when the equipment under test does not meet the test limit. • NWI will contain a rationale appendix to describe the need for such test augmentation to aid understanding of how the data will be applied to systems analysis.

7. Test Reporting Example • Assume a scientific instrument, or critical monitor requires an accuracy of 3%. The equipment under test (EUT) must meet a radiated susceptibility requirement of 20 volts per meter below 1 GHz. • Normal test procedures require determination of “degradation of performance” when the test limit cannot be met. Is degradation of performance a just-noticeable difference in EUT response, or when the EUT exceeds the 3% accuracy requirement? And what is the response of the EUT at full test level? What are the reporting requirements? • If the EUT does not meet the test requirement, and the EUT is expected to be used (waiver) without correction of this deficiency, at least three levels of susceptibility need to be determined and recorded. • The test level at noticeable degradation of performance • The test level at the EUT operational specification requirement • The response of the EUT at full test level

8. Adjunct Standards Activities • Participate in annual DOD E3 review • MIL-STD-1541(B) re-write in process • MIL-STD-461(F) re-write in process • Participate in annual IEEE EMC Society meeting and present status of ISO work to the Standards Advisory and Coordination Committee (SACCom) • Participate in annual European EMC Symposium and space systems panels

9. Closing Thoughts • ISO EMC standardization efforts must focus on unification of (continuing) differences in global EMI qualification philosophies (FCC, European Norms, MIL, RTCA) to ensure that those differences do not result in incongruence of shared data. • Program managers must (through top-level directives) involve EMI personnel at the outset (definition phase) of programs.