THEMIS INSTRUMENT PER 1 UCB, May, 2005

EMC / Mag Instrument Test Plan & ResultsMichael Ludlam

University of California - Berkeley

THEMIS INSTRUMENT PER 2 UCB, May, 2005

EMC Test Results

Instrument suite EMC test was performed at EMCE in Fremont, CA on FM1, April 05. Only Conducted Emissions and Conducted Susceptibility measurements were made.

Subsequent EMC testing (on FM2-6) will be done at bench level at UCB.

Results detailed in THM_SYS_REP_003_EMC.doc

(contains completed procedure THM_SYS_PROC_003_EMC.doc)

EMC levels for E have been calculated and documented in “THEMIS Environmental Design Specification SAI-SPEC-1148 Revision – A”. H field levels are located in the magnetic test plan (reference on page 7 of these slides). These levels have been fixed since early 2004.

THEMIS INSTRUMENT PER 3 UCB, May, 2005

EMC Testing

THEMIS INSTRUMENT PER 4 UCB, May, 2005

Instrument Compatibility

Grounding

Instrument suite verified to meet grounding scheme prior to EMC testing.

Voltage Ripple

From ETU testing, Instruments have set limit on probe power bus of 100mV p-p noise (EFI constraint).

Instrument Functionality

No instrument to instrument noise issues.

THEMIS INSTRUMENT PER 5 UCB, May, 2005

Conducted Emission Results

CE01 Conducted Emissions 30Hz – 15kHz

Emissions slightly above specification at top end of test, however only by 0.8dB.

CE03 Conducted Emissions 15kHz – 50MHz

Background measurement taken is above the specification – therefore need to look at the difference between ‘background’ and ‘instrument on’. Slight difference in 1-9 MHz noise from EFI motors.

CE07 Voltage Transients

Passed

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CE01

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CE03

Instrument On.

Motors On

Ambient

Instrument On.

Motors Off

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Conducted Susceptibility Results

CS01 Conducted Susceptibility 30Hz – 50kHz • Noise seen on EFI & SST, but no criteria failed. Passed.

CS02 Conducted Susceptibility 50kHz – 400MHz• Passed.

CS07 Conducted Susceptibility spikes

•Passed.

THEMIS INSTRUMENT PER 9 UCB, May, 2005

Mag Test PlanDC Fields•Detailed Magnetics Control Plan (ftp://apollo.ssl.berkeley.edu/pub/THEMIS/1 Management/1.3 Systems Engineering/1. Requirements/thm_sys_002d_Magnetic Cleanliness.pdf)•Early problem component identification and testing (EFI Motors and SST Sensors).•Modelling of instrument fields.•Magnetic mapping of all units before installation onto probes•Deperming of tools for flight model assembly and integration

AC Fields•Careful implementation of Magnetics Control Plan recommendations e.g. twisting of power and return lines in harnesses.•Currently there are no instrument AC fields issues•SCM Team made measurements in clean room and at EMC of different instrument configurations.•Final check during S/C EMC test.

THEMIS INSTRUMENT PER 10 UCB, May, 2005

Magnetic Coil Facility

Used for instrument mapping and deperming