MIL-STD-461G - Volta · 2017-11-10 · •MIL-STD-461G A.4.3.11 – Calibration of measuring...

MIL-STD-461G

I cambiamenti

e la filosofia

Alessandro Corniani

[email protected]

• Preparata da Tri-Service Working Group (TSWG): rappresentanti di US Air Force, Army, Navy e consulenti del settore industriale

• Dal 1993, MIL-STD-461 viene riveduta ogni 5 anni

• MIL-STD-461G è stata emessa in data 11.12.2015

MIL-STD-461G

• MIL-STD-461D e -462D, emesse nel 1993, hanno rivoluzionato le filosofie di prova MIL

• MIL-STD-462D, in particolare, include un check prima delle prove, rimasto unico di queste norme

• MIL-STD-461E, nel 1999, ha combinato le due norme e reso obsoleta MIL-STD-462D

MIL-STD-461E

• Il TSWG considera che un «measurement system integrity check» in tempo reale del set-up prima della prova sia il modo migliore per assicurare una misura corretta

• Per questo motivo, perde importanza la taratura di molti componenti delle prove EMI

• Nota: «measurement system integrity check» rimpiazza «calibration», termine considerato inadeguato

Integrity check

• MIL-STD-461G 4.3.11 – Calibration of measuring equipment – Primary measurement devices and

accessories required for measurement in accordance with this standard shall be calibrated in accordance with ISO/IEC 17025 or ISO 10012 or under an approved calibration program traceable to the National Institute for Standards and Technology.

Integrity check

• MIL-STD-461G 4.3.11 – Calibration of measuring equipment – After the initial calibration, passive

devices such as measurement antennas, current probes, and LISNs, require no further formal calibration unless the device is repaired. The measurement integrity check in the procedures is sufficient to determine acceptability of passive devices.

Integrity check

• MIL-STD-461G A.4.3.11 – Calibration of measuring equipment – In revision G of this standard,

measurement system verification was added to assure that passive devices, such as LISN, current probes, etc. are checked as part of the test. Therefore, periodic calibration is not specified for these devices. In the event the measurement system integrity check does not meet the specific results, use AIR6236.

Integrity check

• In-House Verification of EMI Test Equipment • AIR6236A, emessa in data 01.08.2016 • Check performance of :

– Current probe – Line Impedance Stabilization Network (LISN) – Directional coupler – Attenuator – Cable loss – Low noise preamplifier – Rod antenna base – Passive antennas

SAE AIR6236

http://standards.sae.org/air6236a/



• MIL-STD-461G 4.3.11.2 – Antenna Factors – Factors for test antennas shall be determined

in accordance with SAE ARP958

• MIL-STD-461G A.4.3.11.2 – Antenna Factors – [...] Although the factors produce standardized

results, the true value of the electric field is not necessarily being provided through the use of the factor. Different measuring sensors need to be used when the true electric field must be known.

Antenna factors

• La norma cerca un compromesso tra la correttezza tecnica e ciò che si può fare in una sala prove attrezzata

– Dal 1967, MIL-STD-462 prevedeva 1m di cavi di potenza per CE/CS per ridurre gli errori e 2m per RE/RS

– Per evitare che non fosse così, dal 1993 si prevede da 2m a 2.5m per tutte le prove

– Ecco perché CE102 copre fino a 10MHz invece di 50MHz come prevedeva CE03

Ricerca della ripetibilità

• MIL-STD-461G 4.3.8.2 – Bonding of EUT

– [...] Bonding of the EUT to the ground plane shall be verified in accordance with the installation drawings or equipment specifications before connecting cables and EMI testing. The verification process and results shall be recorded in the EMITR.


• MIL-STD-461G A.4.3.8.2 – Bonding of EUT – [...] verification should be performed prior to

testing to ensure test repeatability and representation of actual installation requirements.

– [...] from bonding points identified in EUT documentation to the ground plane using a mOhm meter to the nearest 10th of a mOhm. The test report should indentify test locations and measurement obtained.

– [...] MIL-STD-464 provides default requirements.


• MIL-STD-461G 4.3.6 – Power source impedance

– [...] LISN shall be electrically bonded to the test ground plane or facility ground as required and the bond resistance shall not exceed 2.5 mOhm.


• MIL-STD-461G 4.3.6 – Power source impedance – [...] LISN impedance plots shall be

provided in the EMITR. – If a LISN impedance needs to be verified, it

is measured under the following conditions: • The impedance shall be measured between the

power output lead on the load side of the LISN and the metal enclosure of the LISN.

• The signal output port of the LISN shall be terminated in 50 Ohm.

• The power input terminal on the power source side of the LISN shall be unterminated.


• MIL-STD-461G 4.3.7.2 – Excess personnel and equipment – The test area shall be kept free of

unnecessary personnel, equpiment, cable racks, and desks.

– [...] All equipment and ancillary gear including antennas that are not being actively used for a particular subset of radiated tests shall be removed from the test area or shielded enclosure.


• MIL-STD-461G 4.3.8.6.1 – Interconnecting cables

– [...] All cables shall be supported 5 cm above the ground plane with non-conductive material such as wood or foam.

Supporto dei cavi

• MIL-STD-461G definisce in maniera più precisa alcuni punti che in passato potevano essere interpretati in maniera non adeguata

• Questa filosofia ha iniziato a prendere piede già dalla versione MIL-STD-461F

Lawyers vs. Engineers

• Già la MIL-STD-461F proibiva l’utilizzo di cavi schermati durante la prova a meno di non avere l’identica applicazione reale per evitare abusi

• La regola è di utilizzare durante la prova la stessa configurazione reale


• MIL-STD-461E 4.3.8.6

– [...] Shielded cables or shielded leads (including power leads and wire grounds) within cables shall be used only if they have been specified in installation requirements.


• MIL-STD-461F 4.3.8.6

– [...] Shielded cables or shielded leads (including power leads and wire grounds) within cables shall be used only if they have been specified in installation requirements. Input (primary) power leads, returns, and wire grounds shall not be shielded.


• La tecnica di pre-taratura dell’intensità di campo con antenna sopra 1GHz è stata rimossa

• Diventa obbligatorio un sensore di campo elettrico su tutta la gamma di frequenze


• Nel 1993 non tutti i laboratori EMI possedevano un sensore di campo da 1..18GHz

• A seguito di un controllo informale presso i laboratorio EMI in US, il 100% delle facilities possiede gli strumenti necessari nel campo da 10kHz a 18GHz


• MIL-STD-461F – 5.17.1 RE102 – [...] The requirement does not apply at

the transmitter fundamental frequencies and the necessary occupied bandwidth of the signal.

• MIL-STD-461G – 5.18.1 RE102 – [...] this requirement does not apply at

the transmitter fundamental frequency and the necessary occupied bandwidth of the signal.


• MIL-STD-461F • 5.13.3.3.c(3) [CS114]

• 5.14.3.3.c(3) [CS115]

• 5.15.3.3.c(3) [CS116]

– Locate the monitor probe 5 cm from the connector. If the overall length of the connector and backshell exceeds 5 cm, position the monitor probe as close to the connector’s backshell as possible

Monitor a 5cm

• MIL-STD-461G • 5.13.3.3.c(3) [CS114]

• 5.14.3.3.c(3) [CS115]

• 5.15.3.3.c(3) [CS116]

– Locate the monitor probe 5 cm from the connector. If the overall length of the connector and backsheel exceeds 5 cm, position the monitor probe as close to the connector’s backshell or backshell’s extension as possible

Monitor a 5cm

• MIL-STD-461D 5.3.9.1.d

– 200MHz to 400MHz optional for all (required only if specified in the procurement specification)

Monitor a 5cm

• Il controllo della corrente deve essere fatto a distanza inferiore a un decimo della lunghezza d’onda

– 𝑑 = 𝜆10 =

𝑐

𝑓10 =

3∙108

10∙𝑓𝑚

– 𝑑400𝑀𝐻𝑧 = 0.075 𝑚 = 7.5 𝑐𝑚

– 𝑑200𝑀𝐻𝑧 = 0.150 𝑚 = 15[𝑐𝑚]

– Lo spettro di CS115 e CS116 è anche inferiore a quello di CS114

Monitor a 5cm

• MIL-STD-461F 1.2.2 – Tailoring of requirements – [...] The test procedures contained in this

document should be adapted by the testing activity for each application. [...]

• MIL-STD-461G 1.2.2 – Tailoring of requirements – [...] The test procedures contained in this

document are generic test methods and should be adapted as necessary for each application, while maintaining the intent of the test, and should be approved by the procuring activity. [...]

Major changes

• MIL-STD-461G A.4.2.2 – Filtering (Navy only)

– Aggiunta di rationale extra per evitare fraintendimenti più o meno volontari (Lawyers vs. Engineers)

Major changes

• MIL-STD-461F 4.3.5.1 – Metallic ground plane – Fig.2

Major changes – Set-up

• MIL-STD-461G 4.3.5.1 – Metallic ground plane – Fig.2


• Dalla Fig.2 alla Fig.4, l’EUT è orientato così da avere l’uscita cavi dal lato corto del tavolo mentre prima veniva posto con l’uscita cavi dal lato lungo del tavolo


• La Fig. 5 che fa riferimento al setup di prova per free standing EUT è cambiata

– Sono aumentate le distanze ai limiti del piano di massa da 1.5m a 2.5m

– Viene tolto il veicolo per mettere un EUT più realistico... visto anche che la norma MIL-STD-461 si applica a equipments e subsystems, non a vehicles!


• MIL-STD-461G 4.3.8.6.1 – Interconnecting leads and cables

• MIL-STD-461G 4.3.8.6.2 – Input (primary) power leads

• Chiarimenti sulla disposizione dei cavi con floor standing unit con estensione verticale

• Anche se la lunghezza dei cavi è maggiore di 2.5 m, l’esposizione sarà di 2 m appoggiata su materiale non conduttivo di altezza 5 cm

Major changes - Cavi

• MIL-STD-461G 4.3.10 – Use of measurement equipment

– [...] Measurement receivers using Fast Fourier Transform (FFT) time domain measurements are acceptable for use, as long as Table II parameters are directly user accessible and can be verified.

Major changes - FFT

Major changes - FFT

• MIL-STD-461G Table II 1/

– Alternative scanning technique. Multiple faster sweeps with the use of a maximum hold function may be used if the total scanning time is equal to or greater than the Minimum Measurement Time defined above [in tabella].

Major changes - FFT

• MIL-STD-461G Table II 2/ – FFT Receivers. FFT measurement technique

may be used provided that FFT operation is in accordance with ANSI C63.2. The user interface of the measurement receiver must allow for the direct input of the parameters in Table II for both FFT Time Domain and Frequency Stepped modes of measurement in the same manner, without the necessity or opportunity to control FFT functions directly.

Major changes - FFT

• MIL-STD-461G A.4.3.10 spiega l’utilizzo dei ricevitori FFT

• I tempi di lettura devono essere adeguatamente stabiliti per evitare di perdere un segnale intermittente in banda larga

• La capacità del ricevitore FFT di catturare bande larghe multiple in pochi secondi permette sicuramente di ottenere dati più precisi

Major changes - FFT

• MIL-STD-461G 4.3.11 – Calibration of measuring equipment – [...] After the initial calibration passive

devices such as measurement antennas, current probes, and LISNs, require no further formal calibration unless the device is repaired. The measurement system integrity check in the procedures is sufficient to determine acceptability of passive devices.

Major changes - Calibration

• MIL-STD-461G 5.5.3.4.a.2 – CE102 procedures – Apply a signal level of 90 dBμV at 10.5 kHz and 100 kHz

to the power output terminal of the LISN. At 10.5 kHz and 100 kHz, use an oscilloscope, in high impedance mode, to verify that there is a proper signal level at the LISN and verify that it is sinusoidal. After establishing the proper signal at the LISN, disconnect LISN and measure resulting voltage using an oscilloscope with 50 ohm input impedance. The ratio of the LISN voltage to the 50 ohm voltage measurement must be within the following tolerances: at 10.5 kHz = -14 dB (+1 dB/-2 dB) and at 100 kHz = -3 dB (+1 dB/-2 dB).

– A seguito dell’eliminazione della necessità di tarature, si richiede un migliore controllo dell’impedenza della LISN a basse frequenze

Major changes – CE102

• MIL-STD-461F 5.6.1 – CE106 applicability – [...] RE103 may be used as an alternative for

CE106 for testing transmitters with their operational antennas.

• MIL-STD-461G 5.6.1 – CE106 applicability – [...] RE103 may be used as an alternative for

CE106 for testing transmitters with their operational antennas. RE102 is applicable for emissions from antennas in receive and standby modes for equipment designed with antennas permanently mounted to the EUT.


• MIL-STD-461G 5.6.1 – CE106 applicability

– [...] For Navy shipboard applications with peak transmitter power greater than 1 kW, the 5% frequency exclusion will be increased by an additional 0.1% of the fundamental frequency for each dB above 1 kW of peak power.

– 𝐼𝑛𝑐𝑟𝑒𝑎𝑠𝑒 =0.001

[𝑑𝐵]𝑃𝑡𝑃𝑘 𝑑𝐵𝑚 − 60 𝑑𝐵𝑚


• MIL-STD-461F 5.6.1 – CE106 applicability – [...] The end frequency of the test is 40 GHz or

twenty times the highest generated or received frequency within the EUT, whichever is less.

• MIL-STD-461G 5.6.1 – CE106 applicability – [...] The equipment will be tested to an upper

frequency limit based on the highest frequency generated or received by the EUT. For systems with the frequencies generated or received less than 1 GHz, the upper frequency limit will be 20 times the highest frequency or 18 GHz whichever is greater. For systems with frequencies generated or received greater than or equal to 1 GHz, the upper frequency limit will be 10 times the highest frequency or 40 GHz whichever is less.


• MIL-STD-461G 5.6.2 – CE106 limits – [...] For Navy shipboard applications,

the second and third harmonics will be suppressed to a level of -20 dBm and all other harmonics and spurious emissions shall be suppressed to -40 dBm, except if the duty cycle of the emissions are less than 0.2%, then the limit may be relaxed to 0 dBm [Radar systems].

• Medesime indicazioni per RE103


• MIL-STD-461F 5.7.1 – CS101 applicability – [...] This requirement is applicable to equipment

and subsystem AC, limited to current draws ≤ 100 amperes per phase, and DC input power leads, not including returns.

• MIL-STD-461G 5.7.1 – CS101 applicability – [...] This requirement is applicable from 30 Hz to

150 kHz for equipment and subsystem AC, limited to current draws ≤ 30 amperes per phase, and DC input power leads, not including returns. This is also applicable to systems that draw more than 30 amps if the system has an operating frequency 150 kHz or less and an operating sensitivity of 1 μV or better (such as 0.5 μV).

Major changes – CS101

• MIL-STD-461G 5.7.3 – CS101 test procedure – [...] There are two methods provided for

making measurements of the applied signal. The first uses an oscilloscope with a power input isolation transformer. The second uses a measurement receiver together with a transducer. The transducer electrically isolates the receiver from the EUT power and reduces the levels to protect the receiver.


• Il power line ripple detector (PRD) misura il ripple indotto su una linea AC, viene inserito tra power line e ingresso a 50 Ohm dell’analizzatore di spettro o del ricevitore e permette di verificare il ripple nel dominio delle frequenze, separata quindi dalla frequenza della power line.


• MIL-STD-461F 5.11 – CS106, conducted susceptibility, transients, power leads

• CS106 verificava la suscettibilità tra cavi di segnale e cavi di potenza e imponeva una segregazione tra i due

• CS115 simula l’accoppiamento di transienti da power bus su cavi di segnale adiacenti

• Le misure hanno verificato che l’impulso da CS115 è più rigido di quello di CS106

• MIL-STD-461G ha quindi eliminato la prova definita in CS106


• MIL-STD-461F 5.12.2 – CS114 limit – [...] Requirements are also met if the EUT is not

susceptible at forward power levels sensed by the directional coupler that are below those determined during calibration provided that the actual current induced in the cable under test is 6 dB or greater than the calibration limit.

• MIL-STD-461G 5.12.2 – CS114 limit – [...] Requirements are also met if the EUT is not

susceptible at forward power levels sensed by the directional coupler that are below those determined during calibration provided that the actual current induced in the cable under test is Curve 5 = 115 dBμA, Curve 4 = 103 dBμA, Curve 3 = 95 dBμA, Curve 2 = 89 dBμA and Curve 1 = 83 dBμA across the frequency range.


• MIL-STD-461G 5.12.3.4.d.2.a – CS114 test procedures – [...] Set the signal generator to 10 kHz

with 1 kHz pulse modulation, 50% duty cycle. Verify that the modulation is present on the drive signal for each signal generator/modulation source combination. Ensure that the modulation frequency, waveform and depth (40 dB minimum from peak to baseline) are correct.


• CS117 – Lightning induced transient susceptibility – Riprende DO-160G Section 22

• CS118 – Electrostatic discharge – Riprende DO-160G Section 25

– Riprende IEC EN 61000-4-2

• Si è discusso ma senza includere la Section 23 – Lightning direct effects che ricade in MIL-STD-810

Nuovi requirements

• MIL-STD-461F 5.17.1 – RE102 applicability – [...] Testing is required up to 1 GHz or 10

times the highest intentionally generated frequency within the EUT, whichever is greater. Measurements beyond 18 GHz are not required.

• MIL-STD-461G 5.18.1 – RE102 applicability – Tutti i requirements chiedono 18 GHz.

Major changes – RE102

• MIL-STD-461F 5.17.3.4.c.3 – RE102 procedures – [...] For the 104 cm rod antenna, remove the rod

element and apply the signal to the antenna matching network through a 10 pF capacitor connected to the rod mount as shown in Figure RE102-8.

• MIL-STD-461G 5.18.3.4.c.3 – RE102 procedures – [...] For the 104 cm rod antenna, remove the rod

element and apply the signal to the antenna matching network through a capacitor connected to the rod mount as shown on Figure RE102-8. The capacitor value is nominally 10 pF, but shall be per the manufacturer’s instruction.

Major changes – RE102

Requirement Equipment type

General Time domain EMI receiver

CS101 Frequency domain ripple monitoring tranducer

CS114 Current probe calibration fixture

CS117 Indirect lighting test system

CS118 ESD gun

RS103 1..18 GHz electric field probe

New equipment

Un sentito grazie a

Ken Javor

per l’ispirazione.

MIL-STD-461G - Volta · 2017-11-10 · •MIL-STD-461G A.4.3.11 – Calibration of measuring...

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