part 2 traceability kjell bergh[1]
Post on 21-Jul-2016
229 Views
Preview:
TRANSCRIPT
June 2004 slide 1
Part 2 Calibration
Kjell Bergh
June 2004 slide 2
Content
External vs. in-house calibrationCalibration vs. validation vs. verificationPassive devices
Cables, attenuators, directive couplers, LISN etcActive devices
Preamplifiers, Power amplifiers, Pulse limitersComplex instruments
Receivers, ESD simulators, EFT/B generators, Surge generatorsSystems
Absorbing clamp, Van Veen loop, RF immunity systems, Emission systems
June 2004 slide 3
External vs. in-house calibration
ExternalPreferably accredited calibration laboratoriesManufacturer calibration of specific equipmentOther calibration labs, as long as they maintain traceability
In-houseDepends on own organizationSimple passive devicesRF immunity set-up calibrationNSAChamber field homogeneity
June 2004 slide 4
Calibration vs. validation vs. verification
Priorities to considerEnsure “true” value in measurementAt “all” timesEnsure traceabilityMaintain confidence in labCompetence of personnel
Sequence of eventsCalibration at long intervals (1-3 Yrs)Validation at short intervals (monthly)Verification before each test
June 2004 slide 5
Definitions
CalibrationPeriodic assessment of a piece of equipment or system against a number of defined parameters. Usually performed by an external calibration laboratory, the measurements are traceable to SI standards.
ValidationAn assesment of a piece of test equipment or system against the requirements of the test standard.
An initial validation is performed at the end of test development Regular validations are performed to demonstrate ongoing compliance to the test standard
VerificationA quick and simple measurement or test to ensure that a piece ofequipment or system is functioning correctly
June 2004 slide 6
Calibration
Applied to single instruments, one at a time
Define critical instrumentation parametersCertificate of deviations from nominal valuesCertificate with uncertainty valuesTraceable to SI standards via secondary standardsAccredited
June 2004 slide 7
Validation
Tertiary standard (traceable)Most critical parametersTrend recordApproximation to exact valuesComparison to “fresh” calibrationMay be system oriented
June 2004 slide 8
Trend analysis
Parameter
Time
June 2004 slide 9
Verification
Verify proper functionSingle parameterEasy to testFailure indicates major problemMaximum coverage of instruments
June 2004 slide 10
External calibration
Define important parameters to be calibratedAccreditation scope of cal.lab.If not, may we still rely on the unaccredited calibration?”Pass/fail” verdict or numeric deviations from nominalCombine deviations and calibration uncertainty into equipment uncertaintyTransportationHandling timeRepair and/or adjustments
June 2004 slide 11
Calibration uncertainty
Assume:a) Max. deviation from nominal reading, rectangular distribution
k=√3: δXb) Cal. uncertainty, normal distribution
k=2: Ucal
Then measurement uncertainty:
22 )3
()2
( XUu calreading
δ+=
June 2004 slide 12
Hierarchy of calibration standards
A calibration standard is a unit that specifies a physical parameter
International standardNational standardPrimary standardSecondary standardTertiary standardEtc.
June 2004 slide 13
In-House calibration
Passive devicesCablesAttenuatorsDirectional couplersTransducers like LISN, CDN, ISN, current clamps, antennas
Reference standards (tertiary standards traceable by external accredited calibration):
Receiver with tracking generator
Directional couplerReceiver + generatorNetwork analyzer calibration kitPower meterField probe
Gen Rec.DUC
Reflection measurementRec.
June 2004 slide 14
2bPassive devices
May in many cases be calibrated in-house
June 2004 slide 15
Critical parametersPassive devices
Cables and attenuatorsInsertion lossImpedance all ports (If NA is used)Stability to mechanical stressMatch both ends
Directional couplersInsertion loss all combinations of two portsImpedance all ports (If NA is used)Mechanical stabilityMatch all ports (Through ports most important)
Network analyzer orReceiver with
tracking generator
June 2004 slide 16
Critical parametersPassive devices
LISN (Calibrated externally)EuT port impedance, 9 kHz to 30 MHz.EuT port to RF port insertion loss (may be validated in-house)Line to neutral isolation RF port impedanceAE port isolationAvailability of cal. jig?
LISNEuT port
AE port
RF port
June 2004 slide 17
Critical parametersPassive devices
CDN (Validated only)EuT port to RF port insertion lossAE port to RF port isolationRF port impedance
CDN
RF port
EuT port AE port
June 2004 slide 18
Critical parametersPassive devices
Current clamp (monitor clamp) (External calibration)Conversion factor (Frequency response) Insertion impedance on line under testRF port impedance match
EMF
Iline
June 2004 slide 19
Critical parametersPassive devices
ISN (for telecom ports) (External calibration)
Insertion lossLCLEuT port impedance (common mode to ground)AE port to RF port isolation (alternatively AE to EuT port)RF port impedancePolarity reversal?
ISN
RF port
EuT port AE port
June 2004 slide 20
Critical parametersPassive devices
Antennas (used in emission tests) (External calibration)
AF at sufficiently dense frequency stepsImpedance matchCross-polarization (if applicable)Balance (if applicable)Polar diagram, E- and H-plane, at least to 45° fromboresightCalibration at another OATS than where it is to be used
June 2004 slide 21
Critical parametersPassive devices
High-voltage probe (External calibration)Conversion factorRF port impedance match
1500Ω
June 2004 slide 22
2cSimple active instruments
June 2004 slide 23
Critical parametersActive devices
Pulse limiter (for conducted test) (External calibration)
Insertion lossPulse limiting capability (Verification)Impedance match in- and out-port
10 dB attenuation
June 2004 slide 24
Critical parametersActive devices
Preamplifiers (used in emission tests) (may be calibrated in-house using tertiary standards)
Gain over frequency bandImpedance match, in- and out-port
PreamplifierGain
MatchFreq. span
June 2004 slide 25
Critical parametersActive devices
Power amplifier (Validation)Gain accross bandSmallest max output power levelHarmonic content at 3 dB back-off from max levelImpedance match in- and out-portPower stability with temperatureOverload behaviour
Pout
Psat-3 dB
-8 dB
Pin
June 2004 slide 26
Critical parametersActive devices
Power meter (External calibration)Reading acccuracy with sinewave in (calibrated)Sensitivity stability (time, temperature)Input impedance matchIn-house validation
Meter response to 80% AM rel CW, same generator settingassuming power amplifier in linear mode.
PAM
PCW
PIN,CW
June 2004 slide 27
2dComplex instruments
June 2004 slide 28
Critical parametersComplex instruments
Receivers (for radiated test) (External calibration)Sine-wave response at low levels (+0 to +30 dB relative noise floor)Pulse amplitude response, PK, QP and AV detectorsPRF response for QP detectorInput impedance match with:
Preamplifier on, no input attenuationPreamplifier off, no input attenuationPreamplifier off, 10 dB input attenuation
Noise floor under conditions aboveIF bandwidths as applicableFrequency stability (e.g. that it is OK)
June 2004 slide 29
Receivers
Sinewave response
1 10 100 1000 Hz
QP response to PRF
6 dB bandwidth
Freq.step
N0
Signal
June 2004 slide 30
Critical parametersComplex instruments
Receivers (for conducted test) (External calibration)Sine-wave response at low levels (+50 to +80 dB relative noise floor)Pulse amplitude response, PK, QP and AV detectorsPRF response for QP detectorInput impedance match with:
Preamplifier off, no input attenuationPreamplifier off, 10 to 50 dB input attenuation
Noise floor under conditions aboveIF bandwidths as applicableFrequency stability (e.g. that it is OK)
June 2004 slide 31
Critical parametersComplex instruments
Signal generator (Validation)Output sinewave levels resettability (validation)Modulation index at 80% (calibrated)Effect on RMS power level when modulation is switched ONSinewave purityOutput impedance matchFrequency stability (e.g. that it is OK)Software control stability
June 2004 slide 32
Critical parametersComplex instruments
ESD generator (gun) (External calibration)
Current into 2 ΩAt peakAt 30 nsAt 60 ns
Risetime into 2 ΩLevels:
+ 1, 2, 4, 8 kV- 1, 2, 4, 8 kV
June 2004 slide 33
Critical parametersComplex instruments
EFT/Burst generator (External calibration)
Pulse peak, rise time and 50% timePulse PRF 85 kHz, 2,5 kHz)Burst duration Burst intervalTest durationSettings:
Line - LineLines - Ground+/- polarity
June 2004 slide 34
Critical parametersComplex instruments
Surge generator (Combination wave) (External calibration)
2 Ω source, 12 Ω source, 42 Ω sourceLine – LineLines – Earth1, 2, 4 kVPulse risetime and 50% time, open and short-circuitPulse synchronization with mains phase, 0°, 45°,90°, etc.
June 2004 slide 35
2eSystems
In most cases, the system is validated in-house, but components has external calibration
June 2004 slide 36
Emission
June 2004 slide 37
SystemsCalibration colour semantics
External calibration
In-house calibration
Compensated in set-up
No calibration
EuTPartial calibration
June 2004 slide 38
Critical parametersSystems
Radiated emissionComponents
AntennaAntenna mast w/controlsCables(Preamplifier)ReceiverTurntableSite (OATS or semianechoic room) with ground planeRef. source
June 2004 slide 39
In-House calibrationNSA calibration
Preferably other antennas than normal test antennaBoth antennas calibrated recently (tertiary standard)Receiver/tracking generator recently calibrated (tertiary standard)Appropriate softwareCalibrated cables (fourth-level standard)
Gen. Rec.
June 2004 slide 40
SystemsRadiated emission
EuT
Rec
PreampEN 55022 Sec. 6
Ant
June 2004 slide 41
Critical parametersSystems
Emitted powerComponents
Absorbing clamp (external calibration)Clamp rangePower cableRF cableReceiver (external calibration)(Shielded chamber)Clamp pulling deviceCalibration and verification jigs/targets etc. (external calibration)Supply filters and added absorbers
June 2004 slide 42
SystemsDisturbance power
EuT Clamp
Rec.
EN 55014-1sec. 4.1.2
June 2004 slide 43
Critical parametersSystems
Absorbing clamp (for emitted power) (External calibration)
Conversion factor (Frequency response)Calibration certificateIn-house with small target (ref. measurement on OATS)In-house with jig
RF port impedance matchAE port isolation
June 2004 slide 44
Absorbing clamp calibration
Receiver/generator
Reference plane 2x2 m External calibration
June 2004 slide 45
Absorbing clamp validationIn-House calibration (may also be externalfor comparison)
Receiver/generator
10 dB
Target
June 2004 slide 46
Validation jig
In-House validation at intervals
Receiver/generator
June 2004 slide 47
Critical parametersSystems
Mains conducted emissionComponents
LISNGround planeEuT table / palletReceiverPulse limiterCables
June 2004 slide 48
SystemsConducted emission
EuT
2.LISN
40 cm
Rec
(L)ISN
80 cm
EN 55022 sec. 5
June 2004 slide 49
Critical parametersSystems
Discontinuous disturbanceComponents
LISNGround planeEuT table / palletClick AnalyzerPulse limiterCables
June 2004 slide 50
SystemsClick-noise disturbance
EuT
40 cm
LISN
80 cm
Click-noise
analyzer
EN 55014-1 sec. 4.2
June 2004 slide 51
Critical parametersSystems
Telecom port emissionComponents
ISNCurrent probe, as applicableVoltage probe, as applicableFerrite attenuator, as applicableLISN for power supplyGround planeEuT table / palletReceiverCables
June 2004 slide 52
Telecom port emission
EuT
2.LISN
40 cm
Rec
ISN
80 cm
EN 55022 sec. 9
June 2004 slide 53
Non-invasive measurements
EuT CP Fe-absorber AE
150Ω
Receiverdual
Current probe
EuT CP Fe-absorber AECVP
Voltage probe
Alt. 1
Alt. 2
June 2004 slide 54
Critical parametersSystems
Luminarie insertion lossComponents
LISN, 150 ΩBalunDouble 75 Ω coaxReceiver with tracking generatorDummy tubes, for applicable luminarieCables
June 2004 slide 55
SystemsLuminary insertion loss
EN 55015 sec. 4.2
Luminary
RX/TXcombo
LISNBalun
Pair of 75Ω coax
June 2004 slide 56
Critical parametersSystems
Luminary H-field emissionComponents
Large loop antenna (Van Veen) – Radiated H-fieldReceiverCablesLoop switch controlCalibration probe (inspection for integrity)
June 2004 slide 57
SystemsRadiated H-field emission
Receiver
EN 55015 sec. 4.4
In-house calibration toavoid transportationand include ambient
June 2004 slide 58
Critical parametersSystems
Van Veen loop
June 2004 slide 59
Critical parametersSystems
Harmonics and flicker analyzer (Internal calibration with calibrator. Calibrator calibrated externally)
Power sourceContinous current capability and purityInrush current capabilitySource impedanceVoltage and frequency setting accuracy
AnalyzerCurrent reading 0 – 2000 HzLeast significant reading (mA), each harmonicDmax, Dc, Pst and Plt evaluationSoftware operation, Fluctuating vs. steady harmonicsComparison with limits
June 2004 slide 60
SystemsHarmonics and flicker
EN 61000-3-2EN 61000-3-3
EuT
Powersupply
Analyzer
Impedancenetwork
Harmonics/Flicker
Calibrator
June 2004 slide 61
Flicker characteristics
ZREF = 0,4 + j0,25 ΩRA = 0,25 Ω, XA = j0,15 ΩRN = 0,15 Ω, XN = j0,1 Ω
June 2004 slide 62
Immunity
June 2004 slide 63
SystemsESD immunity test
ESD EuT High-speedoscill.
0,5 mm
HCP
Pellegrinitarget
EN 61000-4-2VCP
June 2004 slide 64
Critical parametersSystems
Radiated RF immunityComponents
GeneratorPower amplifierCablesDirectional couplers(Switches)Antenna(s)Anechoic chamberField probe(s) w/monitorPower meter(s)
Set-up calibration
June 2004 slide 65
In-House calibration
Field homogeneity calibrationCalibrated field probe (tertiary standard)Defined positioning jig for probeDefined antenna positionIf added absorbers, defined positionAppropriate software for job
June 2004 slide 66
SystemsRadiated RF immunity
EN 61000-4-3
EuT
Ant
Gen PA
Pwrm.
Field probemonitor
June 2004 slide 67
SystemsEFT/Burst immunity
EN 61000-4-4
EuT
EFT/Bgenerator
EuT
Cap. clamp
June 2004 slide 68
SystemsSurge immunity
EN 61000-4-5
EuT
Surgegenerator
June 2004 slide 69
Critical parametersSystems
Conducted RF immunityComponents
GeneratorPower amplifierAttenuatorCablesCDNPower meterCalibration jigGround planeCurrent monitor probeMonitor receiver/power meter
Set-up calibration
June 2004 slide 70
In-House calibration
Set-up calibration (immunity) traceabilityCalibrated power meter(s) (tertiary standard)Calibrated field probe (tertiary standard)Directional coupler with sufficient directivityValidated attenuators and cablesVerified CDNsGenerator with calibrated AM(tertiary standard)Table of expected levels
CDN
GEN PA Pwrm.
Set-up calibration
6 dB
June 2004 slide 71
SystemsConducted RF immunity
EN 61000-4-6
CDN
EuT
CDN
GEN PA Pwrm.
Set-up calibration
6 dB
Rec.
6 dB
Testing
10 cm
June 2004 slide 72
Critical parametersSystems
EM clampConversion factorAE port isolationRF port impedance match
Part of set-up calibration, in-house
Receiver/generator
June 2004 slide 73
SystemsPower freq. H-field immunity
EN 61000-4-8
EuT
Power freqCurrentsource
DVM H-fieldmeter
June 2004 slide 74
Critical parametersSystems
Power frequency H-fieldLoop designCurrent generatorCurrent monitorField homogeneity
May be validated in-house
Helmholtz coilSingle loop coil
June 2004 slide 75
SystemsVoltage dips and interruption
EN 61000-4-11
EuT
Simulator
top related