45aa instruction manual · 2020. 10. 25. · 2. on the right-hand side, remove the grub screw, a,...

Instruction Manual

www.gras.dkLI0128– 4 July 2017

G.R.A.S. 45AA Telephone Test Head

Revision History

Any feedback or questions about this document are welcome at [email protected].

Revision Date Description

1 9 July 2008 First release

2 28 September 2015 Removal of end stop added to page 13

3 4 July 2017 42AG substituted for the obsolete 42AB

Copyright Notice

© 2008-17 G.R.A.S. Sound & Vibration A/S

www.gras.dk

Any technical documentation that is made available by G.R.A.S. is the copyrighted work of G.R.A.S. and is owned by G.R.A.S.

The content in this document is subject to change without notice. G.R.A.S. Sound & Vibration A/S is not liable or responsible for any errors or inaccuracies that may appear in this document.

Trademarks

Any product names mentioned in this document may be trademarks or registered trademarks of their respective companies and are hereby acknowledged.

G.R.A.S. Sound & Vibration

CONTENTS

1. General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.1 Positioning of the Mouth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.2 Anti-vibration Mounts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.3 Handset Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.4 Modifiyingthelateralguidestoadjustindependently . . . . . . . . . . . . . . . . . . . . . . . 5

2. Physical Set-ups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.2 Mounting a G.R.A.S. Ear Simulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

IEC 60318 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6IEC 60711 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.3 Mounting a G.R.A.S. Mouth Simulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.4 CheckingSpeakingPositions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.5 ClampingArrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3. Test Set-ups and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.1 TestSetups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.2 Calibration and Calibration Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

CalibrationofanIEC60318Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Calibration Check of an IEC 60711. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215. Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22


Telephone Test Head Type 45AA - Page 4

1. General DescriptionTheG.R.A.S.TelephoneTestHeadType45AA(Fig.1.1)isatailor-madefixturefortestingtheacousticperformanceoftelephonehandsetsinaccordancewithinternationalstandardsandrecommendations.Itsdesigncombinesprecisionwitharobustconstructiontoensurestabilityandreproducibletestresultswithaminimumofacousticinterference.WhenusedwithanArtificialEarType43ADoranEarSimulatorType43AE,andaMouthSimu-latorType44AAor44AB,itcanbesetupfortestingtelephonehandsetsinaccordancewithITU-T recommendations.

1.1 Positioning of the MouthFourdifferent,detachablebracketsareprovidedformountingtheMouthSimulatoraccordingtothestandardisedpositionsshowninTable.1.1forspeakingintoatelephone.Thesepositionsaremaintainedtowithinanaccuracyof1 mm.Referencegauges(RA0141)areavailableforverifyingthis.

Fig. 1.1 Telephone Test Head Type 45AA showing: Left; fitted with a G.R.A.S. Mouth Simulator and IEC 318 Ear Simulator Type 43AD Right; computer rendering outlining its chief components

Speaking Position RecommendationLRGP ITU-T Rec. P76AEN ITU-T Rec. P76HATS ITU-T P58REF OREM A

Table 1.1 Speaking positions according to current recommendations

Independentlyadjust-able lateral guides

GU0138forapply-inganadjustablespring-loadedforce

Adjustablelongitudinalstop.Latermodelswithalockingscrew

Lockingscrew



1.2 Anti-vibration MountsTheType45AAstandsonfouranti-vibrationmountstoisolateitfromextraneousvibrationswhichcouldotherwiseleadtospuriousmeasurementresults.

1.3 Handset AlignmentTheType45AAisprovidedwithgraduatedguidesandstopsforaligningatelephonehandsetcorrectlyinpositionovertheArtificialEar.Lateralguidesareindependentlyadjustabletocaterforbothsymmetricalandasymmetricalhandsets-seesection1.4.Oncealigned,anadjustablespring-loaded,rubberpadwillholdthehandsetinposition(seeFig.1.2).Asspecifiedinsometests,anadjustableforcecanbeappliedbyaddingonlyasmallmasstothemeasurementobject.Alternatively,theclampingarrangementshowninFig.2.11maybeused.

Fig. 1.2 Showing graduated stops and guides for aligning a telephone handset

Fig. 1.3 Close-up of the longitudinal stop



1.4 Modifiyingthelateralguidestoadjustindependently Thelateralguidesarefactory-settoadjustsymmetrically(toaccommodatesymmetrichandsets). Tomodifythelateralguidestoadjustindependently(toaccommodateasymmetrichandsets),removethecouplingkeys(DinFig.1.4),whichcoupleeachpair’sright-handandleft-handshaftstogether.

Procedure1.Adjustthelateralguidestotheirextremepostionswithmaximumdistancebetweenthem.2.Ontheright-handside,removethegrubscrew,A,usingthesuppliedminimum-sizedallenkey.3.Pullouttheshaft,B,andtheshaftcentre-bearing,C.4.Removethecouplingkey,D,locatedintheslotattheendoftheshaft.Ifthecouplingkey stayedinsidetheshafttunnel,tiltthecompletestandslightlyuntilitdropsout. NB!Storethecouplingkeysafely,e.g.intheplasticbagtogetherwiththeallenkeys.5.Remounttheshaft,B,andthecentre-bearing,C.6.Tightenthegrubscrew,A. ( 1 : 2 ) ( 1 : 2 )

A ( 1 : 1 )

A ( 1 : 1 )

A

( 1 : 2 ) ( 1 : 2 )

A ( 1 : 1 )

A ( 1 : 1 )

A

C

C

C

B

B

A

A

B

D

D

D

Fig. 1.4 Removing the coupling key, D.



2. Physical Set-ups

2.1 IntroductionTheTelephoneTestHeadType45AAcanbesetupphysicallytoaccommodatestandardisedmeasurementsusingaccordinglyanyofthefollowing:

G.R.A.S. Ear Simulators• Type43AD(IEC60318)• Type43AE1(IEC60711)

G.R.A.S. Mouth Simulators• Type44AA• Type44ABmountedforanyofthefollowing:

Speaking positions• LRGP• AEN• HATS• REFTwoclampingarrangementsareprovidedforholdingatelephonehandsetinpositiononcethelateralguidesandlongitudinalstop(Figs.1.2and1.3)havebeenadjusted.

2.2 Mounting a G.R.A.S. Ear Simulator

2.2.1 IEC 60318Fig.2.1showsanexplodedviewofhowtomounttheIEC60318EarSimulatorontheTel-ephoneTestHead.

2.2.2 IEC 60711Fig.2.2showsanexplodedviewofhowtomounttheIEC60711EarSimulatorontheTel-ephoneTestHead.

1 Alternatively,acombinationof½-inchPreamplifierType26AK,EarSimulatorRA0045andPinnaSimulatorRA0056(Fig.2.2)

Spring-loadedfloatingpad

ArtificialEarType43ADIEC60318(availablefromG.R.A.S.)

GR0903Scaleandtworetainingscrews

Note:correctloca-tionofthesepins

Threadedsupport-canberotatedfrombelowtoadjustspringforceunderfloatingpad

GR0338 removable ring

GR0402 removable ring

GR0902Scalewithlargeaperturetoaccomodate concave ear pieces

RA0039 2

Seatingforfloatingpad



Fig. 2.1 Exploded view of a set up using an IEC 318 Artificial Ear (available from G.R.A.S.)

2 TheType43ADusesaG.R.A.S.EarSimulatorRA0039.ThiscanbesubstitutedbyaG.R.A.S.EarSimulatorRA0137whichhasabuilt-insoundsourceintheformofasmallloudspeaker.SignalsareappliedtothisloudspeakerviaanSMBconnector.Thisfeatureisfordetectingtheoccurrenceofanychangesinsoundleakage(withrespecttoanexpectedamount)betweentheEarSimulatorand,say,abadly-positionedhandset.

RA0045 housingIEC60711(availablefromG.R.A.S.)

½-inchPreamplifierType26AK(availablefromG.R.A.S.)

RA0056Low-leakPinna(availablefromG.R.A.S.)

GR0903Scaleandtworetainingscrews

GR0902Scalewithlargeaperturetoaccommodate concave ear pieces

Spring-loadedfloatingpad

Note:correctloca-tionofthesepins

Threadedsupport-canberotatedfrombelowtoadjustspringforceunderfloatingpad

Seatingforfloatingpad



Fig. 2.2 Exploded view of a set up using an IEC 711 Ear Simulator (available from G.R.A.S.)

GR0826

GR0829

GR0828 GR0827



2.3 Mounting a G.R.A.S. Mouth SimulatorAMouthSimulatorcanbemountedfourdifferentwaysdependingonwhichspeakingpositionisrequired.TheTelephoneTestHeadisdeliveredwithfourdifferentbrackets,oneforeachspeak-ingposition,seeFig.2.3.Fig.2.4showsanexplodedviewofhowtomounttheMouthSimulatorontheTelephoneTestHead.ItiseasiertostartbyfirstattachingthebracketfortherequiredspeakingpositiontotheMouthSimulatorthenmountingtheassemblyontheTestHead.

Fig. 2.3 Brackets for determining the various standard speaking positions of the Mouth Simulator, i.e. LRGP, AEN, HATS and REF

Fig.2.5showsthestandardspeakingpositionoftheMouthSimulatorforeachofthebracketsshowninFig.2.3.Anoptionalguage(RA0141)isavailablefromG.R.A.S.forcheckingtheAENandREFspeakingpositons.Seesection2.4.

BracketfordeterminingtherequiredspeakingpositionoftheMouthSimulator,i.e.LRGP,AEN,HATSorREF(SeeFig.2.3)

MouthSimulatorType44AA/44AB(availablefromG.R.A.S.)

Mountingpadwithtopandbottomlocatingpins

GR0871:Largethreadscrewsthroughbracket,smallthreadscrewsintoMouth Simulator

Screwsintobracket

Screwsintomountingpad



Fig. 2.4 Exploded view showing details of mounting a Mouth Simulator on the Telephone Test Head. Start by first attaching the bracket to the Mouth Simulator

AEN

REF

HATS

LRGP

GR0828

GR0829

GR0827

GR0826

Mouth Simulator

Mouth Simulator

Mouth Simulator

Mouth Simulator



Fig. 2.5 Showing the standard speaking position of the Mouth Simulator (available from G.R.A.S.) when mounted on each of the brackets shown in Fig. 2.3

Hole for IEC 318 ArtificialEar(minusremovablering)

REF(shortspike)AEN(longspike)

Stub

M5 Unbraco mounting screwforendstop

Endstop



Fig. 2.6a The two components of the guage RA0141 (available from G.R.A.S.) for checking the AEN and REF speaking positions

2.4 Checking Speaking PositionsTheTestHeadisrobustandisphysicallystable.Therefore,checkingthespeakingpositionswouldnotnormallybenecessaryifitistreatedproperly.However,ifthereisreasontobelievethatithasbeendamaged(e.g.fallingoffabench),aspecialgauge(RA00141)isavailablefromG.R.A.S.forcheckingtheAENandREFspeakingpositions,seeFig.2.6.Figs.2.7and2.8showhowthisgaugeshouldbeused.Thespeakingpositioniswherethetipsofthespikeandstubmeet.Theymustmeetwithinatleast1mmdistancebetweenthemtosignifythattheTestHeadisinworkingorder.

Fig. 2.6b The end stop mechanism and its M5 Unbraco mounting screw.

BeforemountingtheRA0141gauge,theendstopmustberemoved.Theendstopanditshous-ingismountedwithanM5boltfromtheundersideasshowninFig.2.6b.

Maximumclearance1mm

Maximumclearance1mm

IEC318ArtificialEar

IEC318ArtificialEar

Placedcentrally

Placedcentrally



Fig. 2.7 The guage RA0141 (available from G.R.A.S.) set up for checking the AEN speaking position (IEC 318 Artificial Ear minus its removable ring). Note: the same speaking position will be indicated by the LRGP bracket which in effect moves the postion of the handset through the angular distances shown in Fig. 2.9. NOTE: The end stop must be removed, see Fig 2.6b.

Fig. 2.8 The guage RA0141 (available from G.R.A.S.) set up for checking the REF speaking position (IEC 318 Artificial Ear minus its removable ring)

Y-axis

AEN

140 mm

Lipring

REF136 mm

15½°

22°

18°

12.9°

39°

13°

X-axis

ERP

Approximateorien-tationofLipring

Z-axispointsawayfrom the reader



Fig. 2.9 Showing where the Lip-ring (of the Type 44AA / 44AB) should be for both AEN and REF positions. The angular distances of 39° and 13° (in that order) will move the handset from the AEN postion to the LRGP

Rubberpadonspring-loadedarm

Adjustandlockheightofspring-loadedpad

Rotatetoadjustspringforceonarm



2.5 Clamping ArrangementsTwodetachableclampingarrangementsareprovided.EachisattachedtotheTestHeadbyapairofscrews.Donotattempttousethenbothclampingarragementsatthesametimesincethepointofcontactwiththetelephonehandsetisthesame.Thetwoclampingarrangementsare:• Spring-loadedClampGU0138(seeFig.2.10)

Fortestingtelephonehandsetsandmobiletelephonesduringtheirdevelpment.• SnapClampGU0133(seeFig.2.11)

Forroutinelytestingbatchesoftelephonehandsetsandmobiletelephones.

Fig. 2.10 Clamping arrangement using the Spring-loaded Clamp GU0138

Screwpositions:Toptwoholes-minimumheightMiddletwoholes-mediumheightBottomtwoholes-maximumheight

Spring-loadedpad

Adjustandlockverti-calpositionofspring-loadedpad

Snaplock

Release



Fig. 2.11 Clamping arrangement using the Snap Clamp GU0133



3. Test Set-ups and Calibration

3.1 Test Set upsUsinganyoneofthephysicalset-upsdescribedinchapter2,theTelephoneTestHeadType45AAcanbeusedfortestingtheperformanceofboththeearandmouthpiecesofacompletehandsetormobiletelephone.Twoexamplesoftestset-upsusingadditionalG.R.A.S.equipment1areshowninFigs.3.1and3.2.Fig.3.1showsablockdiagramofaset-upfortestingacompletetelephonehandset.Thisarrangementisprobablybettersuitedtotestsinconnectionwithdevelopinganewhandsetormobiletelephone.Fig.3.2showsablockdiagramofacomputer-controlledset-upforroutinelytestingcompletetelephonehandsets.Thisarrangementisprobablybettersuitedtotestsinconnectionwithcheckingbatchesofhandsetsormobiletelephones.

1 SeparatedatasheetsareavailableforalltheG.R.A.S.equipmentshownFigs.3.1and3.2

Computerwithhardwareandsoftwareforsimulating: a signal generator capableofgeneratinglogarithmicallyswepttonesequalisedfortheparticularMouth Simulator

anaudiofrequencyana-lysercapableofwidebandmeasurements

Equalisedsweepsignal from generator

Toanalyser

Poweramplifier

To G.R.A.S. Mouth Simulator

Telephoneundertest

PowerModuleType12AK

FromG.R.A.S.EarSimulator

Computerwithhardwareandsoftwareforsimulating: a signal generator capableofgeneratinglogarithmicallyswepttonesequalisedfortheparticularMouth Simulator

anaudiofrequencyana-lysercapableofwidebandmeasurements

Equalised conditioned sweepsignal

Toanalyser

To G.R.A.S. Mouth Simulator

Telephoneundertest

PowerModuleType12AP

FromG.R.A.S.EarSimulator

RS232 control

Fromgenerator



Fig. 3.1 Block diagram of a set-up for testing a complete telephone handset

Fig. 3.2 Block diagram of a computer-controlled set-up for routinely testing complete tel-ephone handsets



3.2 Calibration and Calibration Check

3.2.1 Calibration of an IEC 60318 Set up (see Fig. 2.1)Forthis,accesstothemicrophoneisnecessary.1) TwistopenthetwohalvesofthesnapcouplingasshowninFig.3.3.2) GentlypushthemicrophoneintothePistonphone’scoupleruntilitreachesthestop

(Fig.3.4).3) SwitchthePistonphoneon.4) Settheanalyser(Fig.3.1)toeitherwidebandortothe⅓octavebandwhosecentrefre-

quencyis250Hz.5) Whenconditionsarestable,adjusttheanalysersothatitcorrectlygaugesthePistonphone

signal(nominally114dB).SeePistonphonemanualformakingbarometriccorrections.6) SwitchthePistonphoneoffandremoveitfromthemicrophone.7) Re-assembletheArtificialEar.

3.2.2 Calibration Check of an IEC 60711 Set up (see Fig. 2.2)Important!donotextractthemicrophonehousedintheRA0045Couplersincethiscouldinvali-datethefactorycalibrationoftheCoupler.Ifiteverbecomesnecessarytoextractthemicro-phone,usethespecialtoolRA0071availablefromG.R.A.S.Thefollowingprocedure,usingaG.R.A.S.Pistonphone,shouldpreferablybecarriedoutatthefollowingtimes:

a) beforeafirst-timeuseofanIEC60711EarSimulatortoestablishabaselineforsub-sequent checks

b) thereafteratappropiateintervalstocheckforrepeatabilityThePistonphonemustbefittedwitha1-inchMicrophoneCouplerRA0023andusedwithaspecialAdapterRA0119(availablefromG.R.A.S)fortheIEC60711EarSimulator.1) ThesetupforthecalibrationcheckisshownFig.3.5(showingasetupforaG.R.A.S.IEC

60711EarSimulatorType43AE).2) MakesurethattherubbersealofthePinnaSimulatorseatsfirmlyinsidetheAdapter.3) SwitchthePistonphoneon.4) SettheGainontheType12AK(Fig.3.1)to0.5) Settheanalyser(Fig.3.1)toeitherwidebandortothe⅓octavebandwhosecentrefre-

quencyis250Hz.6) Whenconditionsarestable,notethereadinginmillivolts.

Foramicrophoneofnominalsensitivity(12.5mV/Pa)andanominalPistonphonesignalof114dB,anapproximatevaluefortheLow-leakPinnaSimulatorRA0056is:• 95mV(representingadropof≈2.4dB)

7) Repeat,ifrequired,withtheHigh-leakPinnaSimulatorRA0057fitted,acorrespondingapproximatevalueis:• 15mV(representingadropof≈18.4dB)

RA00231-inchCoupler

RA0119PistonphoneAdapter

Low-leakPinnaSimulator RA0056

IEC 60318

IEC 60318

IEC 60711



Fig. 3.5 Calibration-check set-up. Make sure that the rubber seal of the Pinna Simulator seats firmly inside the Pistonphone Adapter

Fig. 3.3 Showing the two halves of the snap coupling to give quick access to the microphone

Fig. 3.4 Gently push the microphone into the Pistonphone’s cou-pler until it reaches the stop



4. SpecificationsMouth positions:

Speaking Position RecommendationLRGP ITU-T Rec. P76AEN ITU-T Rec. P76HATS ITU-T P58REF OREM A

Accuracy:directionofmouthaxis:- ±1mmplainofmouth:- ±2mm

Handset alignment:Fourlateralguidesindependentlyadjustableover35mmtocaterforasymmetricalhandsets.Longitudinalstopadjustableover35mm.Alladjustmentsrelativetocentreofcoupleraperture.Twotypesofadjustablepaddedclampsareprovided.

Dimensions:Height: 375mm(14.8in)Width: 180mm(7.1in)Depth: 200mm(7.9in)Weight: 2.3kg(5.6lb)

Accessories included:Detachablebracketsforspeakingpositions LRGP: GR0826 AEN: GR0827 HATS: GR0828 REF: GR0829Adjustabledetachableclamps Springloaded: GU0138 Snap: GU0133



5. AccessoriesMouth Simulators withamplifier Type44AA withoutamplifier Type44AB

IEC60318ArtificialEar Type43ADIEC60711EarSimulator Type43AELow-leakPinnaSimulator RA0056(incl.inType43AE)High-leakPinnaSimulator RA0057(incl.inType43AE)

Pistonphones: Type42AA Type42APCalibrator: Type42AG

PowerModules Type12AK,Type12AQ

Reference Gauges RA0141

45aa instruction manual · 2020. 10. 25. · 2. on the right-hand side, remove the grub screw, a,...

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