45aa instruction manual · 2020. 10. 25. · 2. on the right-hand side, remove the grub screw, a,...
TRANSCRIPT
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Instruction Manual
www.gras.dkLI0128– 4 July 2017
G.R.A.S. 45AA Telephone Test Head
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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.
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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
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G.R.A.S. Sound & Vibration
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
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Independentlyadjust-able lateral guides
GU0138forapply-inganadjustablespring-loadedforce
Adjustablelongitudinalstop.Latermodelswithalockingscrew
Lockingscrew
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 5
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
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G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 6
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.
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G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 7
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)
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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
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 8
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.
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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
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 9
Fig. 2.2 Exploded view of a set up using an IEC 711 Ear Simulator (available from G.R.A.S.)
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GR0826
GR0829
GR0828 GR0827
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 10
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.
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BracketfordeterminingtherequiredspeakingpositionoftheMouthSimulator,i.e.LRGP,AEN,HATSorREF(SeeFig.2.3)
MouthSimulatorType44AA/44AB(availablefromG.R.A.S.)
Mountingpadwithtopandbottomlocatingpins
GR0871:Largethreadscrewsthroughbracket,smallthreadscrewsintoMouth Simulator
Screwsintobracket
Screwsintomountingpad
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 11
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
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AEN
REF
HATS
LRGP
GR0828
GR0829
GR0827
GR0826
Mouth Simulator
Mouth Simulator
Mouth Simulator
Mouth Simulator
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 12
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
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Hole for IEC 318 ArtificialEar(minusremovablering)
REF(shortspike)AEN(longspike)
Stub
M5 Unbraco mounting screwforendstop
Endstop
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 13
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.
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Maximumclearance1mm
Maximumclearance1mm
IEC318ArtificialEar
IEC318ArtificialEar
Placedcentrally
Placedcentrally
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 14
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)
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Y-axis
AEN
140 mm
Lipring
REF136 mm
15½°
22°
18°
12.9°
39°
13°
X-axis
ERP
Approximateorien-tationofLipring
Z-axispointsawayfrom the reader
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 15
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
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Rubberpadonspring-loadedarm
Adjustandlockheightofspring-loadedpad
Rotatetoadjustspringforceonarm
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 16
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
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Screwpositions:Toptwoholes-minimumheightMiddletwoholes-mediumheightBottomtwoholes-maximumheight
Spring-loadedpad
Adjustandlockverti-calpositionofspring-loadedpad
Snaplock
Release
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 17
Fig. 2.11 Clamping arrangement using the Snap Clamp GU0133
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G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 18
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
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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
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 19
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
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G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 20
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)
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RA00231-inchCoupler
RA0119PistonphoneAdapter
Low-leakPinnaSimulator RA0056
IEC 60318
IEC 60318
IEC 60711
G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 21
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
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G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 22
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
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G.R.A.S. Sound & Vibration
Telephone Test Head Type 45AA - Page 23
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