G.R.A.S. 45CA Instruction Manual Download

Page: 22 / 31

Analyzer with hardware and software

for simulating:



a signal generator capable of

generating the requred test signals



an audio frequency analyser ca-

pable of ⅓-octave band analyses

To headphones

To analyzer

Headphone amplifier

Headphones under test

Power Module

Type 12AK

From Ear Simu-

lator RA0039

Test Fixture Type 45CA

G.R.A.S.

Power Module

Type 12AK

Gain

+20

+10

+30

+40

+50

Dir

Lin

Filter

Overload

Inst.

Latch

SysCh.

Adjust

Power

Ovl.

Reset

Low

Batt.

Signature Series

Output

Input

080014

G.R.A.S.

ISO 4869-3 Hearing-protector Test Fixture

Type 45CA

Serial No. XXXXX

080001

G.R.A.S. SOUND & VIBRATION

Page 22

Hearing-Protector Test Fixture Type 45CA

5.5

Typical Application Setup

Fig. 5.17 shows a block diagram of an application setup for testing headphones.

Fig. 5.17 Block diagram of a set-up for testing a pair of headphones

Summary of Contents for 45CA

Page 1: ...Instruction Manual Hearing Protector Test Fixture Type 45CA Skovlytoften 33 2840 Holte Denmark www gras dk gras gras dk SOUND VIBRATION G R A S ...

Page 2: ...Revision 28 November 2013 LI0024 ...

Page 3: ...4 4 5 Typical Application Setup 15 5 Configuration with IEC 60318 Ear Simulator RA0039 16 5 1 Ear Simulator Preamplifier Assembly 16 5 2 Calibration 17 5 3 Completing the Assembly 18 5 4 Mounting Assembly into Test Fixture 19 5 5 Typical Application Setup 22 6 Configuration with IEC 60711 Ear Simulator RA0045 or RA0045 S1 23 6 1 Assembling Ear Simulator and Preamplifier 23 6 2 Mounting the Assembl...

Page 4: ...C 60318 4 Ear Simulator RA0045 IEC 60318 IEC 60318 1 Ear Simulator RA0039 1 1 Main Features The Test Fixture Type 45CA provides for reliable and exact measurements and was designed with the following features The test fixture mounted on a resilient base Fig 1 1 that reduces the noise floor to a mini mum in a typical test situation Foam plugs and grease Fig 1 1 are supplied to avoid sound leakage a...

Page 5: ...be configured with a microphone externally polarized or prepolarized IEC 60711 Configuration with Ear Simulator RA0045 These ear simulators are for use with a pinna simulator artifical ear for measuring the sound pressure at the eardrum DRP thus also applicable for ear inserts RA0045 available both in externally polarized or prepolarized versions Standard ISO 4869 3 IEC 60318 IEC 60711 Test Setup ...

Page 6: ...ient base GR0986 1 x Test fixture neck Allen keys 1 x 6 0 mm YY0019 1 x 2 5 mm YY0016 1 x 2 0 mm YY0018 1 x 1 5 mm YY0012 2 Delivered Components 2 x Cover plate GR1085 1 x Test fixture head 1 x Allen screw 6 mm SK1544 Fig 2 1 Parts delivered in the Type 45CA box 2 x Insert GR0970 Tube of Sealing Grease MI0016 2 x Foam Plug GR1281 ...

Page 7: ...se 3 After making sure both of the 1 5 mm Allen grub screws in the head s steel tube are loosened to their extreme positions place the head onto the pedestal and carefully slide the steel tube onto the top of the pedestal s neck Fig 3 3 4 Tighten both of the 1 5 mm Allen grub screws on the steel tube Fig 3 4 IMPORTANT Tighten both of these 1 5 mm Allen grub screws Fig 3 3 Fig 3 4 Test fixture head...

Page 8: ...Microphone 1 Type 40EN or Type 40AP 40AD Applications Insertion Loss of Ear Muffs If Microphone 1 Type 40EN is used the configuration is in conform ity with ISO 4869 3 Required Accessories The parts shown in Fig 4 1 choose one of the three assembly options Pistonphone Type 42AP recommended or Type 42AA Test instruments such as those shown in Fig 4 14 4 1 Assembling Microphone and Preamplifier Fig ...

Page 9: ...h optional 1 coupler adapter For instructions on calibrating the microphone preamplifier assembly refer to the piston phone s instruction manual The Pistonphone Type 42AP is delivered with an adapter for calibrating 1 microphones Fig 4 2 Assembly of 1 microphone and preamplifier to be calibrated G R A S SOUND VIBRATION Page 9 Hearing Protector Test Fixture Type 45CA ...

Page 10: ...ted at delivery G R A S SOUND VIBRATION Page 10 Hearing Protector Test Fixture Type 45CA Fig 4 3 Cover plate and insert to be mounted 2 Using Allen key 1 5 mm loosen the two 1 5 mm grub screws Fig 4 3 and separate the head from the pedestal Up Insert GR0970 Allen grub screws 1 5 mm Right Cover plate GR1085 Screws 2 0 mm Hole for screw 1 5 mm ...

Page 11: ...neck slide the cable into the inner slot hole of the rubber pad on top Fig 4 7 Fig 4 6 Fig 4 7 6 Push the two Foam Plugs GR1281 into the cable guide right underneath the rubber pad one plug on top of the other while keeping the cable behind the plugs Fig 4 8 7 If required for meeting your requirements for acoustic isolation apply Grease MI0016 to seal leakage points Fig 4 9 Fig 4 8 Fig 4 9 2 x Foa...

Page 12: ...the pedestal Fig 4 10 Note Do not forget to tighten both of the 1 5 mm Allen grub screws To Power module Head Microphone preamplifier assembly Pedestal Tube Split hole Slides on and off the pedestal Fig 4 10 Cabeling for the microphone preamplifier assembly Always tighten both of the 1 5 mm screws ...

Page 13: ...microphone s diaphragm must be level in the vertical plane with the slanting surface of the head For Microphone Type 40EN this will be the case when the center of the protection grids sticks out by 1 89 mm in the vertical plane with the slanting surface of the head Use the grub screws to pinch the microphones lightly to hold them in position Note If you cannot get the microphone positioned to the ...

Page 14: ... facing the microphone into the recess surrounding the microphone until it makes contact with the base of the recess Fig 4 13 4 Fig 4 14 On the opposite side of the Type 45CA push Plug GR1079 into the hole as far as it will go For sound leakage sealing apply Silicon Grease MI0016 to the plug 5 Type 45CA is now ready to be tested for acoustic isolation Fig 4 15 Fig 4 12 Fig 4 13 Fig 4 14 Fig 4 15 A...

Page 15: ...or simulating a signal generator capable of gen erating the required test signals an audio frequency analyser capa ble of octave band analyses Loudspeaker To analyzer Power amplifier Ear muffs under test Power Module Type 12AK From preamplifier Test Fixture Type 45CA G R A S Power Module Type 12AK Gain 20 10 30 40 50 0 HP Dir Lin AW Filter Overload Inst Latch SysCh Adjust Power On Ovl Reset Low Ba...

Page 16: ...ting ear inserts earphones and earplugs Required Accessories The items of one of the two assembly options shown in Fig 5 1 Pistonphone Type 42AP recommended or Type 42AA Test equipment such as the instruments shown in Fig 5 15 5 1 Ear Simulator Preamplifier Assembly Fig 5 1 displays the two options for configuration with Ear Simulator RA0039 Note Do not assemble the parts yet proceed to Section 5 ...

Page 17: ... on calibrating the microphone preamplifier assembly Fig 5 3 see the Pistonphone Type 42AP or Type 42AA instruction manual Fig 5 3 microphone and preamplifier to be calibrated to Adapter GR0010 included with the preamplifiers Externally Polarized Microphone Type 40AG CCP Preamplifier Type 26CB Prepolarized Microphone Type 40AO Fig 5 2 Assembling the parts required for the calibration Cable AA0018 ...

Page 18: ...ig 5 4 2 Place the adapter RA0176 Fig 5 5 3 Remount the microphone Fig 5 6 4 Screw Ear Simulator RA0039 onto the assembly Fig 5 7 Complete assembly NB Threaded side must face upwards G R A S SOUND VIBRATION Page 18 Hearing Protector Test Fixture Type 45CA ...

Page 19: ...t Cover Plate GR1085 already mounted at delivery Remove Insert GR0970 Fig 5 8 Test fixture Type 45CA prepared for the RA0039 assembly Up Recess for screw 1 5 mm Cover plate GR1085 Insert GR0970 Right Screws 2 0 mm 2 Using Allen key 1 5 mm loosen the grub screw Fig 5 8 and separate the head from the pedestal Allen grub screws 1 5 mm ...

Page 20: ...ck slide the cable into the inner slot hole of the rubber pad on top Fig 5 12 Fig 5 11 Fig 5 12 6 Push the two Foam Plugs GR1281 into the cable guide right underneath the rubber pad one plug on top of the other while keeping the cable behind the plugs Fig 5 13 7 If required for meeting your requirements for acoustic isolation apply Grease MI0016 to seal leakage points Fig 5 14 Fig 5 13 Fig 5 14 2 ...

Page 21: ...Pedestal Tube Fig 5 15 8 Replace the head onto the pedestal Fig 5 15 Note Do not forget to tighten the two 1 5 mm Allen grub screws Fig 5 16 9 Insert the RA0039 assembly firmly into the recess Fig 5 16 RA0039 assembly Grub screw for holding the microphone in position Use Allen key 2 5 mm YY0016 Tighten both of the 1 5 mm screws ...

Page 22: ...ype 45CA G R A S Power Module Type 12AK Gain 20 10 30 40 50 0 HP Dir Lin AW Filter Overload Inst Latch SysCh Adjust Power On Ovl Reset Low Batt Signature Series Output Input 080014 G R A S ISO 4869 3 Hearing protector Test Fixture Type 45CA Serial No XXXXX 080001 G R A S SOUND VIBRATION Page 22 Hearing Protector Test Fixture Type 45CA 5 5 Typical Application Setup Fig 5 17 shows a block diagram of...

Page 23: ...eamplifier Type 26CB for monaural measurements only Type 26CS CCP preamplifier allowing binaural measurements Applications Hearing protection devices ear muffs earplugs Sound sources headphones supra aural circum aural earphones Required Accessories The parts shown in one of the three assembly options Fig 6 1 KEMAR Pinna Simulator artificial ear one of the types listed in section 6 4 Pinna Holder ...

Page 24: ...test fixture 1 Remove Cover Plate GR1085 and Insert GR0970 Fig 6 2 Fig 6 2 Test fixture Type 45CA cover plate and insert removed Hole for 1 5 mm screw Cover plate GR1085 Insert GR0970 2 Replace the 1 5 mm screw in base of recess Fig 6 3 The socket headcap screw is used as locator for the pinna Fig 6 3 Allen grub screws 1 5 mm Recesses for 2 0 mm screws 1 5 mm screw ...

Page 25: ...neck slide the cable into the inner slot hole of the rubber pad on top Fig 6 7 Fig 6 6 Fig 6 7 6 Push the two Foam Plugs GR1281 into the cable guide right underneath the rubber pad one plug on top of the other while keeping the cable behind the plugs Fig 6 8 7 If required for meeting your requirements for acoustic isolation apply Grease MI0016 to seal leakage points Fig 6 9 Fig 6 8 Fig 6 9 2 x Foa...

Page 26: ...head onto the pedestal Note Do not forget to tighten the two 1 5 mm screws Fig 6 10 To Power module Head Microphone preamplifier assembly Pedestal Tube Press until inner edge is flush with recess surface Grub screw for lightly pinching and holding the coupler in position Use Allen key 2 5 mm YY0016 Fig 6 11 Always tighten both of the 1 5 mm screws ...

Page 27: ...pter RA0157 must be ordered separately LED Display 2 Mount the Calibration Adapter RA0157 into the pistonphone 1 Loosen the pistonphone s retention collar 3 a Switch on the pistonphone via the I O button b Check that the LED is showing green c Place the pistonphone Type 42AP shown carefully onto the ear canal Note Hold the pistonphone strictly horizontally Fig 6 12 Fig 6 13 Fig 6 14 G R A S SOUND ...

Page 28: ...ng sure that it locates with the screw in the recess push the pinna into the recess so that it makes full contact with the base of the recess Fig 6 15 2 Make sure the pinna edge is flush with the test fixture surface all the way around Mount the Cover Plate RA0172 must be ordered separately using the four 2 0 mm screws supplied with it This cover plate will keep the pinna in place Fig 6 16 Fig 6 1...

Page 29: ...re and software for simulating a signal generator capable of gen erating the required test signals an audio frequency analyser capa ble of octave band analyses Loudspeaker To analyser Power amplifier Earplug under test Power Module Type 12AK From Ear Simu lator RA0045 Test Fixture Type 45CA G R A S Power Module Type 12AK Gain 20 10 30 40 50 0 HP Dir Lin AW Filter Overload Inst Latch SysCh Adjust P...

Page 30: ...Built in accordance with ISO 4869 3 can also be used with two microphones for binaural testing Weight 11 6kg Dimensions in millimeters and inches 53 00 mm 394 00 mm 155 60 mm G R A S ISO 4869 3 Hearing protector Test Fixture Type 45CA Serial No XXXXX 200 00 mm 135 00 mm 5 32 15 51 2 09 7 87 6 13 Ø Ø Ø ...

Page 31: ... configuration For reasons of space the short preamplifiers are required for binaural measurements that is Type 26AS for externally polarized configurations Type 26CS for prepolarized configurations For monaural measurements you can also use Type 26AC for externally polarized configuration Type 26CB for prepolarized configuration The 26AS and 26AC used for the externaly polarized con figurations h...

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