Summary of Contents for G.R.A.S. 45CA
- Page 1 G R A S SOUND & VIBRATION Skovlytoften 33, 2840 Holte, Denmark www.gras.dk gras@gras.dk...
- Page 2 Revision 28 November 2013 LI0024...
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Page 3: Table Of Contents
CONTENTS Introduction ........... . . 4 Main Features . -
Page 4: Introduction
• IEC 60711 (IEC 60318-4) Ear Simulator RA0045. • IEC 60318 (IEC 60318-1) Ear Simulator RA0039. 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 along the cable. -
Page 5: Which Configuration To Use
Hearing-Protector Test Fixture Type 45CA 1.2 Which Configuration to Use Table 1 shows what each of the three configurations can be used for: ISO 4869-3 Configuration with 1" (or ½" *) Microphone * Pressure microphones, both externally and polarized types available. The configuration is applicable for testing outside-the-ear devices; i.e. • For measuring the insertion loss of ear muffs • For testing the sound quality of earphones IEC 60318 Configuration with Ear Simulator RA0039 RA0039 simulates an ear and is used for measuring the sound pressure at the ear entrance point (EEP). -
Page 6: Delivered Components
Tube of Sealing Grease MI0016 1 x Acoustic plug 1 x Test GR1079 1 x Allen screw 6 mm fixture neck 2 x Foam Plug SK1544 GR1281 Fig. 2.1 Parts delivered in the Type 45CA box. Page 6 G.R.A.S. SOUND & VIBRATION... -
Page 7: Important! Basic Assembly - Safety Instructions
Hearing-Protector Test Fixture Type 45CA IMPORTANT! Basic Assembly - Safety instructions Before proceeding to one of the three configuration options in sections 4, 5, or 6, do the basic assembly of the test fixture according to step 1-4: 1. Place the test fixture neck onto a solid table, and find the supplied screw and 6 mm Allen key (Fig. 3.1). 2. Place the screw into the bottom of the resilient base, and screw the base onto the neck with the Allen key (Fig. 3.2). -
Page 8: Configuration With Pressure Microphone, 1" Type 40En Or ½" Type 40Ap/40Ad
Hearing-Protector Test Fixture Type 45CA Configuration with Pressure Microphone, 1" Type 40EN or ½" 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... -
Page 9: Calibration
Hearing-Protector Test Fixture Type 45CA Calibration Before mounting the microphone/preamplifier assembly into the test fixture, you must calibrate the assembly using Pistonphone Type 42AP or Type 42AA (with 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. -
Page 10: Mounting The Assembly Into The Test Fixture
Hearing-Protector Test Fixture Type 45CA 4.3 Mounting the Assembly into the Test Fixture 1. See Fig. 4.3: – Mount the Cover Plate GR1085. – Mount the Insert GR0970. (Both items are already mounted at delivery). Insert GR0970 Screws, Allen grub screws, 1.5 mm 2.0 mm Right Cover plate GR1085 Fig. - Page 11 Hearing-Protector Test Fixture Type 45CA 3. Pass the amplifier’s LEMO plug end through the side of the head (fig. 4.4) until it drops through the tube (Fig. 4.5). Fig. 4.4 Fig. 4.5 4. Pull the cable through until there is just a manageable amount sticking out of the side of the head (Fig. 4.6). 5. On top of the neck, slide the cable into the inner slot hole of the rubber pad on top (Fig. 4.7).
- Page 12 Hearing-Protector Test Fixture Type 45CA 8. Replace the head onto the pedestal (Fig. 4.10) Note: Do not forget to tighten both of the 1.5 mm Allen grub screws. Head Tube Microphone/preamplifier assembly Split hole Slides on and off the pedestal...
- Page 13 Hearing-Protector Test Fixture Type 45CA 9. The last step is to ensure correct microphone positioning: Figure 4. of ISO 4869-3 shows that the center of the 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.
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Page 14: Acoustic Isolation Testing
Fig. 4.12 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). -
Page 15: Typical Application Setup
Hearing-Protector Test Fixture Type 45CA Typical Application Setup Fig. 4.16 shows a block diagram of an application setup for testing the insertion loss of a pair of ear-protection muffs. Ear muffs under test G.R.A.S. ISO 4869-3 Hearing-protector Test Fixture Type 45CA G.R.A.S. -
Page 16: Configuration With Iec 60318 Ear Simulator Ra0039
Hearing-Protector Test Fixture Type 45CA Configuration with IEC 60318 Ear Simulator RA0039 This ear simulator can be used with • ½" Externally Polarized Pressure Microphone Type 40AG • ½" Prepolarized Pressure Microphone Type 40AO. Applications Monaural or binaural measurements of • Hearing protection devices: Ear muffs (supra-aural, circum-aural) • Sound sources: Headphones (supra-aural, circum-aural). Note: As the coupler is not for use with a pinna simulator, it cannot be used for testing ear-inserts (earphones and earplugs). -
Page 17: Calibration
Hearing-Protector Test Fixture Type 45CA Calibration To calibrate this configuration, use Pistonphone Type 42AP or Type 42AA. Both of them are delivered with an adapter for calibrating ½″ microphones. 1. Assemble the parts shown in Fig. 5.2 Externally Polarized Microphone Prepolarized Microphone ″ ½ Externally ″ ½ Prepolarized Polarized Microphone Microphone Type 40AO Type 40AG ″ ½ to ¼″ Adapter GR0010 (included with the ¼″ preamplifiers) ¼″ CCP ¼″ Preamplifier... -
Page 18: Completing The Assembly
Hearing-Protector Test Fixture Type 45CA 5.3 Completing the Assembly 1. Unscrew the microphone 3. Remount the microphone Fig. 5.6 Fig. 5.4 2. Place the adapter RA0176. 4. Screw Ear Simulator RA0039 onto the assembly NB! Threaded side must face upwards. Fig. 5.5 Fig. 5.7 Complete assembly Page 18 G.R.A.S. -
Page 19: Mounting Assembly Into Test Fixture
Hearing-Protector Test Fixture Type 45CA Mounting Assembly into Test Fixture 1. See Fig. 5.8: • Mount Cover Plate GR1085 (already mounted at delivery). • Remove Insert GR0970. Insert GR0970 Allen grub screws, Screws, 1.5 mm 2.0 mm Right Cover plate GR1085 Fig. 5.8 Test-fixture Type 45CA prepared for the RA0039 assembly 2. Using Allen key 1.5 mm, loosen the grub screw (Fig. 5.8), and separate the head from the pedestal. - Page 20 Hearing-Protector Test Fixture Type 45CA 3. Pass the amplifier’s LEMO plug end through the side of the head (fig. 5.9) until it drops through the tube (Fig. 5.10). Fig. 5.9 Fig. 5.10 4. Pull the cable through until there is just a manageable amount sticking out of the side of the head (Fig. 5.11). 5. On top of the neck, slide the cable into the inner slot hole of the rubber pad on top (Fig.
- Page 21 Hearing-Protector Test Fixture Type 45CA 8. Replace the head onto the pedestal (Fig. 5.15) Note: Do not forget to tighten the two 1.5 mm Allen grub screws. Head Tube Microphone/preamplifier assembly Pedestal Tighten both of the 1.5-mm screws To Power module Fig.
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Page 22: Typical Application Setup
Hearing-Protector Test Fixture Type 45CA Typical Application Setup Fig. 5.17 shows a block diagram of an application setup for testing headphones. Headphones under test G.R.A.S. Power Module Type 12AK Power Batt. SysCh. Ovl. Adjust Reset Overload Inst. Latch Gain G.R.A.S. -
Page 23: Configuration With Iec 60711 Ear Simulator Ra0045 Or Ra0045-S1
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 Kit for Type 45CA (RA0172) - see section 6.4 • For Calibration: – Pistonphone Type 42AP (recommended) or Type 42AA – Calibration Adapter RA0157 (must be ordered separately) • Test instruments such as those shown in Fig. -
Page 24: Mounting The Assembly Into The Test Fixture
Hearing-Protector Test Fixture Type 45CA 6.2 Mounting the Assembly into the Test Fixture Next step is to mount the assembly into the test fixture. 1. Remove Cover Plate GR1085 and Insert GR0970 (Fig. 6.2). Insert GR0970 Recesses for 2.0-mm screws Allen grub screws, 1.5 mm Cover plate GR1085 Fig. 6.2 Test-fixture Type 45CA, cover plate and insert removed 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. - Page 25 Hearing-Protector Test Fixture Type 45CA 3. Pass the amplifier’s LEMO plug end through the side of the head (Fig. 6.4) until it drops through the tube (Fig. 6.5). Fig. 6.4 Fig. 6.5 4. Pull the cable through until there is just a manageable amount sticking out of the side of the head (Fig. 6.6). 5. On top of the neck, slide the cable into the inner slot hole of the rubber pad on top (Fig. 6.7).
- Page 26 Hearing-Protector Test Fixture Type 45CA 8. Replace the head onto the pedestal, Note: Do not forget to tighten the two 1.5-mm screws (Fig. 6.10) Head Microphone/preamplifier Tube assembly Pedestal Always tighten both of the 1.5-mm screws To Power module Fig. 6.10 9. Insert the RA0045 assembly into the test fixture.
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Page 27: Calibrating Iec 60711 Ear Simulator Coupler Ra0045
Hearing-Protector Test Fixture Type 45CA Calibrating IEC 60711 Ear Simulator Coupler RA0045 Note: Requires a Calibration Adapter RA0157 (must be ordered separately). 1. Loosen the pistonphone’s retention 3. a. Switch on the pistonphone via the I/O button. collar. b. Check that the LED is showing green. -
Page 28: Mounting The Kemar Pinna
Hearing-Protector Test Fixture Type 45CA 6.4 Mounting the KEMAR Pinna The following KEMAR pinnae are available for use with the Type 45CA. Large Pinna right KB0070 Large Pinna left KB0071 Small Pinna right KB0072 Small Pinna left KB0073 All have the same hardness, i.e. Shore 00-55 RA0172 –... -
Page 29: Typical Application Setup
Hearing-Protector Test Fixture Type 45CA Typical Application Setup Fig. 6.16 shows a block diagram of an application setup for testing the insertion loss of an ear- plug. Earplug under test G.R.A.S. To analyser Power Module Type 12AK Power Batt. SysCh. -
Page 30: Technical Specifications
Hearing-Protector Test Fixture Type 45CA Technical Specifications Built in accordance with: ISO 4869-3 (can also be used with two microphones for binaural testing) Weight: 11.6 k g Dimensions (in millimeters and inches): 155.60 mm (6.13’’) G.R.A.S. ISO 4869-3 Hearing-protector Test Fixture Type 45CA Serial No. XXXXX 53.00 mm Ø... -
Page 31: What To Order
What to Order The Type 45CA Package IEC 60711 Configuration • Hearing-protector Test Fixture ..Type 45CA Externally Polarized Configuration*: • Ear-canal extension ....GR1069 • Blind plug ..... . . GR1079 • IEC 60711 Ear Simulator .