G.R.A.S. 45CA Headphone/Hearing-protector Test Fixture

ISO: 4869-3
IEC: 60318-1 and 60318-4 depending on configuration

Introduction

G.R.A.S. 45CA provides the basis for reliable and exact measurements and is designed with

  • A test fixture mounted on a resilient base that reduces the noise floor to a minimum in a typical test situation. Foam plugs and grease are supplied to avoid sound leakage along the cable
  • A test fixture head, made for optimizing the acoustic isolation
  • An acoustic cup and plug for testing the acoustic isolation
  • A range of moulded-rubber KEMAR pinnae, e.g. for testing ear plugs, can be fitted

The 45CA’s robust design is ideally suited for binaural testing of active and passive earplugs, as well as circumaural hearing protectors.

It is primarily intended for testing the performance of hearing-protection devices such as ear plugs and ear muffs (supra-aural and circum-aural) but can also be used for testing sound sources such as earphones and headphones. It is fitted with either microphones or ear simulators, depending on the device to test and the standard to comply with.

Compliance with ISO 4869-3, IEC 60318-1 and IEC 60318-4 assures technicians, decision makers, and authorities of repeatability and transparent data when developing and verifying hearing protectors.

The pinnae for the 45CA are basically the same as the standardized KEMAR pinnae, but rounded to fit the large 45CA base plate. This large base plate reduces or eliminates the risk of leakage.

The 45CA includes two plugs for measuring the acoustic isolation in a closed ear.

We recommend calibration prior to each use to ensure the accuracy of your measurements. The G.R.A.S. 42AP Intelligent Pistonphone or the G.R.A.S. 42AA Pistonphone are ideally suited for this task.

Typical applications and use

45CA Headphone/Hearing-protector Test Fixture, Non-configured is a versatile test platform that you can configure to suit specific needs. The most common configurations can be ordered fully assembled, calibrated and tested from G.R.A.S. These are:

45CA-1 Headphone/Hearing-protector Test Fixture, ISO 4869-3 1" Mic. LEMO

The 45CA-1 is a configuration for testing of outside-the-ear devices, i.e. for measuring the insertion loss of ear muffs and the sound quality of headphones. In this configuration, 45CA is configured with two G.R.A.S. 40EN 1" pressure microphones. The configuration conforms with ISO 4869-3.


45CA-2 Headphone/Hearing-protector Test Fixture, ISO 4869-3 1/2" Mic. CCP

The 45CA-2 is a configuration for testing of outside-the-ear devices, i.e. for measuring the insertion loss of ear muffs and the sound quality of headphones. In this configuration, 45CA is configured with two G.R.A.S. 40AD 1/2" pressure microphones. This configuration conforms with ISO 4869-3


45CA-3 Headphone/Hearing-protector Test Fixture, IEC 60318-1 LEMO

45CA-3 is configured for measurement of insertion loss of circum-aural hearing protectors and the sound quality of headphones, with two RA0039 Ear Simulators with 40AG 1/2" externally polarized microphones. The configuration conforms with IEC 60318-1. The RA0039 cannot be used with a pinna simulator, and therefore cannot be used for measuring in-ear earphones.


45CA-4 Headphone/Hearing-protector Test Fixture, IEC 60318-1 CCP

The 45CA-4 is configured with two RA0039 Ear Simulators with 40AO 1/2" prepolarized microphones. The configuration complies with IEC 60318-1 and is used for measurements of insertion loss of circum-aural hearing protectors and sound quality of headphones. The RA0039 cannot be used with a pinna simulator, and therefore cannot be used for measuring in-ear earphones.


45CA-5 Headphone/Hearing-protector Test Fixture, IEC 60318-4 LEMO

The 45CA-5 is configured with RA0045 externally polarized ear simulators for use with pinna simulators. It can be used for measurements of the insertion loss of ear muffs and ear plugs, and the sound quality of earphones and headphones. The configuration complies with IEC 60318-4.


45CA-6 Headphone/Hearing-protector Test Fixture, IEC 60318-4 CCP

The 45CA-6 is configured with RA0045-S1 prepolarized ear simulators for use with pinna simulators. This configuration can be used for measurements of the insertion loss of ear muffs, sound quality of earphones and  hearing aids. The configuration complies with IEC 60318-4.

The application specific items for each of these configurations are listed under the tab Ordering Information.

System verification

For daily verification and check of your measurement setup, we recommend using a calibrator like G.R.A.S. 42AB Sound Calibrator.

For proper sensitivity calibration, we recommend using a pistonphone like G.R.A.S. 42AP Intelligent Pistonphone.

Service

If you accidentally damage the diaphragm on a G.R.A.S. microphone, we can—in most cases—replace it at a very reasonable cost and with a short turn-around time. This not only protects your investment, but also pleases your quality assurance department because you don’t have to worry about new serial numbers, etc.

Calibration

Before leaving the factory, all G.R.A.S. microphones are calibrated in a controlled laboratory environment using traceable calibration equipment.

Depending on the use, measurement environment, and internal quality control programs, we recommend recalibrating the microphone at least once a year.

Performance and warranty

The G.R.A.S. 45CA is made of components from our standard portfolio and are all manufactured of high-quality material and branded parts that were chosen and processed to ensure life-long stability and robustness. This enables us to offer 2 years warranty against defective materials and workmanship.
Exceptions: Microphones included in 45CA as for these our normal 5 year warranty apply. The warranty period for cables is 6 months.

IEC standard Dep. on conf.
ITU-T recommondations P.380
CE/RoHS compliant/WEEE registered Yes/Yes/Yes
Weight g / oz 11.6 k / 409.18

45CA-1 and 45CA-2

Self Insertion Loss, Measured with closed ear simulators: 80 - 250 Hz > 50 dB

Self Insertion Loss, Measured with closed ear simulators: 350 - 4000 hz > 65 dB

Self Insertion Loss, Measured with closed ear simulators: 5000 - 20000 Hz > 55 dB

 

Specs for the G.R.A.S. 40EN 1" Externally Polarized Pressure Microphone can be found here.

Specs for the G.R.A.S. 40AD 1/2" Prepolarized Pressure Microphone can be found here.

 

45CA-3 and 45CA-4

Specs for the G.R.A.S. RA0039 Ear Simulator can be found here.

Specs for the G.R.A.S. 40AG 1/2" Externally Polarized Pressure Microphone can be found here.

Specs for the G.R.A.S. 40AO 1/2" Prepolarized Pressure Microphone can be found here.

 

45CA-5 and 45CA-6

Specs for the G.R.A.S. RA0045 Ear Simulator can be found here.

Specs for the G.R.A.S. RA0045-S1 Ear Simulator can be found here.

 

G.R.A.S. Sound & Vibration reserves the right to change specifications without notice.

Included items with G.R.A.S. 45CA

Common to all configurations - and delivered when ordered non-configured

G.R.A.S. GR1085 Cover Plate, 2 pcs
G.R.A.S. GR0970 Insert
G.R.A.S. GR0974 Acoustic Cup (for acoustic isolation testing)
G.R.A.S. RA0178 1'' Acoustic Plug
G.R.A.S. GR1281 Foam plug for leakage sealing (2 pcs)
G.R.A.S. MI0016 7 ml Silicon grease for leakage sealing
G.R.A.S. YY0019 Allen Key, 6 mm
G.R.A.S. YY0016 Allen Key, 2.5 mm
G.R.A.S. YY0018 Allen Key, 2 mm
G.R.A.S. YY0022 Allen Key, 1.5

 

Configurations

Six different pre-configurations of 45CA are available. Each of these are sold fully assembled and tested, ready for use.

45CA-1 1” Headphone/Hearing-Protector Test Fixture, ISO 4869-3 1" Mic. LEMO
For test of ear muffs

G.R.A.S. 40EN 1" Ext. Polarized Pressure Microphone (2 pcs)
G.R.A.S. RA0017 Adapter for 1" microphone and 1/2" preamplifier (2 pcs)
G.R.A.S. RA0003 Adapter for 1/2" microphone and 1/4" preamplifier (2 pcs)
G.R.A.S. 26AS 1/4" Standard Preamplifier with 3 m integrated cable, very short (2 pcs)

 

45CA-2 1/2” Headphone/Hearing-Protector Test Fixture, ISO 4869-3 1/2" Mic. CCP
For test of ear muffs

G.R.A.S. 40AD 1/2" Prepolarized Pressure Microphone, High Sensitivity (2 pcs)
G.R.A.S. RA0177 1” Microphone protection grid (2 pcs)
G.R.A.S. RA0058 1/2'' to 1'' Microphone Adapter (2 pcs)
G.R.A.S.GR0010 1/2" to 1/4" Adapter (2 pcs)
G.R.A.S. 26CS 1/4" CCP Preamplifier with Microdot connector, very short (2 pcs)
G.R.A.S. AA0070 3 m Microdot - BNC Cable (2 pcs)

 

45CA-3 Headphone/Hearing-Protector Test Fixture, IEC 60318-1 LEMO
For test of ear muffs and headphones

G.R.A.S. RA0039 Ear Simulator according to IEC 60318-1 (2 pcs)
G.R.A.S. 40AG 1/2" Ext. Polarized Pressure Microphone (2 pcs)
G.R.A.S. RA0176 1/2'' to 1'' Adapter for RA0039 (2 pcs)
G.R.A.S. GR0010 1/2" to 1/4" Adapter (2 pcs)
G.R.A.S. 26AS 1/4" Standard Preamplifier with 3 m integrated cable, very short (2 pcs)

 

45CA-4 Headphone/Hearing-Protector Test Fixture, IEC 60318-1 CCP
For test of ear muffs and headphones

G.R.A.S. RA0039 Ear Simulator according to IEC 60318-1 (2 pcs)
G.R.A.S. 40AO 1/2" Prepolarized Pressure Microphone (2 pcs)
G.R.A.S. RA0176 1/2''-1'' Adapter for RA0039 (2 pcs)
G.R.A.S. GR0010 1/2" to 1/4" Adapter (2 pcs)
G.R.A.S. 26CS 1/4" CCP Preamplifier with Microdot connector, very short (2 pcs)
G.R.A.S. AA0070 3 m Microdot - BNC Cable (2 pcs)

 

45CA-5 Headphone/Hearing-Protector Test Fixture, IEC 60318-4 LEMO
For test of ear muffs, ear plugs, headphones and ear phones

G.R.A.S. KB0070 Large Right KEMAR Pinna, 55 Shore OO
G.R.A.S. KB0071 Large Left KEMAR Pinna, 55 Shore OO
G.R.A.S. GR1075 Pinna Holder Plate
G.R.A.S. GR1069 Ear Canal Extension
G.R.A.S. RA0045 Externally Polarized Ear Simulator according to IEC 60318-4 (60711) (2 pcs)
G.R.A.S. GR0010 1/2" to 1/4" Adapter
G.R.A.S. 26AS 1/4" Standard Preamplifier with 3 m integrated cable, very short (2 pcs)

 

45CA-6 Headphone/Hearing-Protector Test Fixture, IEC 60318-4 CCP
For test of ear muffs, ear plugs, headphones and ear phones

G.R.A.S. KB0070 Large Right KEMAR Pinna, 55 Shore OO
G.R.A.S. KB0071 Large Left KEMAR Pinna, 55 Shore OO
G.R.A.S. GR1075 Pinna Holder Plate (2 pcs)
G.R.A.S. GR1069 Ear Canal Extension (2 pcs)
G.R.A.S. RA0045-S1 Prepolarized Ear Simulator according to IEC 60318-4 (60711) (2 pcs)
G.R.A.S. GR0010 1/2" to 1/4" Adapter (2 pcs)
G.R.A.S. 26CS 1/4" CCP Preamplifier with Microdot connector, very short (2 pcs)
G.R.A.S. AA0018 3 m Microdot - BNC Cable, High Temp (2 pcs)

 

Optional accessories

KEMAR Pinnae for configurations with using IEC 60318-4 Ear Simulator

G.R.A.S. RA0172 Pinna & Ear Simulator Mounting Kit (required to hold a pinna) Included with 45CA-5 and -6.
  Note: Contains a cover plate, ear canal extension, screws and Allen key
G.R.A.S. KB0070 KEMAR Large Right Ear Shore 55 Hearing Protector. Included with 45CA-5 and 6.
G.R.A.S. KB0071 KEMAR Large Left Ear Shore 55 Hearing Protector. Included with 45CA-5 and 6.
G.R.A.S. KB1070 KEMAR Large Right Ear Shore 35 Hearing Protector
G.R.A.S. KB1071 KEMAR Large Left Ear Shore 35 Hearing Protector
G.R.A.S. KB0072 KEMAR Small Right Ear Shore 55 Hearing Protector
G.R.A.S. KB0073 KEMAR Small Left Ear Shore 55 Hearing Protector

 

Cables for LEMO configurations

G.R.A.S. AA0008 3 m LEMO 7-pin - LEMO 7-pin Cable
G.R.A.S. AA0009 10 m LEMO 7-pin - LEMO 7-pin Cable
G.R.A.S. AA0020-CL Customized length LEMO 7-pin - LEMO 7-pin Cable (specify length in cm, e.g. -CL0500 for a 5 m cable)

 

Cables for CCP configurations

G.R.A.S. AA0035 3 m BNC - BNC Cable
G.R.A.S. AA0037 10 m BNC - BNC Cable
G.R.A.S. AA0039-CL Customized length BNC - BNC Cable (specify length in cm, e.g. -CL0500 for a 5 m cable)
G.R.A.S. AE0074 BNC – BNC adapter

 

Power modules

G.R.A.S. 12AQ For all configurations (dual channel LEMO/CCP)
G.R.A.S. 12AA For externally polarized configurations only (dual channel)
G.R.A.S. 12AU 1-Channel Universal Power Module with signal conditioning and power amplifier

 

Power Supply +15 VDC (provides +15 VDC power to the Power Module)

G.R.A.S. AB0002 Mains/line power supply, 230 VAC (EU mains connector)
G.R.A.S. AB0006 Mains/line power supply, 230 VAC (UK mains connector)
G.R.A.S. AB0003 Mains/line power supply, 120 VAC (US mains connector)

 

Calibration Equipment

G.R.A.S. 42AP Intelligent Pistonphone, Class 0
G.R.A.S. 42AA Pistonphone, Class 1
G.R.A.S. RA0023 Coupler for 1" microphones (Note: RA0023 is included with 42AP but optional for 42AA)
G.R.A.S. RA0287 Calibration Adapter (for in-situ verification of RA0039)
G.R.A.S. RA0157 1/2'' Calibration Adapter for KEMAR Pinna (For the IEC60318-4 configuration only)

G.R.A.S. Sound & Vibration reserves the right to change accessories without notice.