G.R.A.S. 45CA Hearing-Protector Test Fixture

ISO: 4869-3
IEC: 60318-1 and 60318-4 depending on configuration
  • 45CA Hearing-Protector Test Fixture

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 design of the 45CA makes this task very easy. 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

The 45CA is primarily intended for testing the performance of hearing-protection devices. However, it is very flexible and can also be configured to test headphones, earphones and hearing-aids. Because the 45CA is built to comply with, or exceed, the ISO 4869-3 standard, it can help manufacturers improve the quality of their products to meet the markets’ and the standards’ growing needs for design, quality assurance, and verified compliance to strict regulations.

Compatibility

The 45CA can be configured with externally polarized microphone(s) or prepolarized microphones for tests according to ISO 4869-3, IEC 60318-1 and IEC 60318-4.

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 45CAEA 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

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

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

G.R.A.S. RA0178 1'' Blind Plug
G.R.A.S. GR0974 Acoustic Cup (for acoustic isolation testing)
G.R.A.S. GR1281 Foam plug for leakage sealing (2 pcs)
G.R.A.S. MI0016 7 ml Silicon grease for leakage sealing
LI0024 Instruction Manual

 

Configurations

The below lists the additional configuration products which are needed for a complete configured system.
Choose the quantity depending on your requirements regarding binaural or only monaural measurements.

1” Hearing-protector testing according to ISO 4869-3 (LEMO)
For test of ear muffs

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

1/2” Hearing-protector testing based on ISO 4869-3 (LEMO)
For test of ear muffs

G.R.A.S. 40AP 1/2" Ext. Polarized Pressure Microphone, High Sensitivity
G.R.A.S. 26AS 1/4" Standard Preamplifier with 3 m integrated cable, very short
G.R.A.S. RA0177 1” Microphone protection grid
G.R.A.S. RA0058 1/2'' to 1'' Microphone Adapter

1/2” Hearing-protector testing based on ISO 4869-3 (CCP)
For test of ear muffs

G.R.A.S. 40AD 1/2" Prepolarized Pressure Microphone, High Sensitivity
G.R.A.S. 26CS 1/4" CCP Preamplifier with Microdot connector, very short
G.R.A.S. RA0177 1” Microphone protection grid
G.R.A.S. RA0058 1/2'' to 1'' Microphone Adapter
G.R.A.S. AA0018 3 m Microdot - BNC Cable, High Temp

 

Headphone testing using IEC 60318-1 Ear Simulator (LEMO)
For test of ear muffs and headphones

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

Headphone testing using IEC 60318-1 Ear Simulator (CCP)
For test of ear muffs and headphones

G.R.A.S. 40AO 1/2" Prepolarized Pressure Microphone, High Frequency
G.R.A.S. 26CS 1/4" CCP Preamplifier with Microdot connector, very short
G.R.A.S. RA0039 Ear Simulator according to IEC 60318-1
G.R.A.S. RA0176 1/2''-1'' Adapter for RA0039
G.R.A.S. AA0018 3 m Microdot - BNC Cable, High Temp

 

Ear- and headphone testing using IEC 60318-4 Ear Simulator and Pinna (LEMO)
For test of ear muffs, ear plugs, headphones and ear phones

G.R.A.S. RA0045 Externally Polarized Ear Simulator according to IEC 60318-4 (60711)
G.R.A.S. 26AS 1/4" Standard Preamplifier with 3 m integrated cable, very short
  Note: Choose optional pinnae & mounting kits according to the table below

Ear- and headphone testing using IEC 60318-4 Ear Simulator and Pinna (CCP)
For test of ear muffs, ear plugs, headphones and ear phones

G.R.A.S. RA0045-S1 Prepolarized Ear Simulator according to IEC 60318-4 (60711)
G.R.A.S. 26CS 1/4" CCP Preamplifier with Microdot connector, very short
G.R.A.S. AA0018 3 m Microdot - BNC Cable, High Temp
  Note: Choose optional pinnae & mounting kits according to the table below

 

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)
  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
G.R.A.S. KB0071 KEMAR Large Left Ear Shore 55 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)

Power Supply +15 VDC (provides 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 RA0023 Coupler for 1" microphones (Note: RA0023 is included with 42AP but optional for 42AA)
G.R.A.S. RA0157 1/2'' Calibration Adapter for KEMAR Pinna (For the IEC60318-4 configuration only)