GRAS RA0045 Externally Polarized Ear Simulator According to IEC 60318-4 (60711)

Volume: 1260 mm³ @ 500 Hz
Dyn range: 25 dB(A) to 164 dB
IEC: 60318-4

GRAS RA0045 Externally Polarized Ear Simulator According to IEC 60318-4 (60711)

Technology

Introduction

The RA0045 Ear Simulator is for making acoustic measurements on earphones coupled to the human ear by ear inserts such as tubes, ear moulds, or ear tips. The acoustic input impedance of RA0045 closely resembles that of the human ear and, as a result, loads a sound source in very much the same way.

The RA0045 complies with the following international requirements:

  • IEC 60318-4: Occluded-ear simulator for the measurement of earphones coupled to the ear by ear inserts.
  • ITU-T Recommendations P.57 (08/96) Series P: Telephone transmission quality, Objective measuringapparatus: Artificial ears.

It is measured and calibrated according to the ITU-T Recommendation P.57.

Design

The RA0045 embodies a number of carefully designed volumes connected via well-defined and precisely tuned resistive grooves. In an equivalent electrical circuit, capacitors would represent the volumes, and inductance and resistance would represent respectively air mass and air flow within the resistive groves.

It is delivered with a built-in GRAS 40AG 1/2" externally polarized pressure microphone and an individual calibration chart for the ear simulator.

Typical Applications and Use

The RA0045 is for measurements on earphones and hearing aids coupled to the human ear by ear inserts such as tubes, ear moulds, or ear tips.

In accordance with ITU-T Recommendation P.57, it can be used with the following GRAS pinna simulators for testing telephones:

It is also part of the GRAS 43AC Artificial Ear which is a complete test jig for acoustic testing of earphones coupled to the ear by inserts.

A comprehensive range of accessories for making measurements in accordance with IEC 60318-4 are available. See the tab Ordering info.

Compatibility

The RA0045 can be used with a standard LEMO preamplifier, e.g. the GRAS 26AK 1/2" Preamplifier or the GRAS 26AC 1/4" Preamplifier fitted with an adapter. For the 1/4" preamplifier, use either the straight RA0003 Adapter or the right-angled RA0001 Adapter.

Specifications

Theoretical dynamic range lower limit with GRAS preamplifier
dB(A)
25
Theoretical dynamic range upper limit with GRAS preamplifier @ +28 V / ±14 V power supply
dB
153
Theoretical dynamic range upper limit with GRAS preamplifier @ +120 V / ±60 V power supply
dB
164
Resonance frequency
kHz
13.5
Coupler volume
mm³
1260 @ 500 Hz
Temperature range, operation
°C / °F
-30 to 60 / -22 to 140
Temperature coefficient @250 Hz
dB/°C / dB/°F
0.05
Humidity range non condensing
% RH
0 to 75
ANSI standard
S3.7
IEC standard
60318-4 (former 60711)
ITU-T recommondations
P.57
CE/RoHS compliant/WEEE registered
Yes/Yes,Yes
Weight
g / oz
52 / 1.8
Specification Conditions

Typical frequency response

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

Dimensions

Ordering info

 Optional items

GRAS RA0088

In Ear Adapter

GRAS GR0433

Calibration Adapter

GRAS GR0434

Stop Washer

GRAS GR0436

Tube Adapter

GRAS GR0437

Ear-mould Simulator

GRAS GR0438

Retention Ring

GRAS GR0440

Tube Adapter

GRAS RA0056

Low-leak Pinna Simulator

GRAS RA0057

High-leak Pinna Simulator

GRAS 26AK

26AK 1/2'' Standard Preamplifier with Integrated Connector

GRAS 26AC

26AC 1/4" Standard Preamplifier with 3 m Integrated Cable

GRAS RA0001

Right-angled Adapter for 1/2" microphone and 1/4" preamplifier

GRAS RA0003

Adapter for 1/2" microphone and 1/4" preamplifier

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

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