GRAS RA0045-S1 Prepolarized Ear Simulator According to IEC 60318-4 (60711)

Volume: 1260 mm³ @ 500 Hz
Dyn range: 25 dB(A) to 150 dB
Sensitivity 12.5 mV/Pa
IEC: 60318-4

GRAS RA0045-S1 is an ear simulator with an acoustic input impedance closely resembling that of an average human ear. The RA0045 includes a 40AO 1/2" prepolarized pressure microphon and each RA0045 is individually calibrated with this specific microphone.

Technology

Introduction

The RA0045-S1 Prepolarized 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-S1 closely resembles that of the human ear and, as a result, loads a sound source in very much the same way.

The RA0045-S1 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-S1 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 40AO 1/2" prepolarized pressure microphone and an individual calibration chart for the ear simulator.

Typical Applications and Use

The RA0045-S1 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-S1 Artificial Ear.

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

Compatibility

The RA0045-S1 can be used with a standard CCP preamplifier, e.g. the GRAS 26CA 1/2" Preamplifier or the GRAS 26CB 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

Polarization/Connection
0 V / CCP
Theoretical dynamic range lower limit with GRAS preamplifier
dB(A)
25
Dynamic range upper limit with GRAS CCP preamplifier
dB
150
Set sensitivity @ 250 Hz (±3 dB)
mV/Pa
12.5
Set sensitivity @ 250 Hz (±3 dB)
dB re 1V/Pa
-38
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 90
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


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 26CA

26CA 1/2'' CCP Standard Preamplifier with BNC Connector

GRAS 26CB

26CB 1/4" CCP Standard Preamplifier with Microdot Connector

GRAS RA0001

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

GRAS RA0525 Foam insert for 60318-4 coupler, 10 pcs

GRAS RA0003

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

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