基于IEC 60318-4（60711）的GRAS RA0045-S4外极化耳模拟器，高灵敏度
Standards: IEC 60318-4 (based on), ITU-T P.57
Eff vol: 1260 mm³ @ 500 Hz
Res freq: 13.5 kHz ±1 kHz
GRAS RA0045-S4 耳模拟器是一种声学输入阻抗与普通人耳非常相似的耳模拟器。RA0045-S4包括一个40AP压力麦克风，每个RA0045-S3都使用该特定麦克风单独校准。
Technology
Introduction
The RA0045-S4 Ext Pol Ear Simulator is a special type of ear simulator for making low level acoustic measurements on earphones coupled to the human ear by ear inserts such as tubes, ear moulds, or ear tips. It has an input impedance closely resembling that of an average human ear, and, as a result, loads a sound source in very much the same way.
It is based on 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-S4 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 includes a GRAS 40AP 1/2" Ext. Polarized Pressure Microphone, High Sensitivity and each RA0045-S4 is individually calibrated with this specific microphone.
Typical Applications and Use
The RA0045-S4 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:
- GRAS RA0056 Low-leak Pinna Simulator
- GRAS RA0057 High-leak Pinna Simulator
A comprehensive range of accessories for making measurements in accordance with IEC 60318-4 are available. See the tab Ordering info.
Compatibility
The RA0045-S4 can be used with a standard LEMO preamplifier, e.g. the GRAS 26AK 1/2" Preamplifier or the GRAS 26AC-1 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
Typical frequency response
GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.
Dimensions
Ordering info
Optional items
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 |
Low-leak Pinna Simulator | |
High-leak Pinna Simulator | |
26AK 1/2'' Standard Preamplifier with Integrated Connector | |
26AC-1 1/4" Standard Preamplifier with 3 m Integrated Cable | |
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.
