GRAS 45AA Telephone Test Head
IEC 60318 or IEC 60711 depending on configuration
The GRAS 45AA Telephone Test Head is a tailor-made fixture for testing the acoustic performance of telephone handsets in accordance with international standards and recommendations. The design of the GRAS 45AA combines precision with a robust construction to ensure stability and reproducible test results with a minimum of acoustic interference.
Technology
When used with GRAS 43AD articitial ear or GRAS 43AE IEC 60711 ear simulator, and a GRAS 44AA/GRAS 44AB mouth simulator, it can be set up for testing telephone handsets in accordance with ITU-T recommendations.
Positioning of the mouth
Four different, detachable precision brackets are provided for mounting the Mouth Simulator according to the standardised positions shown in the table for speaking into a telephone. These positions are maintained to within an accuracy of 1 mm. Reference gauges are available for verifying this.
| Speaking Position | Recommendation |
| LRGP | ITU-T Rec. P76 |
| AEN | ITU-T Rec. P76 |
| HATS | ITU-T P58 |
| REF | OREM A |
Anti-vibration Mounts
The GRAS 45AA stands on four anti-vibration mounts to isolate it from extraneous vibrations which could otherwise lead to spurious measurement results.
Handset Alignment
The GRAS 45AA is provided with graduated guides and stops for aligning a telephone handset correctly in position over the Artificial Ear. Lateral guides are independently adjustable to cater for asymmetrical handsets.
Once aligned, an adjustable spring-loaded, padded clamp will hold the handset in position. As specified in some tests, an adjustable force may also be applied by adding a small mass to the measurement object.
Specifications
Ordering info
Included items
| - |
4 different brackets for selecting direction of the Mouth Simulator |
Optional items
Notice that for creating a complete order list you need to find relevant accessories for the chosen
GRAS 44AA, 44AB, 43AD and 43AE products. See www.gras.dk.
For test of the microphone in the handset
| GRAS 44AA |
Mouth Simulator (with built-in amplifier) |
| GRAS 44AB |
Mouth Simulator |
For test of the earpiece in the handset
| GRAS 43AD |
Artificial Ear for Telephone Test Head (IEC 60318) |
| GRAS 43AE |
Ear Simulator (IEC 60318-4). Includes GRAS RA0056 Low-Leak Pinna Simulator & RA0057 High-Leak Pinna Simulator |
For verifying the position (AEN & REF) of the Mouth Simulator
| GRAS RA0141 |
Reference Gauges |
GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.
