BRUEL & KJAER 4185, User Manual

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Chapter 3 – Handling the Ear Simulator
13 Ear Simulator for Telephonometry Type 4185
User Manual
Fig.3.2 Use of the frequency response curve to assist in obtaining a good acoustic seal
between the handset earcap and the coupler
3.3 Protecting the Ear Simulator
When not in use, the ear simulator should be protected against dust
that could otherwise block the small holes in the coupler and the
microphone and affect the performance.
3.4 More Information
For more helpful hints in using Brüel & Kjær ear simulators for
telephone testing, see the application note, “Improving Telephone
Handset Performance” (BO 0455) included with your instrument.
921743
B: Frequency Response, Magn. dB re 1.000 Pa/Pa
10
0
– 10
– 20
– 30
dB
Application Examples: Receive Measurements
RLR – 6.43 dB — F
RLR – 9.85 dB — P
200 500 1 k 100 2 k 5 k 10 k Hz
Mode: SSR
Sealed
With leak