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45CA-9 and 45CA-10
RA0401/0402 High-Frequency Ear Simulator
Standards
IEC 60318-4
Occluded-ear simulators for the measurement of earphones coupled to the ear by
ear inserts
ITU-T Recommendation P.57
Series P: Telephone transmission quality, Objective measuring apparatus: Artificial ears
ANSI S3.25/ASA-2009
American National Standard For an Occluded Ear Simulator
Frequency Response
Typical transfer impedance
re 500 Hz
Resonance frequency
13.5 kHz ± 1 kHz
Sensitivity
Sensitivity
12.5 mV/Pa
Dynamic Range
RA0401 (LEMO)
25 dBA to 164 dB
RA0402 (CCP)
25 dBA to 153 dB
Effective Volume
at 500 Hz
1260 mm
3
Dimensions
Height
23.0 mm
Diameter
23.75 mm
-5
5
15
25
35
45
55
100
1000
10000
d
B
r
e
5
00
H
z
Frequency [Hz]
Typical response
Tolerance
Instruction Manual
3 2 | GRAS 45CA Headphone/Hearing-protector Test Fixture