SC-226 MEETING MINUTES Working Group JANUARY 14 ... - RTCA

RTCA Paper No. 021-13/SC226-010
February 6, 2013
(2) Paragraph 2.2.3 Sensitivity
Sennheiser offered to check with company physicists to determine what the theoretical performance of
their microphones under low pressure conditions would be expected to be.
B/E Aerospace can coordinate test activities to try to determine what the effect on the acoustic source
and the microphone under test would be under altitude conditions.
The same issues pertain to Temperature and Temperature Variation except that the test specifically
refers to the microphone preamplifier (independently of the microphone?). The committee had a range
of interpretations.
2.5.2 Temperature Variation Test
The equipment shall be subjected to the test conditions as specified
in RTCA/DO-160x, Section 5.0.
a. Aircraft Microphones (Except Carbon):
The microphone preamplifier, as a component of the microphone
assembly shall be subjected to this test. During the test, the following
requirements shall be met:
(1) Subparagraph 2.2.2.1 Distortion Characteristics
(2) Subparagraph 2.2.3.1 Sensitivity
Bosch offered to check with the test equipment manufacturer to determine what the performance of
the artificial voice would be expected to be under temperature and temperature variation test
conditions.
Additional question: Why are the Aircraft Headsets, Handsets and Loudspeakers excluded from the
temperature variation test. Bosch, Sennheiser and Bose were asked to check with their engineering
departments to determine a valid reason.
Discussion on RF Interference and 2V/M relaxed noise allowance in Section 2.5.11.
Another issue is the title of “sustained ambient” and “transient”. These do not align with the current
version of DO-160.
The “sustained ambient” and “transient” sections should be combined into one.
Radio Frequency Susceptibility Test (Radiated and Conducted)
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