Test Procedures; Definitions - Bose T5 Service Manual

Note: The following procedures contain two
separate test procedures.
The first test is for internal Bose
centers that have the required Bose final
audio test system.
The second test procedure is a less complex
light-up-and-play type test for repairs per-
formed in the field.
Internal Bose Repair Center Tests
Equipment Required
The following hardware and software are
needed to perform the tests described
herein. Equivalent hardware may be substi-
tuted.
IMPORTANT NOTE: These products are
RoHS compliant. Use ONLY lead free
solder when making repairs.
Bose Final Audio Test System
This system connects to the headset and
provides all stimulus signals necessary to
excite the headset for listening tests.
The room in which tests are performed must
be within the following range of environmen-
tal conditions:
• Temperature - between 62°F and 82°F
•
Humidity - between 10% and 90% R.H.
•
Ambient Noise - less than 45 dB(C)SPL
•
Noise Signal for noise attenuation listening.
- The test system must produce broad
band noise, 50 Hz to 10 kHz, approxi-
mately pink (third-octave spectrum flat
vs. frequency) below 1 kHz and third-
octave spectrum weighted approximately
inversely with frequency above 1 kHz,
overall level 94 dB SPL ±3 dB. Duration
of 30 minutes or more and must not
repeat more than one time during that
interval.

TEST PROCEDURES

® repair
20
Test Setup
• Install two AA batteries into the control
module for talk through capability.
• Connect the headset to the
intercommunications system

Definitions

Background Noises Noise present in the
absence of other excitation, including the
following:
• Hum Constant low frequency signal,
caused by power line interference.
• Hiss Steady, broad mid-to-high frequency
signal caused by noise of headset electron-
ics.
• Static Intermittent crackling signal, caused
by external electrical interference.
• Whine Sharp continuous signal, caused by
narrow overvoltage pulses on power line.
• Ripple Noises caused by interference on
power supply line at various frequencies.
Instability Noises related to acoustic leaks
or malfunctions compromising stability,
including the following:
• Squeal Mid-to-high frequency variable
tone.
• Motor-boating Lower frequency periodic
noise.
• Buzz Harmonic produced by vibration in
the presence of an audio signal. This noise
is usually related to mechanical faults.
Overload Noises related to movement,
pressure or impact on headset as well as
extremely high external noise, including the
following:
• Click Sharp transient caused by collapse
of driver diaphragm. Generally very notice-
able.
• Thump Low frequency transient, caused
by saturation of headset electronics.
• Pop Low frequency transient, caused by
saturation of ANR loop.