MIL-PRF-87819/1B
Cold-environment
shock test:
The microphone protective shield shall resist damage and separation of
components, when exposed to typical bumping and dropping in arctic
environments. After cooling the headset to 70 degrees F for 30 minutes, it
shall be transferred within 2 (two) minutes to an ambient room temperature
location and immediately dropped 3 (three) times onto a hard surface (concrete
or tile) from a height of 4 (four) feet, striking first on the microphone shield.
Measure distance up to the bottom of the microphone shield. This procedure
shall be repeated for a total of 2 (two) cooling/dropping cycles. Following the
test, the product shall meet the visual and mechanical inspection, and acoustic
quality requirements of MIL-PRF-87819, as well as the following talk-out test in
Subgroup 1 of table II. Connect the headset to equipment necessary to allow the
microphone to transmit through the earphone elements. Verify that voice input to
the microphone transmits clearly through the earphone elements, free of
degradation due to the dropping.
Supersession data:
Headset-microphone PIN M87819/1-01 supersedes headset-microphone PIN
H-133/AIC.
TABLE I. Attenuation values.
Frequency (Hz.)
63
80
100
125
160
200
250
315
Minimum mean attenuation (dB)
8
9
10
12
13
15
17
20
Minimum mean attenuation (dB) with
4
5
6
8
10
12
14
17
1/
Eyeglasses
Frequency (Hz.)
400
500
630
800 1,000 1,250
1,600
Minimum mean attenuation (dB)
23
26
28
30
31
32
32
Minimum mean attenuation (dB) with
20
23
25
27
29
30
30
1/
Eyeglasses
Frequency (Hz.)
2,000 2,500
3,150 4,000 5,000 6,300
8,000
Minimum mean attenuation (dB)
32
32
32
32
32
- 31
30
Minimum mean attenuation (dB) with
32
32
32
31
30
- -28
24
1/
Eyeglasses
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1/ Eyeglasses PIN HGU-4/P shall be as specified in MIL-PRF-87819.
8
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