MIL-PRF-87819 Headset-Microphone, \(Hearing Protective Type, High And Moderate Ambient Noise Levels\), General Specification ForThis specification covers the requirements for headset-microphone with rigid headband. These parts meet established requirements for communications equipment used to protect against hazardous noise exposure, and are approved for use in certain high and moderate ambient noise level applications \(see 6.1\). The term headset is to be used interchangeably for headset-microphone and is used when referring to any of the articles covered in this specification.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11

MIL-PRF-87819B

FIGURE 3. Temperature shock.

4.7.11 Humidity (see 3.5.10). The headset-microphone shall be tested in accordance with method 103

of MIL-STD-202, test condition B. Upon completion of the test, the acoustic quality test as specified in

4.7.2 and the visual and mechanical examination shall be performed as specified in 4.7.1.

4.7.12 Twist and pull test. The cable assembly pull test shall consist of the twist test (4.7.12.1)

followed by the pull test (4.7.12.2) performed three times. Upon completion of the tests specified, the

cable assembly shall meet the requirements of 3.5.11.

4.7.12.1 Twist test. The twist test shall be applicable to all ends of the cable assembly that are

terminated with a connector only. Each connector shall be secured in a holding device in such a way that

it can not rotate. The twist shall be applied about the axis of the cable to cause a point on the cable 3

inches from the connector to twist 180 degrees from the starting position and held there for 30 seconds.

The cable shall then be twisted in the opposite direction such that the point on the cable has twisted 180

degrees past the original staring position, and be held there for 30 seconds.

4.7.12.1.1 Twist test (short cable). The twist (short cable) shall be applicable to the short cable

termination into the headset on one end and terminating with a connector on the other end. The

connector shall be secured in a holding device in such a manner that it can not rotate. The twist shall be

applied about the axis of the cable to cause a point on the cable to twist 90 degrees from the starting

point and held for 30 seconds. The cable shall be twisted in the opposite direction such that the point on

the cable has twisted 90 degrees past the original starting position, and be held there for 30 seconds.

4.7.12.2 Pull test. The pull test shall be applied to all connectors and the physical locations where the

cables are attached. The component of the cable assembly to be tested shall be secured in a stationary

holding device and the cable gripped 6 inches to 12 inches from the component of the cable assembly

under test. The grips shall not slip or damage the cable during the test. The static force shall be applied

for 30 seconds with a pull force of 20 pounds. Connectors that are potted or molded with bonded bend

reliefs or bonded strain reliefs shall have a pull force of 30 pounds applied.

4.7.13 Headband pressure (see 3.5.12). The headset pressure shall be tested by use of an apparatus

equivalent to the pressure-measuring device specified on figure 4. As specified on figure 2, the "A"

dimension of the headset shall be adjusted to 6.10 inches (155 mm), and the "B" dimension adjusted to

represent an approximate midpoint of the headband extension range. The pressure shall then be

measured from the strain gauge.