MIL-DTL-24643C
4.8.31.5 Further procedure (may not be required, see 4.8.31.4). An additional specimen, which shall consist of
a piece of insulated conductor (including insulation covering) of not less than 10 feet in length, shall be prepared.
This entire specimen, except for the extreme ends (which shall be exposed to air), shall be submerged in gentian
violet for a period of not less than 30 minutes. To facilitate submersion the specimen may be coiled to the extent
that nowhere bent along a radius of less than 12 times the maximum measured specimen diameter. The specimen
shall then be removed from the gentian violet and visually inspected for defects.
4.8.31.6 Further observation. Specimen failure shall be construed if the insulation covering of the specimen
exhibits an average of more than one pinhole, which allows penetration of the gentian violet for each 12 inches of
length.
4.8.32 Thermoset proof. The hot creep test shall be in accordance with ICEA T-28-562. The test shall be
performed as specified for thermoset insulations. The procedure for jacket testing shall be modified to run at
200 °C. Jacket percent of elongation shall be as specified in the individual specification sheets (see 3.1).
4.8.33 Electrical moisture absorption. The test shall be performed in accordance with ICEA T-27-581/NEMA
WC 53-2000, except with the following requirements. The test shall be performed on a 14 AWG wire. The
insulation thickness shall be 0.045±0.004 inch. There shall be no separator between the conductor and insulation,
and no coverings over the insulation(s). The wire sample shall be at least 15feet long. The middle 10 feet of the
sample shall be immersed in tap water that is maintained at the temperature specified for the insulation or composite
insulation being tested for a period of 14 days, keeping not less than 2.5 feet at each end above water as leakage
insulation. The test shall be performed in water at 75 °C. The water level shall be kept constant. The capacitance
of the insulation shall be determined at an average stress of 80 kV/in at approximately 60 Hz after 1, 7, and 14 days
immersion. The increase in capacitance from 1 to 14 days and from 7 to 14 days shall be expressed as a percentage
of the 1 and 7 day values, respectively.
4.8.34 Temperature/humidity. When specified, the cable shall be tested in accordance with EIA 364-31B,
humidity test procedure, Method IV, with a cold temperature step. After completion of the testing, the cable shall be
allowed to return to 20 °C and must meet the cable attenuation requirements specified in the applicable specification
sheet.
4.8.35 Aging stability. When specified (see 3.1), the inspection shall be in accordance with MIL-DTL-17.
4.8.36 Dimensional stability. When specified (see 3.1), the inspection shall be in accordance with
MIL-DTL-17.
4.9 Test methods (electrical).
4.9.1 Attenuation. This test shall determine the ability of completed cable, which is intended for the
transmission of data, voice, or control information, to propagate a signal at a specific frequency without causing an
unacceptable reduction of signal amplitude.
4.9.1.1 Specimen. The specimen shall consist of a piece of completed cable, which shall have sufficient length
to exhibit an electrical attenuation of not less than 3 decibels (dB) at the specified test frequency (see 3.1).
Individual transmission lines within this specimen (where each single insulated conductor plus surrounding shield or
each insulated conductor pair plus surrounding shields is considered to be a transmission line) shall be selected for
testing as follows:
a.
Specimens containing four or fewer transmission lines - every transmission line shall be tested.
b. Specimens containing more than four but fewer than 21 transmission lines - Four different transmission
lines shall be tested. Not fewer than one of these transmission lines shall be selected from each concentric cabling
layer within the specimen.
c. Specimens containing 21 or more transmission lines - The number of transmission lines tested shall be
equal to the square root (rounded, if necessary, to the nearest whole number) of the total number of transmission
lines. Not fewer than one of these transmission lines shall be selected from each concentric cabling layer within the
specimen.
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