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|  MIL-DTL-60426B(AR)
W/AMENDMENT 1
units. Accuracy of densitometer shall be maintained by calibrating with a photographic step
tablet at the start, middle, and end of each shift and at any time that the densitometer is turned off
and started prior to taking any readings. Calibration shall be made at a step tablet density level
within .5D of that being measured on the radiographic film. Each point of density measurement
on the radiographs shall be identified by a circumscribed circle (made with a suitable pen or
pencil) of no more than 1/4 inch in diameter. All photographic step tablets used in normal
operation shall be checked for accuracy monthly by calibrating the densitometer with a reference
photographic step tablet. Reference tablet shall be kept available, but shall be protected from
wear and damage and shall not be used in daily operations. Any photographic step tablet having
severe surface damage or showing a deviation from previous calibrations by .05D or more shall
be replaced with a new, unused step tablet.
4.4.2 Composition test. Eight burster tubes shall be randomly selected from each
inspection lot. An inspection lot shall be one week's production or 1,000 bursters, whichever is
less. In addition, one burster tube shall be randomly selected from the first 20 burster tubes
poured from the first kettle of the inspection lot and one burster tube shall be randomly selected
from the last 20 burster tubes poured from the last kettle of the inspection lot. Two samples of
composition B-5 shall be taken from each of the ten burster tubes per inspection lot. One
sample shall be taken from an area located one inch from the top of each tube. A second sample
shall be taken from an area located one inch from the bottom of the same tube. This procedure
shall yield 20 samples (two separate samples for each burster tube). If any one sample fails to
comply with any of the requirements specified, the burster tube inspection lot shall be rejected.
The tests shall be performed as specified in 4.4.2.1 4.4.2.6. The resin in the sample explosive
compositions shall be fully cured. A minimum cure of 7 days at room temperature or 48 hours
at + 140 degrees F is recommended.
4.4.2.1 Composition test scope. This gravimetric method is designed for the analysis of
the three components TNT, RDX, (with HMX) and cured resin. It consists of solvent extractions
of Composition B-5 samples using 1,2 dichloroethane saturated with RDX and HMX for the
TNT (filtrate determined for TNT by UV spectroscopy) and acetonitrile for the cured resin. The
RDX content is determined by weight differences. A polypropylene (PPE) filter medium will be
used in this gravimetric method.
4.4.2.2 Specimen. Samples of Composition B-5 shall be ground in a Wiley Mill using a
20 mesh screen. After grinding, mix the sample thoroughly to obtain a uniform representative
sample.
4.4.2.3 Apparatus
a. Wiley Mill with 20 mesh screen.
b. Vacuum filtration system (consisting of pump, hosing and cold traps).
c. Kontes 1000 ml filtering dome or equivalent.
d. A Milipore 47 mm filtration system (top funnel coated with Teflon on the bottom
surface and a bottom metal screen filter support).
e. Conical 50 ml graduated cylinder.
f. Beakers (sizes 50ml, 100ml).
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