MIL-DTL-757C
styphnate, at the completion of this operation. Thoroughly rinse the brush to ensure that lead
styphnate particles are removed. After the final rinse, a small presence of visible lead styphnate
on the sieve shall be cause for rejection of the lot.
4.4.5.1 Granulation (alternate method). Determine lead styphnate particle size
distribution using a Microtrac II or equivalent commercially available laser particle size analyzer
which has been calibrated using appropriate procedures. Follow sample preparation and
instrument operating procedure from the analyzer manufacturer. Only distilled or de-ionized
water shall be allowed to be used as liquid medium, if a liquid medium is used to "wet" and
disperse a powdered sample. No vigorous physical action, which may cause particle size
attrition, shall be performed on the sample prior to loading into the instrument. Analyzer shall be
configured to measure longest axis in the sample.
4.4.6 Apparent density. Place 3 mL of n-butyl alcohol into a 5 mL graduate which has an
internal diameter of about 7.5 mm and is graduated in 0.05 mL divisions. Add approximately 2 g
of the dry sample weighed to the nearest 1 mg in small portions and wash down the walls of the
graduate with n-butyl alcohol. To insure that the entire sample is wetted, shake the graduate
carefully by slowly inverting it at least five times. Adjust the volume by adding butyl alcohol to
the 5 mL mark. Allow the graduate to stand for 3 hours and note the volume occupied by the
solid material. Calculate the apparent density as follows:
W
Apparent density =
V
where: W = weight of sample, g
V = observed volume, mL
4.4.6.1 Apparent density (alternate method). Transfer approximately 2 to 3 g of the wet
sample obtained in 4.3.3.1 into a Buchner funnel fitted with medium porosity filter paper.
Rinse the wet sample with denatured ethyl alcohol to displace water. Rinse the sample with n-
butyl alcohol to displace the denatured ethyl alcohol. Transfer the sample to a 5 mL or 10 mL
graduate, having 0.1 mL graduations. Rinse down the sides of the cylinder with enough n-butyl
alcohol to slurry the sample. Stir with a wooden stick, or agitate by some means in order to free
any trapped air bubbles. Fill to the top cylinder graduation with n-butyl alcohol as accurately as
possible, being sure the sides are rinsed clean. Weigh the cylinder and contents to the nearest mg.
Record this weight as W1. Allow the cylinder contents to settle for a minimum of 2 hours, then
note volume occupied by the sample. Record this volume as V. Determine the weight of the
cylinder filled to the top cylinder graduation with n-butyl alcohol only (no sample) to the nearest
1 mg. Record this weight as W2. Calculate the apparent density as follows:
Ds(W 1 - W 2)
Apparent density =
V ( Ds - Db)
where: Ds = Density of normal lead styphnate
Db = Density of N-butyl alcohol
8
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business