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|  dissolved, and transfer quantitatively to a
centage of material passing through each
sieve by subtracting from 100. percent the
1,000-ml. volumetric flask, dilute to the mark
with water, and mix thoroughly. Transfer a
sum of the percentages of the material re-
10-ml. aliquot of the solution to a 250-ml.
tained on that sieve and all of the larger
mesh sieves used.
volumetric flask, dilute to the mark with
writer, and mix thoroughly. Within 1 hour
4.4.5 Apparent density.
after preparation, transfer a portion of the
solution to a spectrophotometer cell and fill.
4.4.5.1 Apparatus.- The apparatus shall
the reference cell with water. Read the trans-
mittance (T) of the solution at a wave length
consist of a cylinder and a glass funnel. The
of 430 millimicrons.
cylinder shall have an internal length of 11
1 centimeters (cm.) and a volume of 100
ml. and may be made by cutting off a 250 ml.
graduate at the 100-ml. graduation, The glass
Note: The above procedure and formula ap-
funnel shall be approximately 9 cm. in
ply when: (1) the spectrophotometer cell
diameter at the top and shall have a stem
depth is 10 millimeters (mm.), (2) the trans-
approximately 2.5 cm. in length and 1.5 cm.
mittance (T) is expressed as a fraction less
in inside diameter.
than 1, and (3) the spectrophotometer is a
Hwdy-General Electric recording spectro-
4.4.5.2 Procedure. -- Weigh the cylinder.
photometer having an effective band width of
Support the funnel so that the end of the
10 millimicrons. When another instrument is
stem is centrally located 1 cm. above the top
used, it shall first be calibrated against a
of the cylinder, Dry, to a constant weight
Hardy-General Electric instrument or against
in an oven maintained at 70 to 75C., a por-
U. S. Bureau of Standards glare filters. When
tion of the specimen sufficient to fill the
a spectrophotometer cell of different depth
cylinder to overflowing. Shake the specimen.
is used, calculate the weight of the specimen
from a paper into the funnel at a rate of ap-
in inverse proportion.
proximately 60 ml. per minute. Avoid jarring
the cylinder during the filling operation. If
4.4.3 Moisture .--Determine the moisture
clogging occurs in the funnel, return the
content of the material in general accordance
contents to the paper and repeat the filling
with method No. 300.1.5 of Specification VV-
until the material overflows the cylinder.
L-791. Use a 50-gm. specimen of the ma-
Strike off the material level with the top of
terial, 600 ml. of toluene as the solvent, a
1,000-ml. flask, and an oil bath or electric
the cylinder and weigh the cylinder and the
contents. Calculate the apparent density of
heating mantle as a source of heat.
the specimen by dividing the increase in
weight of the cylinder by 100.
4.4.4 Particle Size.- Numbers 60, 100, and
200 U. S. standard sieves, conforming to
4.4.6 Performance. --Prepare and fire six
Specification RR-S-366, shall be selected for
yellow smoke grenades in accordance with
the test. Nest the sieves in order of decreas-
ing mesh size, placing the largest mesh on
Specification 96-111-92. Upon firing, the
top and a pan at the bottom, Weigh, to the
grenades thus prepared shall conform to 3.5
nearest centigram (cg.), approximately 10
(see 6.4 and 6.6).
gm. of the material and transfer to the No.
60 sieve. Brush the material with a camel's-
4.5 Rejection and resubmission. -If any
hair brush until no more material passes
specimen, selected as specified in 4.2, fails to
through the sieve. Remove the sieve and
conform to this specification, the lot shall be
weigh the material left on the sieve Repeat
rejected. The contractor, at no expense to
the procedure with the material on the No.
the Government shall have the option of
100 and No. 200 sieves. Calculate the per-
having a partial or complete Analysis made
3
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