Humboldt H-4340 Sand Equivalent Test Set with Case - Manual (Page 6)

NOTE 4: Experiments show that as the amount of material being reduced by splitting
or quartering is decreased, the accuracy of providing representative portions is
decreased. For this reason, it is imperative that extreme care be exercised when
preparing the test specimens.
1. Split or quarter enough material to fill four tin measures to the brim or slightly
rounded above the brim in the following manner:
A. If it appears necessary, dampen the material to avoid segregation of loss of
fines during the splitting or quartering operations. Use care in adding moisture
to the sample to retain a free flowing condition of the material.
B. Using the measuring tin, dip out four of these measures from the sample. Each
time a measure full of the material is dipped from the sample, tap the bottom
edge of the measure on a work table or other hard surface at least four times
and jog it slightly to produce a measure of consolidated material level-full or
slightly rounded above the brim.
C. Determine and record the amount of material contained in these four measures
either by weight or by volume in a dry plastic cylinder.
D. Return this material back to the sample and proceed to split or quarter the
material making the necessary adjustments to obtain this predetermined weight
or volume. When this weight or volume is obtained, two successive splitting or
quartering operations without adjustment should provide the proper amount of
material to fill the measure.
E. Dry each test specimen to constant weight at 230 ± 9° F (105 ± 5° C) and cool
to room temperature before testing.
NOTE 5: Sand equivalent results on test specimens that have not been dried will
generally be lower than the results obtained on identical test specimens that have been
dried. As a time-saving expedient, it is permissible to test most materials without drying
when the sand equivalent value is used to determine compliance with a specification
giving a minimum acceptable test value. If the resulting test value is lower than that
specified, however, it will be necessary to rerun the test on a dried test specimen. If
the sand equivalent, determined from a test on one dried test specimen, is below
minimum specification limit, it will be necessary to perform two additional tests on
dried test specimens from the same sample. The sand equivalent for a sample shall be
determined in accordance with the section on calculations.
2. Prepare the desired number of test specimens from the sample as follows:
A. Maintaining a free-flowing condition, dampen the material sufficiently to
prevent segregation or loss of fines.
B. Split or quarter out 1000 to 1500 g of the material. Mix thoroughly with a hand
trowel in a circular pan by scooping toward the middle of the pan while rotating
it horizontally. Mixing or remixing should be continued for at least 1 min to
achieve uniformity. Check the material for the necessary moisture condition by
tightly squeezing a small portion of the thoroughly mixed sample in the palm of
the hand.