Humboldt HM-2415 Soil Volume Change Meter (PVC) - Manual (Page 3)

Compaction of Sample
A.
Disassemble the Soil Volume Change Meter.
1. Remove crosshead (#11 Figure 1) and proving ring (#2) by loosening
hex nuts (#21) at top of each rod. The rods may remain screwed into
the base (#1 0) but place the crosshead and proving ring where it will
not be jarred during compaction.
2. Unscrew and put aside the lucite container (#18) . Leave O·ring (#22}
in place.
3. Remove compaction ring (#15) and spacer ring (#16) by unscrewing
the 3 bolts (#23) holding them to the base (#1 0).
4. Wipe equipment with clean cloth.
B. Assemble meter for compaction.
1. Fit compaction ring (#15--the thicker ring) on base (#1 0) and align
bolt holes with those in base.
2. Place spacer ring {#16) on compaction ring so the radial grooves are
at top and align bolt holes with those in base.
3. Insert the 3 bolts (#23} through both the rings and the base and
tighten firmly to base.
C. Place soil sample in ring assembly in 3 layers of equal amounts,
compacting each layer separately by use of the hammer.
1. Place 3 heaping teaspoonsful of sample in ring assembly and smooth
lightly with hammer to firm up the surface before applying the blows.
(This reduces the amount of soil "jumping" out of the mold during
compaction.)
2. Place apparatus on a solid level floor.
3. Position sleeve of hammer 1/8" (3 mm) from soil and hold firmly
against the inside of the spacer ring (#16). Be sure hammer sleeve
rests inside rings so that hammer does not damage them in falling.
Hold sleeve and hammer perpendicular and in line with supporting
rods (#12).
4. Raise hammer to top of sleeve and let it fall free (not striking sides
of sleeve). Space blows evenly over surface of sample by shifting
hammer after each blow.
5. Repeat the process described in steps 1 - 4 for each layer,
compacting the first two layers with 7 blows each. After compacting
both the first and second layers, scratch the top surface of the layer
with a knife to assure proper bond with the next layer.