Humboldt HM-2415 Soil Volume Change Meter (PVC) - Manual (Page 6)

B. To obtain a more exact PVC category and plasticity index, refer to the
tables prepared for your specifically calibrated unit. These tables (in
pounds, kilograms, and newtons) are separately supplied with this manual.
1. To calculate the equivalent swell index value in pounds per square
foot, take the reading from the proving ring dial and subtract the one
division that registered on the dial prior to swell.
2. Use this number on the proving ring calibration table to find the load
in pounds.
3. Calculate the equivalent swell index value in pounds per square foot
by dividing the toad (in pounds) by the area of the specimen (.04164
SQ. ft.}.
Example:
Proving ring dial indicator reading less .0001" (1 div.) = 58
Corresponding load from proving ring calibration table = 200 lb.
(This reading is for a fictitious proving ring .}
Swell index value in lb./sq. ft. = 200 = 4803 lb./sq. ft .
. 04164
4. Use the swell index values calculated as above in pounds/square foot
on the graphs in Figure 3, figure 4, and Figure 5 for determining the
PVC category and plasticity of the soil.
Specifications
Mold Assembly: Includes porous stones and loading cap
Proving Ring: 1,000 lb. (4.5 kN) capacity; dial indicator
Other Components: Loading pistons; compaction hammer
Specimen Ring: 2-3/4" (70 mm) diam.
Sample Size: 10 teaspoons
Water Required: 5 oz.
Charts: Convert readings to lbs./sq. ft. and then to PVC
(Potential Volume Change) rating
Dimensions: 7-1/4" diam. base x 15-1/2" h. (184 x 394 mm)
Weight: Net 25 lbs. (11.3 kg)