Humboldt HM-2415 Soil Volume Change Meter (PVC) - Manual (Page 9)

Proving Ring
Reading
Swell Index
(#/SF)
PVC
Category
Plasticity
Index (%)
5 775 0.8 8.5
6 925 1.0 9.5
7 1075 1.2 10.7
8 1250 1.4 11.7
9 1375 1.4 12.7
10 1550 1.8 13.8
10.8 1675 2.0 14.6
11 1700 2.0 14.8
12 1875 2.2 15.8
13 2025 2.4 17.0
14 2175 2.65 18.0
15 2350 2.85 19.0
16 2500 3.05 20.0
17 2675 3.3 21.5
18 2800 3.45 22.5
19 2975 3.7 23.8
20 3150 3.9 25.0
20.3 3200 4.0 25.5
21 3300 4.1 26.0
22 3450 4.3 27.5
23 3600 4.5 28.5
24 3775 4.75 29.8
25 3925 4.95 30.8
26 4075 5.15 31.8
27 4225 5.4 33.0
28 4375 5.55 34.0
29 4525 5.75 35.3
30 4700 5.95 37.0
30.2 4725 6.00 37.1
31 4850 6.2 38.0
32 4975 6.35 39.0
33 5125 6.5 40.4
34 5275 6.7 41.7
35 5425 6.9 43.4
36 5575 7.1 44.2
37 5725 7.25 45.5
38 5850 7.4 46.6
39 6000 7.5 48.0
40 6150 7.65 49.5
40.5 6225 7.7 50.0
Figure 5 - Conversion Table
TABLE FOR CONVERTING PROVING RING READINGS TO
PVC CATEGORY AND APPROXIMATE PLASTICITY INDEX
Prepared by the Architectural Section, Federal Housing Administration
Insuring Office, San Antonio, Texas