Geokon 4911, Installation Manual, Page: 26 / 27

20
By making the various substitutions of Table 6 the relationship between strain in the unbonded
section versus change in readout digits can be obtained.
Using the #6 rebar as an example, with English conventions, yields the following:
6 10
5 . 7
442 . 0 30
5 . 0
390 . 0 30
5
2 359 . 0
− ×


















×
+
×
+ ×
× ∆ =
F
R
t
ε
( )
( )
6 10 06205 . 0 0957 . 0 − × + ∆ = F R
t
ε
Doing these calculations for the other sizes of rebar yields the data shown in Table 7. Use Table
7 to obtain the microstrain/digit gauge factor (C) from the lbs. or kg. per digit gauge factor (F).
Rebar Size Conversion Formula - English Conversion Formula - Metric
#4 C = 0.0957 + F x 0.12220 C = 0.0957 + F x 0.2707
#5 C = 0.0957 + F x 0.07888 C = 0.0957 + F x 0.2091
#6 C = 0.0957 + F x 0.06205 C = 0.0957 + F x 0.1373
#7 C = 0.0957 + F x 0.04416 C = 0.0957 + F x 0.0977
#8 C = 0.0957 + F x 0.03310 C = 0.0957 + F x 0.0733
#9 C = 0.0957 + F x 0.02584 C = 0.0957 + F x 0.0572
#10 C = 0.0957 + F x 0.02073 C = 0.0957 + F x 0.0459
#11 C = 0.0957 + F x 0.01700 C = 0.0957 + F x 0.0377
#12 C = 0.0957 + F x 0.01422 C = 0.0957 + F x 0.0315
#14 C = 0.0957 + F x 0.01037 C = 0.0957 + F x 0.0230
Table 7 - Microstrain Conversion Factors