Geokon 4370, Инструкция по эксплуатации, Страница: 15 / 19

The
polynomial
equation is as follows:
Concrete Stress (S) = AR
1
2 + BR
1
+ C
Equation 2 - Digits to Concrete Stress (Polynomial Equation)
Where;
R
1
is the is the current reading
A and B are the polynomial gauge factors , in MPa/digit or psi/digit taken from the calibration
report.
C is calculated using the equation:
S = AR
1
2 + BR
1
Equation 3 - Polynomial gauge Factor C
Where;
S = 0
R
1
is the
initial field zero reading
A and B are the
polynomial gauge factors
, in MPa/digit or psi/digit taken from the calibration
report.
For example:
If;
A = -6.568E-07 MPa/digit
B = -0.009799 MPa/digit
Initial field zero reading = 7035 digits
Current reading = 5219 digits
Then;
C = -6.568E-07*7035^2 - 0.009799*7035 = 101.44
And the calculated concrete stress using =
S = 6.658E-07*5219^2 - 0.009799*5219+101.44 = 32.41 MPa
Compare these values to the actual applied stress of 32.47MPa
6.2. Temperature Correction
The Model 4370 Concrete Stressmeter has a coefficient of thermal expansion very similar to the
concrete surrounding it so in most cases correction is not necessary.