CGEO INTERNATIONAL LIMITED CGEO-CR, Installation Manual

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10
Temperature
：
20
℃
Humidity
：
32%RH
Testing Result
Range
：
(0---50)mm
Reader box: CGEO-PR-VW
Applied
Gage
Reading
1st Cycle
Gage
Reading
2nd Cycle
Gage
Reading
3rd Cycle
Average
Gage
Reading
Error Error
Displacement Linear Polynomial
(mm) (F.S) (F.S)
0.0 2441.8 2440.6 2441.5 2441.3
-0.20% -0.01%
10.0 3479.3 3479.7 3479.0 3479.3
0.06% 0.02%
20.0 4509.8 4508.1 4509.5 4509.1
0.16% 0.01%
30.0 5533.0 5532.3 5532.7 5532.7
0.13% -0.02%
40.0 6552.0 6551.7 6551.9 6551.9
0.03% -0.01%
50.0 7566.4 7566.3 7566.1 7566.3
-0.18% 0.01%
/ / / / /
/ /
Calculated Displacement:
Linear
，
L(mm) = G (R
1
-R
0
) + K (T
1
-T
0
)
Polynomial
，
L(mm) = AR
1
2
+ BR
1
+ C + K (T
1
-T
0
)
Linear Gage Factor
：
G = 0.00975839 mm/Digit
(mm) Polynomial Gage Factors
：
A = 0.000000026645441378193
B = 0.0094917094213891
C = -23.33732890100
Thermal Factor
：
K = 0.00853859 mm/
℃
R
0
……….Original Reading
T
0
……….Original Tempera
Hereinafter Blank
Figure 8 - Typical Crackmeter Calibration Sheet
4.2. Temperature Correction
The Model CGEO-CR Vibrating Wire Crackmeters have a very small coefficient of thermal
expansion so in many cases correction is not necessary. However, if maximum accuracy is desired
or the temperature changes are extreme (>10° C) corrections may be applied. The temperature
coefficient of the mass or member to which the Crackmeter is attached should also be taken into
account. By correcting the transducer for temperature changes the temperature coefficient of the
mass or member may be distinguished. The following equation applies;
D
corrected
= (R
1
- R
0
)

G + ((T
1
- T
0
)

K