Measuring Strain; Tension And Compression On A Single Axis - Hioki MEMORY HiLOGGER LR8450 Instruction Manual

Measuring Strain

11.2 Measuring Strain

Tension and compression on a single axis

Gage method
1
1-gage method (2-wire)*
1
1-gage method (3-wire)*
2-gage method
(adjacent side)
(active dummy method)*
4-gage method
(perpendicular placement)
4-gage method
(active dummy method)
270
Bridge circuit diagram
Output
voltage
e
Applied voltage
E
Output
voltage
e
Applied voltage
E
Output
1 voltage
e
Applied voltage
E
Applied voltage
E
Output
e = ε
ε: Strain
e = 2(1 +
Poisson's ratio)
× ε
Output
voltage
e
e = 2ε
Remarks
This is the most typical
connection method.
This connection method cancels
the effects of temperature on
the strain gage wiring.
In this connection method,
a reference strain gage is
affixed to a specimen made
of the same material as the
measurement target that is
not being subjected to stress.
Apparent strain resulting
from temperature changes is
measured using the reference
gage and canceled out.
This connection method
cancels the effects of
temperature changes of the
measurement target. Use the
scaling conversion ratio slope
described below.
1 / {2 × (1 + Poisson's ratio)}
This connection method is
not affected by temperature
changes of the measurement
2
target or bending strain. *