Half-Bridge Type I; Figure 2-7. Half-Bridge Type I Measuring Axial And Bending Strain - National Instruments SC Express NI PXIe-4339 User Manual

Chapter 2 Using the Module
To convert module readings to strain use the following equation:

Half-Bridge Type I

This section provides information for the half-bridge strain-gage configuration type I. The
half-bridge type I measures either axial or bending strain. Figure 2-7 shows how to position
strain-gage resistors in an axial and bending configurations. Figure 2-8 shows the half-bridge
type I circuit wiring diagram.

Figure 2-7. Half-Bridge Type I Measuring Axial and Bending Strain

A half-bridge type I has the following characteristics:
• Two active strain-gage elements. One strain-gage element is mounted in the direction of
axial strain while the other acts as a Poisson gage and is mounted perpendicular to the
principal axis of strain.
• Half-bridge completion resistors (R
• Sensitive to both axial and bending strain.
• Sensitivity ~ 0.65 µV/V per µε, for GF = 2.0.
2-8 | ni.com
strain   
R (+ )
4
Axial
R (– )
3
and R
1
4V
–
r
= ------------------------------- -
 
GF 1 2V
+
r
R
4
(– )
R
3
) are provided by the NI PXIe-4339.
2
(+ )
Bending