21
Magtrol TM Series In-Line Torque Transducers
Chapter 2 – Installation / Configuration
2.3
measuring shaft vibrations
The presence of radial misalignment in the configuration will give rise to periodic radial displacement
of the torque measuring shaft. This, in turn, will induce parasitic vibrations influencing the torque
measuring signal.
x
x
Figure 2–4 Radial Displacement
2.3.1
p
erMITTed
V
IBraTIonS
on
M
eaSurIng
S
haFT
The periodic displacement of the measuring shaft generates vibrations. These vibrations express
themselves in either speed (in m/s) or acceleration (in m/s² or g).
Note:
"g" is normally used as a unit for acceleration. It represents the
Earth's acceleration of 9,81 m/s², often rounded up to 10 m/s².
both of these parameters depend on the radial displacement and the speed of the shaft. The formulas
used to calculate this speed and acceleration are as follows:
Speed:
v = 2 ·
π
·
n
·
x
[m/s]
Acceleration:
a = 4 ·
π
² ·
n
² ·
x
[m/s²]
"
x
" represents radial displacement, expressed in meters (see
Figure 2–4
)
"
n
" represents rotational speed, in s
-1
The vibratory acceleration of the above is illustrated with the graph in
Figure 2–5
.
