Magtrol TM 301, Руководство пользователя

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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.
Fig.2-5 Radial displacement
2.3.1 PERMITTED VIBRATIONS ON MEASURING SHAFT
The periodic displacement of the measuring shaft generates vibrations. These vibrations express them-
selves in either speed (in m/s) or acceleration (in m/s² or g)
. «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:
The vibratory acceleration of the above is illustrated with the following graph (
see Fig.2-6
)
X
X
NOTICE
Speed : v = 2 · π · n · x [m/s]
Acceleration : a = 4 · π² · n² · x [m/s²]
"x" represents radial displacement, expressed in meters (
see Fig.2-5
)
"n" represents rotational speed, in s
-1
17
TM
series
INSTALLATION / CONFIGURATION