32
BA 21
Schaeffler Technologies
Top-Laser TRUMMY2
Measuring the strand force
Measuring procedure:
■
For a display in N, adjust the measuring device according to
Figure 2
. Before beginning measurement, enter the belt mass and
strand length according to
Figure 2
.
TRUMMY2 measures the natural frequency of the belt and
converts the result automatically into the tensioning force:
T
N
Strand force
m
kg/m
Linear belt mass
L
m
Length of the free belt strand
f
Hz
Measured natural frequency of the free belt.
Determine the strand force in the same way as the natural frequency
measurement according to page 30.
Measurement deviations
Measurement deviations up to
⫾
10% during multiple measure-
ments on the same drive belt are generally not the result of any
measurement error or equipment error. They are generally caused by
mechanical tolerances in the drive systems.
If, despite careful preparation, no measurement results are shown,
this may have the following causes:
Possible cause 1
The drive belt is vibrating below the measurement limit of 10 Hz:
■
Tension the belt, or for very long, open strand lengths support
the belt to shorten the strand length. Before measuring again,
enter the modified belt length.
Possible cause 2
Despite a correctly tensioned drive belt, no measured values or
only low measured values are displayed:
■
It may be that the light from the measurement sensor is not being
reflected adequately. To improve the reflection, stick a piece of
light-coloured adhesive tape to the belt, or moisten it slightly at
the measurement point.
■
Power supply:
9 V battery; if “Low Bat” appears in the display, the battery must
be changed.
■
Energy saving mode:
the device will switch itself off automatically if no measurements
are made for a period of 8 min.
Strand force
