CEMB USA C72 (B) - Manual (Page 20)

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Fig.20
Fig. A Fig. B
GB
5.5 ECCENTRICTY MEASUREMENT (OPTION)
The fi gures are signifi cantly enlarged to highlight the external surface of the tyre and the wheel rotation axis.
Fig. A highlights the total Peak-Peak eccentricity measurement, defi ned as the maximum radial offset
of the surface of the tyre.
Fig. B highlights the 1st harmonic eccentricity
measurement, i.e. the eccentricity of the rim
“refl ecting” the shape of the tyre, to calculate
the averages values of local offset of the tyre
from roundness.
It is evident that the P-P measurement is
normally higher than the 1st harmonic
measurement. Tyre manufacturers usually
provide two different tolerances for the two
types of eccentricity.
At the end of a balancing spin, eccentricity measurement of the tyre can be performed automatically
using the SONAR sensor placed on the guard. To enable measurement at the end of every spin, see
the section
MENU FUNCTION CONTROL .
The value of the fi rst harmonic with the relative phase
is displayed.
Hold down the button to display the Peak-Peak
value.
Release the button to return to the display of the
fi rst harmonic value.
BACK TO MEASUREMENT WINDOW
N.B.: The eccentricity measurement is valid up to max. tyre Ø of 1000 mm.