Operating Manual EMGZ480
17
8.2
Mathematical Method
If the material tension cannot be simulated with weights as described in paragraph 8.1,
the calibration has to be done by calculation. This way of calibrating is less accurate
because the exact angles are often unknown. The actual mounting conditions, which
usually deviate from the ideal world, can also not be taken into account.
Mathematical base for calculating the Gain factor:
fig. 13: Force vectors in the FMS force measuring bearing
C431012e
Definition of symbols:
α
angle between vertical and
measuring web axis
F
B
material
tension
β
angle between vertical and F
M
F
G
roller
weight
γ
wrap angle of material
F
M
measuring force resulting from F
B
γ
1
entry angle of material
F
Meff
effective measuring force
γ
2
exit angle of material
n
number of force sensors
δ
Angle between measuring web axis
and F
M
(
)
n
GainFactor
⋅
⋅
=
2
/
sin
sin
1
γ
δ