Operating Manual EMGZ421
14
Mathematical method
If the material tension cannot be simulated, calibration has to be done by calculation. This
way of calibrating is less accurate because the exact angles are often unknown and the
effective mounting conditions, which usually deviate from the ideal, are not taken into
account.
•
Offset adjustment has to be done as described under „Simulating method“.
•
The Gain value will be calculated by the following formula and then inputted in the
parameters
gain channel A / gain channel B
(refer to „10. Parametrization“).
fig. 11: 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
material wrap angle
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
δ
Angle between measuring web axis and F
M
(
)
2
2
/
sin
sin
1
⋅
⋅
=
=
γ
δ
ckB
GainFeedba
ckA
GainFeedba
