Load Cells Pfcl 201; Principle Of Measurement - ABB PFCL 201 User Manual

Pressductor PillowBlock Load Cells, Vertical Measuring PFCL 201, User Manual
1 Introduction
1.3.2
1.3.3
3BSE023881R0101 en Rev H
Load cell cabling
Control unit
Junction box
Figure 1. Complete Measuring System

Load Cells PFCL 201

The load cells are installed under the roll bearings, where they measure forces at right angles to the
mounting surface.
The reactive force from the strip, which is proportional to the strip tension, is transferred to the load
cells via the roll and the bearings.
The load cells are connected to the control unit via a junction box. The control unit converts the
load cell signals to DC voltages that are proportional to the reaction force. Depending on which
control unit is chosen, it is possible to have the analog signals for the two individual load cells (A
and B), the sum of the load cell signals (A+B), and/or the difference between the load cell signals
(A-B).

Principle of Measurement

The load cell only measures force in the direction F
negative. The load cell is normally installed under the roll bearings. When there is a strip in tension
over the roll, the tension (T) gives rise to two force components, one in the direction of measure-
ment of the load cell (F ) and one at right angles (F
R
The measuring force depends on the relationship between the tension (T) and the wrap angle
formed by the strip around the measuring roll.
Load cells
Adapter plates
Output signals
A
INDIVIDUELL A
Sum A+B
SUMMATION A+B
Differential A-B
DIFFERENS A-B
INDIVIDUELL B
B
. The measurement force may be positive or
R
).
V
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