ABB PFVL142R-16MN Heavy-duty circular load cell

ABB PFVL142R-16MN Heavy-duty circular load cell

Pressductor® Technology

and the measurement principle

ABB’s Millmate Roll Force load cells are based on the well

known Pressductor® principle patented in 1954. the magneto

elastic effect, according to which the magnetic properties of

steel are influenced by mechanical forces acting on it.

In the transducer body there are four holes. Two coils at

right angles to each other are wound through these holes.

One winding (the primary) is supplied with an alternating

current; the other winding (the secondary) acts as a measure

ment winding. Since the two windings are at right angles to

each other, there is no magnetic coupling between them as

long as there is no load on the transducer body.

If the transducer body is loaded (as shown in the figure), the

ield pattern changes. The permeability of the steel is reduced in

the direction of the force and increases in the direction at right

angles. The result is a change in the symmetry of the magnetic flux,

so that some of the flux induces a voltage in the secondary wind

ing. The induced voltage is proportional to the load.

The measurement principle is based on the magneto elastic effect, ac

cording to which the magnetic properties of a material are influenced

by mechanical stress. The transducer is magnetized via the primary

coil. A voltage proportional to the applied force is induced in the

secondary coil.

Right from the beginning of the Pressductor era a trans

ducer based on this measurement principle turned out to

be perfect for the rolling mill environment.

The key factors are:

•    No    compression    of    the    transducer    is    needed    to    achieve    a    reliable

signal corresponding to the applied force.

•    An    overload    capacity    of    up    to    700%    is    achieved    by    utilizing    only    a

small part of the elasticity of steel.

•    The    standard    load    cell    consists    of    1.500    transducers,

always ensuring a true roll force measurement, even if the

load is unevenly distributed.

•    Signal-to-noise    level    is    outstanding    due    to    the    high    signal    output

from the transducer (500 mV).

The rock-solid design of the Pressductor load cells fulfils

these key factors and will assure you many years of accurate

measurements in your rolling mill

ABB’s force measurement systems in

rolling mills

Your selection of load cells, control units and options

ABB’s Roll Force Systems offer a comprehensive selection of

load cells, control units and options covering your needs for

accurate and reliable roll force measurement in your rolling

mill.

You choose from the Millmate Roll Force load cells coming

in three different versions: Circular, Rectangular and Annular.

The most common installation application for the circular ver

sion is under the mill screw. The rectangular version is normal

ly installed under the lower back-up roll bearing. The annular

version is installed between the mill nut and the mill stand.

The choice of control unit is made in the light of system require

ments and according to your communication needs.

The heavy-duty Millmate Roll Force load cells have high-stability components encased in a protective stainless steel box provid ing the built-in calibration and temperature compensation of the load cell.

Due to its low impedance and high output signal power the Millmate Roll Force load cell has an extremely low sensitivity to insulation defects and maintains its measuring accuracy down to a 10 kΩ insulation level.

The load cell output signal is calibrated for full interchangeability between load cells of the same type and size.

The various types and the wide load range cover practically all conceivable roll force measurement applications