NEW SENSOR MAKES LIFE SIMPLER FOR BAKERY MACHINERY MAKERS - AND
USERS
An additional option to the Series 2000 gauge roll offered by Sasib
Food & Beverage is a motorised roller gap adjustment which greatly
reduces the amount of fiddly adjustment needed to ensure a consistent
dough sheet thickness and which also permits the gap to be automatically
adjusted for different dough products.
Sasib Food and Beverage manufactures a wide range of baking
machines for producing food products from flat sheet dough such
as crisps and biscuits. During the continuous process, gauge
rollers form the dough into a flat sheet of the correct thickness
before the biscuit shapes are formed, cut out and baked. The
control of the thickness of the dough sheet is important for
the quality and standards of the finished product.
At the heart of this new refinement is the Positek
P103 Linear Inductive Position Sensor mounted at each set
of the paired gauge rolls. The sensor measures the gap between
the rolls and relays the information to the PLC. The adoption
of the Positek LIPS® sensor in preference
to the older LVDT sensors has saved the manufacturer both time and
money according to Geoff Speak, Electrical Manager for Sasib's Food
& Beverage Machinery Division, because the P103 comes ready-calibrated. The
sensor is now operating on a number of sites throughout the world.
The sensor has a flange mounting which provides a well-defined
reference face for mounting with two easily accessible mounting
holes. The sensor is supplied by Positek calibrated
to within ± 0.25% of the overall range both for the slope and
the offset of the output. The flange is used as the reference
when it is calibrated. When installing the sensor it requires
only mechanical adjustment by a Vernier screw incorporated into
the roller mechanism to take account of mechanical tolerances
in the mechanism; installation and commissioning is now a much
speedier and less complicated operation than it was in the days
of the LVDT sensors which needed careful and long winded electrical
calibration.
The internally-integrated Positek sensors permit further
simplification of the new Sasib gauge roll because the output
is a loop powered two-wire 4-20mA format. The older LVDT
sensors needed a special electronics module separated from the
sensor to convert the output to mA and to avoid the voltage drop
which would otherwise occur over the often considerable distances
between the sensor and the PLC. The old electronic module
needed to be wired up with the sensor with multiple connections.
The Positek sensor has just 2 connections to make resulting
in quicker installation.
A further advantage of the LIPS® sensor
derives from its fully linear response over the entire mechanical
range. The sensor provides a linear response to within ± 0.5%
of the travel. This means that not only is there no longer the
need to incorporate adjustments in the PLC to correct the non-linearity
of the LVDT response but also that the same sensor units can be used
for a much wider range of dough sheet thicknesses - and hence product
lines. As well as the good linearity, the Positek sensor
has a very short body length compared to the travel which helps to
save space in the application.
The P103 sensor is a standard sensor with a small special
modification requested by Sasib. It incorporates technology
developed by Positek and used in its other displacement sensor
products. This PIPS® technology is
based on inductive coils and uses a unique custom integrated circuit
to produce an accurate analogue output signal. Several versions
of the P103 sensor are supplied for different gauge roll travels
from 10mm up to 50mm.
For more information contact: Sales at Positek Limited
Tel: +44 (0)1242 820027 Fax: +44 ( 0)1242 820615