This document describes an eddy-current displacement sensor system used to continuously measure the gap between rolls in a calender press. The system uses four eddy-current sensors mounted opposite each other to measure the distance from a fixed reference point to aluminum rings on the top and bottom rolls. The sum of the two distances is used to determine the roll gap. The eddy-current sensors were selected for this application because they can measure contactless, accurately, and reliably without needing maintenance in the oily measurement environment.

1. A080_e
Eddy-current displacement sensors
eddyNCDT
Special roll gap measurement on calender press
For continuous, uniform material processing in the Technical details
field of sealing technology, the gap between the - Measuring range: 6 mm
rolls must be set with the hydraulic adjustment - Accuracy: 5/10 mm
device and maintained constant. For this reason the - Resolution: 1/100 mm
top and bottom rolls are provided with a shoulder - Bandwidth: 100 Hz
and an aluminum ring as measurement objects to
the left and right. Using the aluminum ring, errors Ambient conditions
due to the roll material can be avoided. Two eddy - Temperature: appr. 40 °C
current sensors mounted opposite one another - Medium: air
measure the distance to the aluminum ring from a - Interference fields: none
fixed reference point. The roll gap can be found
from the sum of the two distances. Measurement system set-up
4 x U6 4 x C6/90
Reasons for the system selection 4 x BC - U6 - C6 1 x R 5584
The eddy-current displacement sensors measure 1 x DD 500 4 x DL 500
reliably, accurately and without physical contact. ! x FP 514 2 x FP 507
They are therefore free from wear and need no
maintenance. Dirt and oil in the measurement gap Principle
have no effect on the measurement result.
SPS roll 1
electronics
roll gap
alu ring roll 2
MICRO-EPSILON MESSTECHNIK GmbH & CO. KG A member of micro-epsilon group.
Königbacher Strasse 15 Tel.: 0 85 42/1 68-0 info@micro-epsilon.de Zertifiziert nach DIN EN ISO 9001 : 2000
94496 Ortenburg Fax: 0 85 42/1 68 90 www.micro-epsilon.de Änderungen vorbehalten / Y9781080