Roland udk20 Manual page 26

System description
3.4.2 Program parameters
The sensor is operated in two different modes.
For FE material an electro magnetical method – called "P" measurement – is used. For the P
measurement a compensation curve for linearization exists. The compensation curve fits to ST37
steel. Other steel alloys resp. magnetical materials deviate from this curve. This causes measuring
results which can deviate for more than 5% from the real sheet thickness. In such cases it is useful
to calibrate the unit (later merely called "Teach-In").
For NF material an eddy current method – called "W" measurement – is applied. Here a Teach-In is
required, since there is no general linearization curve.
In order to avoid frequent Teach-In procedures for different materials and thicknesses, the unit
provides for 255 program memories. Every such memory consists of a data set with the following
parameters.
"Sensor number"
For multi-channel systems (e.g. UDK20-2PW...) or a system with external sensor switch box SSB-
UDK10 the selected sensor must be entered.
"Material"
Selects the material type FE, NF or LM (slightly magnetical stainless steels). In case of unknown
material AUTO must be chosen. For all settings (except for FE) a Teach-In is required.
"Nominal measure"
Changes the nominal measure. It can be shown in mm or inch.
Default setting either 0,03mm or 0,001 inch.
"TO" and "TU"
Changes the limit values for the lower and upper switching threshold. The values can be entered
either in % or in mm/inch. On these thresholds the status signals depend. In a window comparator
the three signals will be generated from the measuring signal.
The signal "0-sheet" is generated when the measuring signal falls short of the lower switching
threshold. The lower switching threshold TU can be set from 1...99%. The signal "2-sheet" is
generated when the upper switching threshold is exceeded. The upper switching threshold TO can
be set from 100...150%. If the measuring value is within both limits, the signal "1-sheet" is
generated.
O bere Schaltschwelle
Upper switching threshold
Untere Schaltschwelle
Lower switching threshold
Fig. 5: Visualisation of switching thresholds
26
ROLAND ELECTRONIC GmbH · Otto-Maurer-Str. 17 · DE 75210 Keltern · Phone +49 (0)7236-9392-0 · Fax +49 (0)7236-9392-33
Double Sheet Detector R1000 series UDK20
2
TO
1
Signal
TU
0
Manual
c
a Signal range for 0-sheet
b Signal range for 1-sheet
b
c Signal range for 2-sheet
TO switching threshold for upper limit
a
TU switching threshold for lower limit
B0048991 / Rev. 1.3