Manual
Weld Seam Detection System R4000 SND40
for Tubes, Cans and Drums
B0059001 / Rev. 2.3
System description
ROLAND ELECTRONIC GmbH · Otto-Maurer-Str. 17 · DE 75210 Keltern · Phone +49 (0)7236-9392-0 · Fax +49 (0)7236-9392-33
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2.5.1 Notes for placement of the SND40 components
The control unit SND40 is to be installed so that the control and monitoring of the unit is possible
under the following conditions:
•
easily accessible in accordance with ergonomic principles in all operating modes, especially in
normal operation
•
ideally, with a view to the sensor, so that the positioning process can be observed
•
the back side of the device must be accessible to get access to connections and assemblies
•
the ventilation holes must not be obstructed
•
The operation and monitoring is required:
•
during commissioning, maintenance and service work
•
when new types of tubes have to be set up
•
at optimization work regarding reliability of detection
•
for occasional assessment of the process, for example via the statistics function
•
at occurring faults
Regarding the placement of the sensors to the instructions in chapter 2.4.3 "Placement device for
the sensor" are to be considered. In addition, the following points are recommended:
•
mounting the sensor from above
•
the sensor should be accessible for maintenance
•
attach a note that the sensor is working with magnetic fields
Safety advice!
Persons with pacemakers are not permitted to work on the sensor.
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2.6
Details of the dB-value
For determining the signal-to-noise ratio the SND40 automatically calculates and displays the
dB-value of the signal to noise ratio.
The level of the weld seam signal always serves as reference for the signal level. The value is used
to control the automatic sorting out process.
Note: For the SND40 the weld seam always is at the maximum appearing in the signal of a tube
turn. In the following example the weld seam level (and thus the signal level) 0.47 V.
In direct vicinity of the weld seam there might be similar strong signals – e.g. the flanks of the weld
seam signal. This effect is based on the fact that the weld seam is not infinitely delicate, but has a
noticeable size. This is why the signal from one complete turn of a tube is divided into two zones,
the zone in immediate proximity to the weld and the rest outside of the weld zone.
For further locating the noise level the weld seam zone becomes suppressed. For doing so, a
circumferential area symmetrically left and right of the weld seam is defined, which each has the
width of the parameter “
weld seam width
“. The weld seam width (1…20%) can be individually set
for every program.
Thus the remaining circumferential area is considered for determining the noise level.
