PRÜFTECHNIK EDDYSENSOR User manual

Operating manual
EDDYSENSOR
Doc. no. LAB 5329 Release 26.8.97 Release 4

EDDYCHEK®isaregisteredtrademarkofPRÜFTECHNIK
AG. The information contained in this leaflet is subject to
change without further notice due to the PRÜFTECHNIK
policy of continuous product development.
© 1997 PRÜFTECHNIK AG. No copying of this informa-
tion, in any form whatsoever, may be undertaken without
express written permission of PRÜFTECHNIK.
PRÜFTECHNIK NDT GmbH
Fischerfleck 8
D-85737 Ismaning, Germany
Telephone: [phone]
Telefax: +49 (0) 89/96 79 90
eMail: [email protected]

i
EDDYSENSOR Operating Manual
EDDYSENSOR Operating Manual
Contents Page
Safety instructions iv - vi
System diagram 1
Backplate connections of the EDDYSENSOR 2
1030 Front End Unit 3
Front module 3
Setting the gain 3
LED monitoring function 3
Filtering 4
Filter setting 4
F3 filter 4
F1 and F2 filters 5
Filter-to-speed relationship for filters F1 and F2 5
Graph of the F1 and F2 filter settings for normal applications 6
Graph of the F1 and F2 filter settings for slow applications 7
Graph of the F1 and F2 filter settings for fast applications 8
Back module 9
Connection of display device 9
Digital I/O 9
Test signal suppression 9
Connection of PLC or similar 10
Example of use 10
1031 Front End Unit 11
Front module 11
Setting the gain 11
LED monitoring function 11
Functions of the Gain switch 12
Summary of the displays 12
Manual gain setting 12
Filtering 13
Filter settings for F1 and F2 13
High pass filter settings for F1 and F2 14
Low pass filter settings for F1 and F2 14
Filter settings for F3 15
How to establish the filter settings 15
Filter settings for FI 1031 F1 and F2 16

ii EDDYSENSOR Operating Manual
1031 Back module 17
Connection of display device 17
Digital I/O 17
Test signal suppression 17
Connection of PLC or similar 18
Example of use 18
Delay unit 19
Front module 19
Switch settings 20
Front module -upper PCB 20
Delay 20
Duration 20
Prescaler 21
Activating the outputs 21
Line mode 22
Back module 22
PCB (showing modification status d) 22
System error (from modification status e onwards) 22
Encoder switch up to modification status d 22
Encoder switch from modification status e onwards 22
Encoder socket pin assignment 23
Output sockets 24
Fuses up to modification status d 25
Fuses from modification status e onwards 25
Changing a fuse 25
LAB 1110 connection box 26
Power unit 27
Function 27
Front module 27
Fuses for mains and operating voltages 27
Changing fuses 28
Back module 28
Example: WICU line with encoder 29-31

iii
EDDYSENSOR Operating Manual
Pin allocation of the I/O sockets 32
Analog signal output socket 32
Digital signal output socket 32
Encoder socket on DI1050BA 32
Potential-free output socket 33
Examples of connections using Digital I/O socket output 3434
3434
34
Alarm unit via a PLC 34
Alarm unit via a time-lag relay 34
Alarm unit via a time-lag relay using the internal current supply 34
Locating and changing fuses 35
Delay unit 35
PCB of the back module 35
Fuses up to modification status d 35
Fuses from modification status e onwards 35
Replacing the fuses 35
Power unit 36
Fuses 36
PCB of the front module 36
Replacing the fuses 36
Appendix - Filter tables 37
Technical data

iv EDDYSENSOR Operating Manual
General information
Due to the nature of eddycurrent testing, strong
electro-magnetic fields could affect the test results.
Areas of use This equipment is intended for use exclusively in collecting
and processing eddycurrent test data in areas where there
is no danger of explosion.
Electro-magnetic
compatibility
This equipment was tested for electro-magnetic compatibil-
ity according to EN 55011 Group 1, Class A and EN 50082-
2.
Operative restrictions Using this equipment in a residential area can lead to electro-
magnetic interference and therefore requires special authori-
zation from the national regulatory agency for post and tel-
ecommunications (BAPT).
Installation site
requirements
Installation instructions
•Temperature range: see "Technical Data"
•Flat, level installation surface
•Equipment must be far enough away from the wall to open
the rear door easily and access the interior
(For actual dimensions, see "Technical Data" at the back of
the operating manual.)
Technical data
The technical data relevant to this equipment is listed at the
back of the Operating Manual.

v
EDDYSENSOR Operating Manual
Safety information
ESD instructions
•Ensure that the power is off and disconnected from the
equipment (pull out the plug) before opening it
• Do not use the equipment with the housing open
•Repair work must only be carried out by authorized
specialists
•Use only original spare parts and accessories
•Only trained personnel may carry out service and
maintenance
•Any modification carried out without the agreement of the
manufacturer invalidates the guarantee
Safety instructions

vi EDDYSENSOR Operating Manual
Exchanging the plug-in modules

1
EDDYSENSOR Operating Manual
The EDDYSENSOR is a simple eddycurrent detection
device which senses the presence of a defect to
activate subsequent activities, e.g. shutting off the
cooling water in a welding line with annealing. The
minimum configuration consists of two units in a table-
top housing. A third unit is optional.
The minimum configuration is made up of the Front
End Unit in the left-hand position and the Power Unit in
the right-hand position. For safety reasons, the back
module of the Power Unit is supplied immovably as-
sembled in the table-top housing, LAB 1004. The op-
tional unit is the Delay Unit in the middle position. The
modules and their positions are shown in the diagram
above.
EDDYSENSOR System Diagram
Output signal
to peripherals
Input signal from test coil
Front End Unit
Front module
FM103xF
Optional
Power Unit
Delay Unit
Back module
FI103xBAfff
Front module
DM1050F
Back module
DI1050BA
Front module
PM1040F
Back module
PI1040BA

2EDDYSENSOR Operating Manual
The diagram shows the backplate of the EDDYSENSOR. The inputs and outputs are also shown. The output
signal for the configuration without the Delay Unit is taken from the backplate of the Front End Unit whereas for
the configuration with the Delay Unit, the delayed output signal is taken from the potential-free output on the
backplate of the Delay Unit.
EDDYSENSOR with Delay Unit
Backplate connections of the EDDYSENSOR
IMPORTANT
Whenever a module is removed or inserted
ensure that the power is OFF and the mains plug pulled OUT.
Also, the ESD instructions given on the separate sheet
at the front of this handbook must be observed
when any work is carried out on the equipment.
Voltage switch
between 115V/230V
Socket for
power supply
Delayed and undelayed
signal outputs for the
configuration with the
Delay Unit
Analog signal to
display the defect,
e.g. on a recorder, bar
graph or oscillo-
scope
Defect output of an
undelayed digital
signal for switching
peripherals such as
PLC, warning units,
etc.
Input signal from the
line encoder Coil

3
EDDYSENSOR Operating Manual
Front End Unit Back moduleFront module
The Front End Unit receives the signal from the coil inspecting the test
piece.
The bar graph display shows the amplitude of the signal from the coil. The
defectthresholdvalueis fixedat 50%of thefull bargraph display.Any signal
above this level (shown by red LEDs) is considered a defect signal and any
signal below the level (shown by green LEDs) is not.
These three LEDs
monitor defects, coil
defects and overload
The bar graph display
shows the amplitude of
the signal from the coil.
The defect threshold
level is fixed at 50%.
The amplitude below the
threshold level is
indicated by green LEDs
and above it by red
LEDs.
Front Module
Gain display
Rocker switch to set
the gain between 0
and 55 dBs
Set the gain required for the signal on the display on the front panel of the
unit to between 0 and 55 dBs using the +/– rocker switch. Set the gain high
enough so that the smallest detectable defect reaches approx. 60% on the
bar graph display but low enough to prevent noise interfering with the test
results.
There are three LEDs which indicate:
• defects, i.e. when the signal from the coil exceeds 50% of the bar
graph display
• coil defects such as a broken coil connection, continuous error
• any overload conditions, e.g. when the gain is set too high.
Setting the gain
LED monitoring function
EDDYSENSOR from above
FM1030F
Front
Back
Gain [dB]
Gain
FM 1.030F
Defect
Coil error
Overload
+
-
100
50
0%
F3

4EDDYSENSOR Operating Manual
Filtering There are three filters available for the EDDYSENSOR. The application
dictates which filter is required.
The F1 and F2 filters for this module consist of a variable low pass and high
passfilter whichcombine toprovide variableband pass filters.Because the
coils and their sensing widths are known we can calculate the filter range
in speed as this is more appropriate in practice than Hz. The filters can be
set very close to the testing speed – however, defects which occur outside
thisspeed range aredamped or suppressed.In applications where thetest
piece is brought up to its final speed over a longer time period, the filter has
to be set relatively wide in order not to damp or suppress signals which
occur in the acceleration phase.
F3 is a fixed bandwidth filter that can be switched between the two speed
ranges, 1 - 60 m/min and 30 - 1000 m/min.
The filters are selected by turning the hex switches on the printed circuit
board of the front module (see diagrams below and on next page).
The only switch active for filter F3 is HPL as shown in the diagram below.
There are two positions of HPL that can be selected according to the line
speed:
HPL = 0 for the speed range 1 - 60 m/min
HPL = 1 for the speed range 30 - 1000 m/min.
Filter setting
F3 filter
PCB
Side view of the printed
circuit board (PCB)
Front panel
These switches are not
used for the F3 filter
For 1 - 60 m/min, set HPL=0
For 30 - 1000 m/min, set HPL=1

5
EDDYSENSOR Operating Manual
F1 and F2 filters
The frequencies given for the high pass and low pass filters in the filter
tables in the appendix correspond to the speed ranges shown on the right.
Theswitch settingsrequired canbe coarselyset byusing thegraphs shown
onthe followingpages tomatch theline speedrange whereHPH/HPL is the
lower limit and LPH/LPL the upper limit. The precise settings required can
be found in the tables included in the appendix.
Ideally, the filter settings should be established using a test piece prepared
with standard defects and a test bench. The settings should be made so
that any interference signals are suppressed while the defect signal itself
remainsundistorted. For optimum results the band pass should be as wide
as possible but as narrow as necessary.
To give a reasonable bandwidth we recommend:
VLine / 4: Switch setting HPH/HPL
VLine x 2: Switch setting LPH/LPL
Filter-to-speed relationship for
filters F1 and F2
PCB
Front panel
Side view of the printed
circuit board (PCB)
LPH HPH
HPL
Low pass filter
e.g.for a setting of 17,
LPH=1 LPL=7
High pass filter
e.g.for a setting of 20,
HPH=2 HPL=0
LPL
For both of these filters there are two pairs of switches, one pair for the low
pass filter (LPH/LPL) and one pair for the high pass filter (HPH/HPL) shown
in the diagram below. The two settings together form the required band
pass filter. The settings are given in the graphs following and in the table
included at the end of the document.

6EDDYSENSOR Operating Manual
Graph of the F1 and F2 filter settings for slow applications
(Speed range 0 - 300 m/min)

7
EDDYSENSOR Operating Manual
Graph of the F1 and F2 filter settings for normal applications
(Speed range 20 -1800 m/min)

8EDDYSENSOR Operating Manual
Graph of the F1 and F2 filter settings for fast applications
(Speed range 150 - 8000 m/min)

9
EDDYSENSOR Operating Manual
Back Module
Front
FI1030BA
EDDYSENSOR from above
Back
The back module of this unit FIFI
FIFI
FI 1030BA1030BA
1030BA1030BA
1030BA provides a coil connection and
outputs for the analogue defect signal and for the digital defect level. This
unit is supplied in a number of frequency versions:
5 - 10 - 20 - 50 - 100 - 250 kHz.
Coil
FI 1.030BA
Digital
I/O
Analog Signal
0-10V
Output for the defect signal
to a recorder, bar graph or
oscilloscope
Output for the binary defect
signal,
input for end signal
suppression in offline
applications
I/O socket for the coil
Connection of display device
Digital I/O
Toconnectperipheral devices suchasa recorder,bargraph oroscilloscope
on which the signal is graphically displayed, use the socket
Analog Signal 0 - 10V (RO= 100 Ohm).
Socket for
output signal
Analog signal
0-10 V
2
3
4
5
1
6
The pins are allocated as follows:
Pin Use
1 Test signal suppression + pole (5 – 30V)
2 Digital ground
3 Defect + pole (60V, 100mA), switching duration = min. 200 ms
4 Test signal suppression – pole (5 – 30V)
5 Defect – pole (60V, 100mA)
6 (+24V possible as supply for an external unit, if this is
necessary, Imax = 100mA)
6-pole socket for defect output and
end signal suppression

10 EDDYSENSOR Operating Manual
Digital I/O
6-pole socket for digital
switching and end signal
suppression
Switching duration:
min. 200 ms,
max. 60V 100mA
Internal
electronic
switch
Example of use:
alarm lamp
Pin Use
3 Defect + pole (60V 100mA),
switching duration = min. 200 ms
5 Defect – pole (60V 100mA)
Connection of PLC or similar To connect equipment such as a PLC, an alarm unit or a switch, use the
Digital I/O socket with a minimum signal duration of 200 ms.
Test signal suppression
The pins are allocated as follows:
Pin Use
1 Test signal suppression + pole (5 – 30V)
4 Test signal suppression – pole (5 – 30V)
A voltage of 5 - 30 V on this socket can be used to suppress the testing (for
example, in offline applications for end signal suppression).
Example
2
3
4
5
1
6

11
EDDYSENSOR Operating Manual
Front End Unit Back moduleFront module
The Front End Unit receives the signal from the coil inspecting the test
piece. When the equipment is first switched on, the filter designation
appears on the display, U1 for filters F1 and F2, and F3 for F3.
The bar graph display shows the peak amplitude of the signal from the
coil. The defect threshold value is fixed at 50% of the full bar graph display.
Any signal above this level (shown by a bar of red LEDs) is considered a
defect signal and any signal below the level (shown by a bar of green
LEDs) is not.
Front Module
There are three LEDs which indicate:
Defect LED - defects, i.e. when the signal from the coil exceeds 50%
of the bar graph display
Coil Error LED - coil defects such as a broken coil connection (this signal
is also available as an output), continuous error
Overload LED - any overload conditions, e.g. when the gain is set too
high.
LED monitoring function
The bar graph display
shows the peak amplitude
of the signal from the coil.
The defect threshold level
is fixed at 50%.
The amplitude below the
threshold level is indicated by
a bar of green LEDs and
above it by a bar of red LEDs.
Rocker switch to set
•gain between 0 and 55 dB
•high and low pass filters
These three LEDs
indicate defects, coil
defects and overload
Display of gain in dB
or filter data
EDDYSENSOR from above
FM1031F
Front
Back

12 EDDYSENSOR Operating Manual
The Gain switch on the front panel has three distinct functions. It is used
to set the:
• gain
• high pass filter and low pass filter
To change the function, you must change the mode.
The pictures of the display above illustrate the various configurations that
are possible. The mode that is currently active is indicated by the dots that
appear on the display. If the Gain switch is in the HP filter mode, a dot
appears in the centre. If it is in the LP filter mode, a dot appears to the right
of each digit. The default position of the Gain switch is that of the gain
setting. How to make the required settings is described below.
Set the gain required for the signal on the front panel display to between 0
and 55 dBs using the rocker switch. Set the gain high enough so that the
smallest detectable defect reaches approx. 60% on the bar graph display
but low enough to prevent noise interfering with the test results. The gain
is permanently stored after being set up.
Gain setting
Functions of the Gain switch
Basic setting
- Gain setting
High pass filter setting Low pass filter setting
Press
~1 s.
Press
~1 s.
Press
~1 s.
Inactive
~10 s.
Inactive
~10 s.
Summary of the displays Gain setting