Eddy Current Comparator I20         

Test part: hardened / not hardened

Test device / Rotary plate


During the production of safety relevant fixture parts, for instance, for automotive seat frames, one must ensure that all assembled parts also hardened. The same applies to products, which are exposed to extended wear and tear in order to avoid early failures. In this application the customer wanted to test sheet metal parts of the approximate size of 70 x 80 mm up to 75 x 150 mm. As the parts are assembled in an automatic production line these tests must be done automatically in order to identify parts which not hardened or have other defects in order to eliminate them from the process.
 
The very cost-effective Eddy Current Comparator I 20 consisting of two sensors facing each mounted in a
C-frame and connected to the control unit. The sensor principle is the so-called transmission principle. The transmitter generates an electromagnetic field which is dampened by the test sample in the sensor gap. The voltage measured at the receiver corresponds to the magnetic and the electrical properties of the parts being tested. Because the hardened parts differ from parts which are not hardened by the magnetic and electric properties: the system has a high discrimination capability. The control unit will detect this difference and issues an output signal in order to discharge the defective part from the process.
 
A simple Teach-in procedure with two test samples -- okay and not okay -- is all that is necessary to set up the unit automatically. The control unit I 20 can store parameters of 255 different test samples thereby covering a very large parts spectrum. The switching threshold for discriminating between good and bad parts can be set by the customer.


The Eddy Current Comparator I 20 is also suitable for differentiating between:

metal grades
different alloys
thickness differences


Technical Data:

sensor gap     20 to 80 mm
parts size         from about ca. 50 x 50 mm
material type     steel
sensor principle     eddy current
static or dynamic     calibration
velocity        maximum 1 m/s
test duration    from 2 to 250ms
performance max.    36.000 pieces/hour

As interface to the PLC the parallel I/O interface is available as well as all customary field buses such as PROFINET, PROFIBUS, EtherCAT, DeviceNET, Ethernet/IP or CC-Link.