The new standard of eddy current structure test for production and laboratory.

Digital eddy current test instrument for nondestructive testing of components, mass produced parts and semi-finished products for material properties such as hardness, case depth, structure, tensile strength, heat treatment or alloy using Preventive Multi-Frequency Technology.

buttonHigh power modular instrument concept with max. 16 independent crack detection channels, max. 32 structure test channels and their combinations.

Description of product

The eddyvisor distinguishes itself with its high performance modular concept with max. 16 independently working crack detection channels and max. 32 structure test channels all in a very compact design. Additionally, it offers unique features for the realization of sophisticated test tasks using the eddy current technique, combined with the well known ibg test reliability and ease of operation.

The ergonomic interface enables easy and simple operation via touch screen. All functions and test results are captured at a glance. Digital processing of the measuring signal with unique processors, immediately after the pre-amplifier guarantees the greatest possible stability of test results.

The eddyvisor is based on the long proven ibg system concept. All coils, probes, rotating heads and other system components are standardized worldwide. So eddyvisor is the solution for new tasks and to upgrade existing production machines to equip them with state of the art eddy current technology.


ID coil for structure test on a contiuous velocity joint for correct case depth and position of hardness zone.

A difficult problem for in process inspection of mass parts is supervision of heat treatment results. Verification of features like correct case depth and hardness are of prime importance for meeting the quality standards of the final product. These features can be monitored by destructive methods like sampling but with concurrent high personnel and financial effort. Moreover, a sampling inspection is sensible for statistically distributed defects only. During heat treat processes in furnaces or induction hardening, accidents involving single parts and that violate statistical distribution laws happen. These “unexpected” defects can be missed by sampling. 100% testing is required to reliably detect them.

Eddy current structure test utilizing the well known Preventive Multi-Frequency Technology (PMFT) by ibg guarantees maximum test reliability in 100 % testing. Heat treatment results in serial testing can be monitored cost efficiently, quickly and reliably, and unexpected defects are detected with highest reliability. The eight test frequencies of the fundamental wave as well as analysis of two harmonics of the PMFT guarantee highest reliability. The field of application for PMFT with simultaneous harmonic analysis is very wide and includes testing surface hardness, case depth, intermediate structure, material mix-up and others.

Setting of the instrument is done with good parts only. Ten to 20 parts are presented to the instrument, and tolerance zones are formed automatically. Eddy current signals from subsequent parts are now compared with these good parts. That means that no artificial defects are required for calibration, only known good parts. Due to the high test speed and the easy setup a new test task is ready to start within shortest time. Another advantage is the multi-dimensional analysis of ibg test instruments. An individual tolerance zone is formed for each test frequency. If all tolerance zones are satisfied, one can assume that the tested part is okay. Even one single not satisfied tolerance zone classifies the part as not good.

Eddy current tests are always comparative tests with yes/no answer. Very small deviations in the group of parts can be detected. Eddy current cannot answer why there is a deviation. In case of a bad part another test is recommended like metallurgical methods to inspect the structure (cut) or a classic hardness test.


Fixture for eddy current structure test in the laboratory.

NEW: Simultaneous Harmonic Analysis iSHA
The relative permeability is strongly influenced by heat treatment processes. Hardened structures have a lower permeability than soft. Because the ibg Preventive Multi-Frequency Technology tests with small magnetic fields hardened OK parts show no saturation effects. It’s within the linear range of the hysteresis curve.

Harmonics occur by each hysteresis of the magnetisation curve of a test part in the coil arrangement. The sinusoidal current in the exciter coil leads to a sinusoidal field strength which induces a magnetic flux in the test part. Its chronological sequence, however, is (depending on formation of permeability) not sinusoidal anymore. Therefore the sequence of the magnetic flux in the receiver coil induces a distorted voltage, deviating from the real sine even at small field strengths. The fundamental waves, having been distorted by hysteresis, contain higher frequency harmonics. Fourier analysis of the distorted fundamental waves reveals the higher frequency harmonics, more precisely harmonics of the 3, 5, 7 or 9 times frequency. The analysis of these harmonics supplies a more detailed view of the magnetic features of the part and thus more exact information on the formation of microstructure. In addition, it offers significant advantages when suppressing interferences like batch scattering, part geometry and part temperature or positioning effects. Harmonic signals are very small. That’s why immense electronic effort is needed in order to distinguish them from the basic noise. Such small signals can be detected clearly and processed robustly by ibg’s unique digital eddyvisor instrument family.

An essential innovation is iSHA (ibg’s Simultaneous Harmonic Analysis) – combined with ibg’s PMFT it guarantees highest possible test reliability. It enables simultaneous calculation of vectors of the fundamental wave at eight frequencies and of two harmonics without extension of test time. It additionally uses high frequencies and their harmonics for a better solution of even smallest structure differences. Thus iSHA greatly enlarges the possibilities of the well-known Preventive Multi-Frequency Technology.

NEW: Temperature adaptive structure test iTAS
Eddy current testing is based upon the electric conductivity and the magnetic permeability characterising the material to be tested. Different materials and microstructures have different conductivities and permeabilities that are detectible by eddy current. However, both properties also show a temperature dependency. Electric conductivity decreases by 4% per 10°C. Variations of ambient temperature are compensated by ibg by means of the differential coil principle. Test coil is compensated by a separate compensation coil giving a differential test.
However, test parts are often heated up by production processes and cool down during pauses of production. Thus they have different temperatures when tested. This leads to an erroneous NG sorting.

ibg‘s new Temperature Adaptive Structure Test (iTAS) considers the influence of temperature fluctuation on the measuring values. If the temperature of the test parts can be captured by an external sensor that is directly connected to the eddyvisor, the influence of the temperature can almost be entirely compensated. Test parts appear as if tested at the same temperature. Pseudo reject is reduced and the test is more precise. The iTAS also enables quick visualisation of how big part temperature influence is in comparison with other parameter fluctuations (batch and dimension differences etc.) for a specific test application.


New: our new AutoStart allows an even faster and more precise start of the structure test than before. The graphic interface makes it very easy to adjust the AutoStart for quick and also for dynamic testing.

Features of structure test

  • Tolerance zones
    During material data recording the eddyvisor automatically generates elliptic tolerance zones calculated for reliable testing. A tolerance zone editor is integrated for special situations in the structure test field. A skilful operator may reestyle the fields as rectangle, or ellipse, reduced or expanded, rotated or moved, etc.
  • Test speed
    High speed testing within milliseconds. Using eight test frequencies and standard setting (25 Hz – 25 kHz), only 141 milliseconds are needed for the test. In high speed mode only 1 ms is needed for each test frequency > 5 kHz, very useful for very high speed dynamic testing.
  • iSHA harmonics analysis
    Eight test frequencies of the fundamental wave plus two harmonics (2nd to 9th arbitrary) for each of the eight test frequencies can be utilized without extension of test time. The standard setting is evaluation of the 3rd and 5th harmonic on each of the eight fundamental waves.
  • Display
    Display of test results as bargraph diagram, single ellipse or multiple ellipse display selectable.
  • Coils
    A multitude of standard encircling coils up to a diameter of approx. 500 mm and probes for structure test are available for standard applications. Special applications may be solved by custom designed inner diameter I.D. coils or by rectangular coils which are designed and manufactured in house. Monitoring of coil and cable failure as well as 50/60 Hz noise suppression can be activated.
  • Triggering of test
    Start of test can be done manually at touch screen, via PLC or optional start button. There is an auto-start function that detects the part in the test coil and activates testing immediately or after an adjustable delay time.
  • Test frequencies
    Eight frequencies in a range of 5 Hz to 3 MHz are selectable.
  • Classification
    Sorting of different materials and testing of mixed batches can be accomplished with the ibg classification function (OR-conjunction). Up to seven good part types with different characteristic can be taught and during testing compared to the taught types and classified according to their part type.
  • Bar and tube test (option)
    Bars, tubes and wire can be tested in line to verify material, heat treatment and density differences as well as structure changes. Two proximity switches are used to trigger start and end of test. Nearly the entire bar/tube length is tested. An integrated statistical evaluation of the good versus not good tests (absolute and percentage) is automatically updated. A threshold for an allowable percentage (adjustable) of not good tests can be utilized to eliminate rejects caused by irrelevant local material property variations (e.g. from cold working from handling.
  • Ergonomic design
    All functions and test results including for complex systems are clearly arranged to be viewed at a glance. This enables correct and easy operation even for inexperienced operators.
  • Stations and Locations
    The eddyvisor offers a unique station and location concept for solution of complex applications. Maximum eight stations can be defined which may include up to 32 locations. All test locations of one station belong to the same part and are summed up in a station result. This result can be taken for sorting. The part must be tested at all locations of that station in order to get a valid station result. Stations are independent from other stations. Different stations can take different operating conditions. For exapmle, one station can be testing parts, and another station can be recording new calibration data or being adjusted. In addition, each location has its own set of reference data and tolerance zones. For crack detection, for instance, it is possible to define different areas of a test part (faces, radii, undercuts etc.) and to test each of them with different settings switchable via PLC on the fly. So each area of a test part, including areas with high basic noise (e.g. radii) or with very low basic noise (e.g. high precision machined or super finished surfaces) can be tested with the setting optimised for that area without disturbing testing of the other areas.
  • View of test part
    At stations with at least two and maximum 22 locations a picture of the test part created by customer may be included. The test result of the single locations of the station is visualised by colouration of the test part picture. A huge help for the operator especially in test system with complex setup. These test part pictures can be displayed in the survey of all stations as well (however, w/o colouration of result).
  • Part types
    Maximum 100 part types (at more than eight locations max. 50) in crack detection and max. 250 part types in structure test with all settings and reference data can be stored in the device memory and switched over manually or via PLC for automated processes.
  • Part ID
    Test data for individual parts can be allocated to the part. The eddyvisor can be informed before the test of an alphanumeric serial number from a PLC or another system (QR-code reader or similar). This identity is connected with the related test data, stored in the eddyvisor and additionally written via the eddyLogger Software or as Q-DAS compliant set of data. Indispensable for back tracing individual parts.
  • History of reference parts
    The histogram displays the test results of all reference parts at a glance. When after recording of reference parts and afterwards crosschecking in the laboratory it is determined that a part is still not good, it can be removed from the reference parts with one keystroke.
  • History of sorting parts
    The multi-coloured histogram displays the test results of up to 1000 sorted parts and additionally the last 100 bad parts, so they can be observed at a glance and evaluated later. Test results of questionable rejected parts can be recorded as tentative reference parts and later destructively cross checked in the laboratory. If such questionable rejected parts are later found to be good, they can be added to the reference parts with one keystroke. Pseudo rejects can be diminished.
  • AQDEF quality data export Q-DAS standard compliant (option)
    Test data are transferred after termination of each test part via Ethernet to a protocol computer where the free eddyLogger Q-DAS software receives the data and provides them AQDEF compliantly to the QSSTAT interface. The software allows the user an individual configuration. The following options are available per test station: selection of data to be stored; storage with K-field or abbreviated separator spelling; memory format as DFD/DFX or DFQ files; free choice of amount of test parts to be stored per file. The eddyLogger software may record and administrate parallel the test data of several ibg instruments within one Ethernet network so that one acquisition computer is able to supervise several eddyvisor and/or eddyliner instruments.
  • Data storage in general
    Test results, part types and instrument settings are stored internally on a tough flash-memory and externally via USB stick. Test results may be additionally logged via network. A ring buffer logfile records all internal failures and allows fast debugging for service.
  • Automation without PLC
    Direct control of sorting devices, paint marking systems or indicating lamps is possible with the integrated 24 Vdc (2.5 amps) power supply, together with the autostart function providing a low cost solution for small automated systems without an additional PLC.
  • Counter preset
    The function “box counter” monitors the filling height of containers to avoid overfilling. Testing is paused automatically as soon as a preset value of tested parts is reached. The operator changes the containers and reset the counter, testing starts again automatically.
  • Remote control
    The eddyvisor is remote controlled by each network PC via VNC viewer software.
  • Access protection
    DThe instrument offers a multi-level access authorisation concept that operates by keyswitch.
  • Help function
    The user always has access to a context sensitive help function on the device screen which often renders a look into the manual unnecessary.
  • Languages
    Included are: German, English, Spanish, French, Italian, Czech, Polish, Portuguese, Chinese, Hungarian, Japanese, Korean and Russian. Other languages as option.
  • Screen
    Tough 15” TFT touch screen, colour display, resolution 1024 x 768 pixel, operable with gloves.

IO-ports An optically insulated interface with 32 in- and 32 outputs is available for PLC connection. As option, a further module with additional 32 in- and 32 outputs
can be installed. An allocation of the signals to the IOs is free in the eddyvisor.
XGA The screen may be displayed on another screen in XGA-resolution by means of the HDMI and display port connector. Essential for trainings.
Printer A usual printer can be connected via USB 2.0 or Ethernet to print screens or protocols.
USB 2.0 Two USB 2.0 ports at the front, one underneath for data storage.
Two models of eddyvisor are available: Desktop version eddyvisor D (with retractable feet, inclined) or as separated switch panel version with operating
unit eddyvisor HMI and measuring unit eddyvisor M.

Completely sealed and thus suitable for rough production environment.

Technical Data mains 100 – 240 V, 50/60 Hz, ambient temperature 0 – 45°C, relative humidity: max. 85%, non-condensing


Rear side eddyvisor equipped with (from left): 4-channel crack detection module, 8-channel structure test module, IO-module, mains



Galgenried 6
CH-6370 Stans Switzeland

+41 41 612 26 50