OmniScan MX EC

Eddy Current Inspection

Eddy Current Technology
Eddy current (ECT) technology is a noncontact method for the inspection of metallic parts. In this technique, the probe, which is excited with an alternating current, induces eddy current in the part under inspection. Any discontinuities or material property variations that change the eddy current flow in the part are detected by the probe as a potential defect.
Over the years, probe technology and data processing have continuously progressed so that the eddy current technique is now recognized to be fast, simple, and accurate. This is why the technique is widely used in the aerospace, automotive, petrochemical, and power generation industries for the detection of surface or near-surface defects in material such as aluminum, stainless steel, copper, titanium, brass, Inconel® and even carbon steel (surface defect only).

Benefits of Eddy Current
Eddy current offers the following capabilities:

• Quick, simple, and reliable inspection technique to detect surface and near-surface defects on conductive material
  
• Can be used to measure material electrical conductivity.
  
• Measurement of nonconductive coating
  
• Hole inspection with the use of high-speed rotating scanner and surface probe

Eddy Current Probes
R/D Tech's standard eddy current probes are available in different configurations:

• Bolt hole probes
  
• Surface probes, in various shapes and configurations
  
• Low-frequency Spot and Ring type probes
  
• Sliding probes
  
• Wheel probes
  
• Conductivity probes
  
• Speciality probes made for specific applications
  Reference standards with EDM notches can be manufactured according to the application specifications.

Probes used to perform eddy current inspections are made with a copper wire wound to form a coil. The coil shape can vary to better suit specific applications.

a-The alternative current flowing through the coil at a chosen frequency generates a magnetic field around the coil.
b-When the coil is placed close to an electrically conductive material, eddy current is induced in the material.
c-If a flaw in the conductive material disturbs the eddy current circulation, the magnetic coupling with the probe is changed and a defect signal can be read by measuring the coil impedance variation.

Surface preparation is minimal. Unlike liquid penetrant or magnetic particle inspection, it is unnecessary to remove the paint from the surface to inspect the parts.

Learn more about our eddy current probes

Eddy Current Software

Impedance Plane and Strip Chart Display

• User-selectable screen persistency
  
• Two-frequency operation and automatic mixing capability
  
• Reference signal overlay can be kept on the screen for easier signal interpretation.
  
• Freeze mode allows signal rotation and gain adjustment without having to hold the probe on the part.
  
• Zoom and Best Fit functions

Conductivity and Thickness Measurement Mode

• Simple step-by-step calibration procedure

Conductivity and thickness measurement

• Material conductivity or coating thickness are displayed with very large numerals.
  
• Impedance plane display for signal representation during measurement
  
• Instruction window guides the operator during the measurement process.
  
• Adjustable threshold represents the measurement values in blue, green, or red.
  
• Measurements can be stored in a tabular report.

Rotating Probe Operation

Bolt hole inspection using C-scan display or conventional sweep mode

• Impedance plane with synchronized sweep trace displayed simultaneously
  
• Adjustable impedance plane persistency to show one or several probe rotations on the screen
  
• Scrolling C-scan display to represent the inspected area in a 2-D color map
  
• High acquisition rate allows smooth signal representation and high-speed rotation.
  
• Real-time data interpolation or compression to compensate for rotation speed variation
  
• Full data recording capability
  
• Special median high-pass filter provides a stable trace.

C-Scan Surface Mapping

• Support of two encoder inputs to connect various scanners
  
• Real-time C-scan mapping display with impedance plane and strip chart view

Advanced Real-Time Data Processing

• Three alarms can be defined with various shapes to activate LED, buzzer, or TTL output.
  
• High-pass, low-pass, and specialized filters

Eddy Current Modules Specifications*