What is eddy current technique?
Eddy current technology is an electromagnetic technique widely used in the aerospace, automotive, petrochemical, and power generation industries for the inspection of metallic structures. In this technique, the probe, which is excited with an alternative current, induces eddy current into the part under inspection.
How do eddy current sensors work?
Eddy Current Sensors work in magnetic fields. The driver creates an alternating current in a sensing coil at the end of a probe. The alternating current then creates an alternating magnetic field which induces smaller currents within the target material, these currents are referred to as Eddy Currents.
What are eddy current probes?
In an eddy current probe, an alternating current flows through a wire coil and generates an oscillating magnetic field. That eddy current flowing through the metal will in turn generate its own magnetic field, which will interact with the coil and its field through mutual inductance.
What is eddy current and its application?
Strong eddy currents are set up in the metal produce so much heat that the metal melts. This process is used in extracting a metal from its ore.The arrangement of heating the metal by means of strong induced current is called the induction furnace. (2)-Induction motor, the eddy currents may be used to rotate the rotor.
Can eddy current detect cracks?
Eddy current allows analysts to inspect materials on a surface and near-surface level. The best eddy current instruments can detect cracks for complex inspections like tubing via multiple frequencies and dual options, and can pick up developing cracks as small as 0.1 mm or less in depth.
What is the advantage of eddy current?
The advantages of eddy current testing are: Sensitivity to surface defects. Able to detect defects of 0.5mm in length under favourable conditions. Can detect through several layers.
Which type of material can be detected by eddy current position sensor?
Explanation: Eddy current type displacement sensor can detect metal objects because it uses high frequency magnetic field for the detection of objects.
How are eddy currents produced?
They can be created when a conductor is moving through a magnetic field, or when the magnetic field surrounding a stationary conductor is varying i.e. anything which results in the conductor experiencing a change in the intensity or direction of a magnetic field can produce eddy currents.
What are the two applications of eddy current?
Mention any two applications of eddy currents.
- Induction furnace (heating effect of eddy current)
- Dead-beat galvanometer (electromagnetic damping)
- Electric brakes, induction motors,
What is eddy current in simple words?
: an electric current induced by an alternating magnetic field.
What is the difference between induced current and eddy current?
The main difference between eddy current and induced current is that induced current refers to currents flowing in coils of wire in a closed circuit whereas eddy current refers to loops of currents flowing within pieces of larger conductors due to electromagnetic induction.
What are disadvantages of eddy current?
Disadvantages of Eddy Currents: There is a major heat loss during cycling eddy currents due to friction in the magnetic circuit, especially where the core is saturated. Thus there is the loss of useful electrical energy in the form of heat. There is magnetic flux leakage.
What are the different types of eddy current probes?
Olympus eddy current probes consist of the acquired brands of Nortec and NDT Engineering. We offer more than 10,000 standard and custom designed eddy current probes, standard references, and accessories. This section features many of the standard design probes that are available in a wide range of diameters, frequencies, and connector styles.
Where did the idea of eddy current testing come from?
Eddy current testing (ECT) as a technique for testing finds its roots in electromagnetism. Eddy currents were first observed by François Arago in 1824, but French physicist Léon Foucault is credited with discovering them in 1855. ECT began largely as a result of the English scientist Michael Faraday’s discovery of electromagnetic induction in 1831.
How are eddy currents formed in a sensor?
Eddy current sensors uses the principle of eddy current formation to sense displacement. Eddy currents are formed when a moving or changing magnetic field intersects a conductor or vice versa. The relative motion causes a circulating flow of electrons, or currents, within the conductor.
How is an alternating magnetic field used in eddy current testing?
In the traditional version of eddy current testing an alternating (AC) magnetic field is used to induce eddy currents inside the material to be investigated.