Eddy Current: Amperage
Eddy Current 1. The principles of eddy current testing depend on the process of electromagnetic induction. 2. This process includes a test coil through which vary or alternating current (AC) is passed. 3. A varying current flowing in a test coil produces a varying electromagnetic field around the coil,
As shown in this diagram
Amperage * # of coils= strength of magnetic field
4. The electromagnetic field produced around the coils is directly proportional to the magnitude of applied current, rate of change in current or frequency and the coil parameters. 5. Coil parameters include: Inductance, diameter, length, and thickness, number of turns of wire and core material. 6. Electrical current is defined as the movement of electrons through a conductor 7. The unit of current is the ampere a. Ampere symbol is “A” b. An amp = Coulomb/sec. c. Coulomb= 6.25x1018 Electrons 8. A Conductor is any material that is capable of carrying electrical current, such as copper or iron. 9. Wood and plastic are not conductors. 10. Whether a material can conduct electricity or not depends on the structure of the individual atoms in the material d. 3 or less valence electrons makes for a good conductor 11. Ferromagnetic: Very little to some ability to take on a magnetic field e. Diamagnetic- essentially an insulator f. Paramagnetic- Only magnetically attracted when an external magnetic force applied. i. Austenitic stainless steel 12. Voltage is the push
Electromotive Force 1. Electromagnetic force is the electrical energy derived from mechanical, chemical, or other form of energy that must be applied across the material to force the electrons to move 2. The unit of the electromagnetic force is called the VOLT 3. Resistance is the opposition to current flow.
Resistance
1. In an alternating current circuit containing only resistance, the
As shown in this diagram
Amperage * # of coils= strength of magnetic field
4. The electromagnetic field produced around the coils is directly proportional to the magnitude of applied current, rate of change in current or frequency and the coil parameters. 5. Coil parameters include: Inductance, diameter, length, and thickness, number of turns of wire and core material. 6. Electrical current is defined as the movement of electrons through a conductor 7. The unit of current is the ampere a. Ampere symbol is “A” b. An amp = Coulomb/sec. c. Coulomb= 6.25x1018 Electrons 8. A Conductor is any material that is capable of carrying electrical current, such as copper or iron. 9. Wood and plastic are not conductors. 10. Whether a material can conduct electricity or not depends on the structure of the individual atoms in the material d. 3 or less valence electrons makes for a good conductor 11. Ferromagnetic: Very little to some ability to take on a magnetic field e. Diamagnetic- essentially an insulator f. Paramagnetic- Only magnetically attracted when an external magnetic force applied. i. Austenitic stainless steel 12. Voltage is the push
Electromotive Force 1. Electromagnetic force is the electrical energy derived from mechanical, chemical, or other form of energy that must be applied across the material to force the electrons to move 2. The unit of the electromagnetic force is called the VOLT 3. Resistance is the opposition to current flow.
Resistance
1. In an alternating current circuit containing only resistance, the