CHAPTER 4 EDDY CURRENT INSPECTION METHOD SECTION I …

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TO 33B-1-1NAVAIR 01-1A-16-1TM 1-1500-335-23CHAPTER 4EDDY CURRENT INSPECTION METHODSECTION I EDDY CURRENT INSPECTION (ET) CAPABILITIES OF Introduction to Eddy CURRENT METHOD is used to detect discontinuities in parts that are conductorsof electricity. An eddy CURRENT is a circulating electrical CURRENT induced in a conductor by an alternating magnetic field. Aneddy CURRENT instrument generates an alternating CURRENT that is designed to go through a coil of copper wire that has beenplaced in a holder called a ''probe.'' This results in the coil producing an alternating magnetic field that when placed near aconductor, generates electrical currents within the conductor (Figure 4-1). When these eddy currents encounter an obstaclesuch as a crack, the normal path and strength of the currents is changed and this change is detected, processed and thendisplayed on the instrument CURRENT INSPECTION is a ''reference'' type INSPECTION .

Calibration standards are also used for thickness measurements and conductivity testing. The term ''calibration'' refers to the use of standards directly traceable to a National Institute of Standards and Technology (NIST) standard that is government controlled. ... substrates. 4.1.4 Advantages of the Eddy Current Method.The following are some ...

  Calibration, Substrates