Electromagnetic testing emt-mft chapter 9b

More documents

Recommendations

Info

Barkhausen Noise The Barkhausen effect is a name given to the noise in the magnetic output of a ferromagnet when the magnetizing force applied to it is changed. Discovered by German physicist Heinrich Barkhausen in 1919, it is caused by rapid changes of size of magnetic domains (similarly magnetically oriented atoms in ferromagnetic materials). Barkhausen's work in acoustics and magnetism led to the discovery, which provided evidence that magnetization affects whole domains of a ferromagnetic material, rather than individual atoms alone. The Barkhausen effect is a series of sudden changes in the size and orientation of ferromagnetic domains, or microscopic clusters of aligned atomic magnets (spins), that occurs during a continuous process of magnetization or demagnetization. The Barkhausen effect offered direct evidence for the existence of ferromagnetic domains, which previously had been postulated theoretically. Heinrich Barkhausen discovered that a slow, smooth increase of a magnetic field applied to a piece of ferromagnetic material, such as iron, causes it to become magnetized, not continuously but in minute steps. Charlie Chong/ Fion Zhang http://en.wikipedia.org/wiki/Barkhausen_effect
Barkhausen noise: Magnetization (J) or flux density (B) curve as a function of magnetic field intensity (H) in ferromagnetic material. The inset shows Barkhausen jumps. Charlie Chong/ Fion Zhang http://en.wikipedia.org/wiki/Barkhausen_effect
Page 1 and 2: Electromagnetic Testing MFLT/ ECT/
Page 3 and 4: Ship building Charlie Chong/ Fion Z
Page 5 and 6: Offshore Structures & Appurtenances
Page 13 and 14: Power Piping Charlie Chong/ Fion Zh
Page 15 and 16: Charlie Chong/ Fion Zhang
Page 17 and 18: Fion Zhang at Shanghai 2015 Februar
Page 19 and 20: Chapter 9B: Magnetic Field Testing
Page 21 and 22: Keywords: Field of magnetic materia
Page 23: Although it is conceivable that lea
Page 27 and 28: Barkhausen noise A coil of wire wou
Page 29 and 30: A set-up for non-destructive testin
Page 31 and 32: Magnetic Dipole Charlie Chong/ Fion
Page 33 and 34: If a slot is cut in the rod, as ill
Page 35 and 36: 2.2 Experimental Techniques. One of
Page 37 and 38: It is possible to generate a magnet
Page 39 and 40: The flaw leakage field can be detec
Page 41 and 42: Fig. 3 Flux leakage measurement usi
Page 43 and 44: Unlike the inductive coil, which pr
Page 45 and 46: There are, however, many situations
Page 47 and 48: Fig. 5 Dependence of magnetic signa
Page 49 and 50: Fig. 6 Characterization of a ferrit
Page 51 and 52: PART 2. Principles of Magnetic Char
Page 53 and 54: Hysteresis Curves Charlie Chong/ Fi
Page 55 and 56: Nevertheless, the prospect of nonde
Page 57 and 58: Curie temperature Below T c Ferroma
Page 59 and 60: Paramagnetism The magnetic moments
Page 61 and 62: Antiferromagnetism The magnetic mom
Page 63 and 64: Fig. 7 Experimental arrangement for
Page 65 and 66: The review articles and conference
Page 67 and 68: Leakage field sensors are mounted b
Page 69 and 70: In addition to systems for inspecti
Page 71 and 72: The flux leakage method is also fin
Page 73 and 74: Another area in which the flux leak
Page 75 and 76:
Finally, the flux leakage method ha
Page 77 and 78:
Steel rebars and cables in a large
Page 79 and 80:
Fig. 10 Effect of mechanical hardne
Page 81 and 82:
Keywords: • For one alloy, AISI 4
Page 83 and 84:
Offshore Structures Charlie Chong/
Page 85 and 86:
VLCC Charlie Chong/ Fion Zhang
Page 87 and 88:
Offshore Structures Charlie Chong/
Page 89 and 90:
Pipeline & Piping Charlie Chong/ Fi
Page 91 and 92:
Charlie Chong/ Fion Zhang
show all

Electromagnetic testing emt-mft chapter 9b

Create successful ePaper yourself

Delete template?

Save as template?