1、Profile
The magnetic powder detection technology is the most commonly used NDT methods, it is one of main testing ferromagnetic material surface and near surface defects. The current assolenoid style magnetic powder flaw detector, due to the design of the instrument itself, it can't avoid heavy equipment, need power, very difficult in aerial work . And in terms of technology, general electromagnetic flaw detector can only detect the surface 2 mm under the defects of conventional, and general ultrasonic detection can only detect 6 mm below the internal defects, so the 2 mm ~ 6 mm defect inspection is to be the blind spots.
Permanent magnetic alternating flaw detector is a leap of the magnetic powder detector in nondestructive testing methods , it broke through the limitation of the previous magnetic powder flaw detector. In addition it broke through the limitation of magnetic the current magnetic particle testing can only testing metal surface defects,.And it make up the limitations of some scopes that conventional ultrasonic testing can't detect , up to 6 mm depth detection, especially for the aerial work and field without the power of place.
Permanent magnetic alternating detector, not need to power, need not other instruments, and conveniently operate, simple, light weight, easy to carry, which is the development direction of the nondestructive testing magnetic powder examination instrument .
2、Working theory：
As everyone knows,AC electromagnetic field have the effect of skin,so which have a higher sensitivity defect the surface. In addition, because of the continuously change of the AC direction, this also can stir the magnetic powder, which is benefit the migfation of the magnetic powder, so as to improve the detection sensitivity. Dc magnetic field have not the skin effect , so relatively speaking,its magnetic field insert the surface more deep, help to find a deeper defects. Permanent magnetic alternating detector, through the two pieces of permanent magnet, magnetic heads, his hands and work piece formed a magnetic circuit, so as to produce a alternating magnetic field, when magnetic field achieve maximum, thus can provide a direct current which is equivalent to the magnetic field which generated by DC. That is both ac and dc effect, so as to achieve the purpose of the test.
3、Features
(1) Light weight，only have about 2.5kilogram
(2) Do need the light source
(3) Only need a host,need not any fitting,convenient to work in high place or outdoor
(4) The strength of magnetic field can be adjusted, and two magnet synchronous rotation, to provide enough magnetic field intensity.
(5) The ability of lifting is 225N。
(6) Can sensitively detect the defection of 6 mm under the workpiece surface.
(7) The country standard type A1.60/100can be displayed clearly.
(8) After detection,it is easy to put down it .
4、Alternating flaw detector technology parameters
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Parameter/type
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PMA-225
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Probe type
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Magnetic probe
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Probe space
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110mm
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Lifting ability
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225N
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Testing depth
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0mm～6mm
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Host size
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220mm*150mm*38mm
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Probe weight
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1.95kg
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The whole weight
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2.5kg
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