STRESSVISION belongs to a radically new class of flaw detectors.
It is known that "necessary and sufficient" conditions of defect development are:
à) for blowholes – the presence of MSC without prevalent direction of a high PMSD gradient;
b) for slip lines (ductile failure lines) – a high PMSD gradient without a distinct MSC;
c) for cracks – the presence of MSC with adjacent high PMSD gradient in one of directions.
All traditional flaw detector types are designed to detect such defects of metal structures as lack of metal continuity and foreign inclusions. A decision about classification of hazard of detected defects is made on the basis of defects’ size and spatial position. However, a significant portion of such defects is not dangerous for the structure since they either do not create MSC or do not lead to significant growth of PMSD gradient. On the other side, many micro defects cannot be detected by the known flaw detection methods, though they actually create the above-mentioned "necessary and sufficient" conditions. Therefore, the known types of flaw detectors are characterized by the rates of passing dangerous areas unnoticed and false alarms unacceptable for the engineering practice. In scanners of "STRESSVISION" series, such situations are fundamentally impossible.
Electromagnetic (magnetoanisotropic) scanner-defectoscopes "STRESSVISION" use the effect of magnetic anisotropy of ferromagnetic materials exposed to mechanical stress. Due to forming a test magnetic field of a special configuration, account of optimum information contained in a magnetic hysteresis loop and a new algorithm for processing the information received, the accuracy and validity of PMSD assessment results and MSC distribution parameters have increased significantly. Further, it has been possible not only to eliminate negative influence but also to use such phenomena as magnetomechanical and magnetoelastic hysteresis, etc., which have a disastrous effect on results of inspection by traditional magnetic methods of flaw detection (coercimetric, by flux-gate meter or using eddy currents) and by slip line indication methods (known as MMM – "metal magnetic memory method"). The method allows detection of mechanical stress anomalies not only in surface layers but also in deep metal layers (patented). Knowledge of MSC and PMSD, as follows from the classic theory of strength of materials, enables one to assess the hazard degree of the examined area at once, without any additional calculations.
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Operating principle 
