YUSHI INSTRUMENTS
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point at this position, otherwise, it keeps unchanged.
Chapter 6 Application and Practice of Flaw Detection
This chapter introduces how to use YUT-2620 to test steel plate and welding line. This chapter is
based on the flaw detection methods and reports forms authorized by the National Nondestructive
Testing Personnel Qualification Test Committee. (Testing criterion is NB/T47013-2015).
6.1 Application on steel plate flaw detection
Using straight probe to detect the flawed area is the main application of the instrument for detecting
flaws of steel plate, which requires operators to identify and quantify the flaws.
6.1.1 The adjustment of testing scope
The adjustment of testing scope is mainly based on the thickness of the steel plate. By adopting
contact method, when the thickness of the steel plate is less than 30mm, B10 can be seen and the testing
scope should be adjusted to about 300mm. When the thickness is between 30-80mm, B5can be seen and
the testing scope should be about 400mm. When the thickness is more than 80mm, the frequencies of
bottom waves should be reduced while the testing scope should remain about 40mm.
6.1.2 The adjustment of sensitivity
Take flat-bottom test block as an example to illustrate the adjustment of sensitivity here. When the
thickness of the steel plate is more than 20mm, use the 50% first echo of φ5 flat-bottom test block as the
required sensitivity.