YUSHI INSTRUMENTS
33
thickness of the steel plate is more than 20mm, use the 50% first echo of φ5 flat-bottom test block as the
required sensitivity.
Put the
probe on the flat-bottom test block, move the probe to find out the biggest echo ofφ5
flat-bottom hole. Press
to enter the parameter menu. Use the direction keys to adjust Gain and
set the first echo to 50% of the scale. The readings of the gain is the sensitivity degree of flaw
detection. Finally scan and detect flaws by putting the probe on the steel plate to test.
6.1.3 The identification of flaws
In the process of flaw detection, observe the waveform on the screen to judge the flaws according to
the flaw waves and bottom waves. According to NB/T47013-2015, the following situations can be
identified as flaws.
The first reflected waves of flaws F1≥50
％
.
First bottom waves B1
＜
100
％
, the ratio between first flaw waves F1 and first bottom waves B1
being F1/B1≥50
％
.
First bottom waves B1
＜
50
％
.
6.1.4 Flaw Evaluation
When the flaws is identified during the detecting process, it is necessary to evaluate the location,
size and estimate the nature of the flaw.
6.1.5 Flaw Quantify
Length testing method is usually adopted to test its length and area in steel plate flaw detection.
According to NB/T47013-2015:
The arrows represent the scan directing
