Steps Using Ultrasonic Beam Plotter 1. Draw the the actual weld weld profile profile on the the transparent transparent(plas (plastic) tic) ,draw ,draw also the the mirror mirror image. 2. If you you got a signal, signal, maximi maximize ze and read read the the BPL value .For examp example le 42mm 42mm 3. From the the test plate, plate, measur measuree the distance distance from from the the Probe Index Index to the Center Center of of the Weld Weld using using a ruler. This is called the Stand-off Distance.For example example 40mm. 4. On the slide, slide, put the probe probe index index at StandStand- Off(40 Off(40mm mm )from )from the center center weld. weld. See below. below. Stand Off=40mm
Center of weld
60°
BPL
5. Mark the BPL BPL (42mm)on (42mm)on the slide. slide. This This is where where the defect defect is located located on the the weld on its its mirror mirror image. Note that, If the BPL does not landed on the weld area, it means it is a non-relevant indication. Center of weld
Stand Off=40mm 20
10
30
10
10 20 30
20
40
Defect BPL
30
6.Draw straight line from the defect upwards to know the exact location above the surface and depth of the defect on its original image. 7. From the slide, read the surface distance and mark on the test plate. Surface Distance=36mm
Center of weld 20
10
30
Depth= 3mm 10
10 20 30
20
40
Defect BPL
50 30
Note: Stand –Off Distance= Distance Distance from Probe Index to the weld center line Surface Distance = Distance from Probe Index to the defect above the surface.
