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Wave User Manual
Version 4
12.3.2
TCG Sizing Options
After creating a TCG curve, you can easily switch from TCG to DAC and back, via the
DAC to TCG
button. Once the
TCG
curve is created, you can still set the
Transfer Loss
making the curve visible, as shown on the following figure.
Figure 47
–
TCG sizing options available
12.4
DGS
Distance-gain-size
diagram is a theoretical model for discontinuity sizing evaluation. This
model allows technicians to correlate discontinuity size between natural flaws and
theoretical reflectors in terms of distance compensation, and without requiring a large
range of reference standards in order to establish an evaluation curve.
DGS flaw sizing shows the sound response from “equivalent reflectors” of different sizes
at distinct depths, by performing mathematical predictions in terms of probe effective
diameter, frequency and near-field length.
When performing DGS evaluation, keep in mind that this defect sizing method shows
some limitations and it may lead to no definitive conclusions in some cases. As far as
discussed above, it is a predictive method and it tends to work better on standard
configurations, circular probe elements and narrow band.
12.4.1
Performing a DGS Calibration
Prior to generating the DGS evaluation curve, you must be in possession of a standard
test block with a reference reflector in order to define a reference point. A standard test
block must have one of the following reflectors:
●
Side-drilled hole
–
SDH
