Epson USN 52L, USN 52R manual Carrying out a DGS evaluation, Example

Carrying out a DGS evaluation Operating the DGS

Example:

If the surface of the test object is greatly corroded and the reference echo originates from a smooth surface reference block, then the sensitivity is reduced (e.g. by 8 dB). Correspondingly, the value for the transfer correction must be entered negative, e.g. T-CORRECTION = -8 dB.

This method is different from the usual way. Normally, transfer loss is the value by which the gain must be increased in order to compensate for the sensitivity loss caused by a rougher surface.

You have now made all basic adjustments and are able to carry out a DGS evaluation.

3.3Carrying out a DGS evaluation

When carrying out a DGS evaluation, you compare the reflecting power of a natural reflector with that of a disk- shaped reflector. You are not making any flaw size esti- mation.

–Make the basic adjustments for a DGS evaluation.

–Specify the reflector type and size.

–Switch to A-scan display: F

–Couple the probe and the reference block, and peak the reference echo.

–Tag the function group DGS: I

–Adjust the required amplitude height of the reference echo in the GAIN function: N or O

–Set the gate to the reference echo.

Krautkramer USN 52R/USN 52L Option DGS Issue 02, 03/99 DGS-23