Epson USN 52L, USN 52R manual Diameter of the equivalent

Preparing the DGS evaluation

Operating the DGS

For the reference echo you need a test block with a known reflector. This reflector can be one of the follow- ing types:

•backwall

•disk-shaped reflector

•side-drilled hole. With known diameter of the side- drilled hole, the diameter of a corresponding disk- shaped reflector can be calculated, provided that the

following requirements are met:

DSDH ³ 1,5 l s ³ 1,5 N

with DSDH:	diameter of side-drilled hole
s:	sound path in the test object
l:	wavelength in the test material
N:	near-field length of the probe used
	in the test material
DESR:	diameter of the equivalent
	disk-shaped reflector
DESR =		Ö	2
	Ö p lÖsDSDH

Operation

HNote:

Before measuring, use M to select the setting PEAK in MEASURE. In addition, activate the gate.

–Connect the required probe to the USN 52 R and select a suitable reference block for receiving the reference echo.

–Adjust the A-scan and digital display (please refer to USN 52R/USN 52L Operating Manual, Chapter 5).

AAttention:

Proper A-scan and digital calibration will

assure that the MTL VEL and ZERO parameters are set correctly, which is necessary for an accurage DGS curve.

–Switch to the second operation level: X

–Tag the function table DGS: T or V

–Tag the left column of the DGS function group using J or C.

–Select the required probe number.

Krautkramer USN 52R/USN 52L Option DGS Issue 02, 03/99 DGS-21