where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -

NDTSS - Non Destructive Testing Society of Singapore
Visit us at SINCE 2019
688 views
Technical Discussions
Gowri santhosh Palika
NDT Inspector,
Royscan engineering pte ltd, Singapore, Joined May 2008, 52

Gowri santhosh Palika

NDT Inspector,
Royscan engineering pte ltd,
Singapore,
Joined May 2008
52
03:30 May-02-2008
DAC

Hi,
To make DAC curve, we have to consider half skip, full skip and one and half skip distances. what is the necessity to take one and half skip distance?


 
 Reply 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 869

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
869
08:08 May-02-2008
Re: DAC
----------- Start Original Message -----------
: Hi,
: To make DAC curve, we have to consider half skip, full skip and one and half skip distances. what is the necessity to take one and half skip distance?
------------ End Original Message ------------

One of the reasons you want your signal amplitude for 1 1/2 skip distance is that you have a better representation with 3 points than 2. You are covering a greater distance. I know many codes requires that you inspect only in the first skip, but personnaly, I do go to 1 1/2 skip because of the Near Field. I've seen times when I couldn't see properly my signal after my IP, but the indication was quite visible after the first skip. Your indication may actually blend itself with your IP.

Presently, at one of my client's shop, we do inspection using Longitudinal Wave and our calibration is set to 100% Backwall. But the code also says that if your Initial Pulse cover more than 1/3 of the metal path, your calibration should be of at least 6 Backwall Reflections for the reason I have expressed ealier.

You've probably have noticed that your IP is always somewhat wider than your Backwall or your indications.

Hoping this will be of help...
Michel


 
 Reply 
 

Product Spotlight

TraiNDE UT

TraiNDE UT is a virtual tool associated with a signal database which simulates real inspection con
...
ditions for numerous applications (Type A/V1 block, DAC block, welds and plates).
>

NDTkit RT

NDTkit RT, TESTIA's Digital Radiography software The NDTkit product line software for X-ray analysi
...
s. NDTkit RT is a software benefiting from the Ultis kernel which is dedicated to radiographic image analysis. It offers a set of tools and filtering processes to assist RT operators in finding relevant flaws.
>

Semi-Automated Phased Array Immersion System for Small Composite Parts

Turn-key semi-automated system as an improved and affordable solution for inspection of small comp
...
osite parts. Includes support table, immersion tank, scanner, PA instrument, PC, Analysis software, database, wedge management and other options.
>

FD800 Bench Top Flaw Detectors

The bench-top FD800 flaw detector range combines state-of-the-art flaw detection with advanced mater
...
ial thickness capabilities. Designed for use in the laboratory these gauges are the tool you need for all your flaw detecting needs.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window