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 -
700 views
Technical Discussions
Ramalingam
NDT Inspector,
QTech Instutitu of Nondistractive Testing, India, Joined Sep 2009, 1

Ramalingam

NDT Inspector,
QTech Instutitu of Nondistractive Testing,
India,
Joined Sep 2009
1
19:21 Sep-29-2009
what is mean by tandam echo

dear sir
i am work in forging company
some doutful question in UT what is mean by tandam echo

 
 Reply 
 
Peter Bruckner
NDT Inspector, NDT Manager
United Kingdom, Joined Jul 2008, 21

Peter Bruckner

NDT Inspector, NDT Manager
United Kingdom,
Joined Jul 2008
21
23:08 Sep-29-2009
Re: what is mean by tandam echo
In Reply to Ramalingam at 19:21 Sep-29-2009 (Opening).

Hi Ramalingam,
Usually tandem testing involves 2 identical shear wave probes facing the same direction on the surface of the bar a fixed distance apart. The distance between the probes is 1/2 skip, for 45 degree probe that is the thickness or diameter of the bar under test.
The only type of defect this will find is a planar one transverse to the beam at 1/2 thickness/diameter. The test standard usually consists of a flat bottomed hole drilled in the end of the bar.

I hope this is of some assistance.
Regards
Peter

 
 Reply 
 
Uli Mletzko
R & D, Retired
Germany, Joined Nov 1998, 89

Uli Mletzko

R & D, Retired
Germany,
Joined Nov 1998
89
11:44 Sep-30-2009
Re: what is mean by tandam echo
In Reply to Peter Bruckner at 23:08 Sep-29-2009 .

Hi Peter and Ramalingam,

the expression 'tandem' originates from a bicycle type for two persons, where the second person is sitting behind the first, both looking into the forward direction, and both pedaling.

In UT the distance between the two probes is not limited to 1/2 skip, but usually ist smaller than full skip. In testing of medium and heavy wall nuclear components, tandem is a standard system at least in Germany. We have arrangements of e.g. 3, 4 or 5 or more probes, each behind the other. Usually one probe acts as transmitter, the other ones as receivers. All sound pathes are reflecting on the surface opposite to the probe system, so in general you can inspect only components with parallel or coaxial surfaces. Using more than two probes will split the cross section to be inspected into several layers.

The presumed defects at tandem UT are not transverse to the sound beam, but perpendicular to the surface.

As far as I can remember, tandem UT was invented about 1970 by the German institutes and companies BAm and/or AEG, MAN and Siemens.

Regards
Uli Mletzko (retired, from MPA/University of Stuttgart/Germany)

 
 Reply 
 

Product Spotlight

CIVA 2020 UT Module

CIVA NDE Simulation Software is the world leader of NDT Simulation. The UT simulation Module incl
...
udes: - "Beam computation": Beam propagation simulation - "Inspection Simulation": Beam interaction with flaws or specimens The user can simulate a whole inspection process (pulse echo, tandem or TOFD) with a wide range of probes (conventional, Phased- arrays or EMAT), components, and flaws.
>

NOVO Armor 15 & NOVO Armor 22

The Armor Kit Contains the NOVO Armor, which provides additional mechanical protection to the NOVO 1
...
5WN & NOVO 22WN Detectors, the Armor Stand and a traveling soft cover. - Newest shock absorbent technology case - Water resistant design - Supports wired & wireless communication - Multiple positioning options - Tripod connection using the Built-in 1/4” threads - Simple Detector battery replacement
>

Research Center IDEKO develops an ultrasonic train wheel inspection system for CAF

The Basque Research centre IK4-IDEKO has developed a state-of-the-art ultrasonic inspection system f
...
or the train wheel. This system secures a sound condition of train wheels and is thus a significant contribution to rail transport safety. The device was delivered to CAF recently and its use allows the manufacturer to become an approved supplier of rolling stock in Italy, as it meets the demanding homologation standards of this country. \\\\r\\\\n
>

AIS229 - Multipurpose Real Time System

Latest standard & automatic real time system developed by Balteau. The AIS229 has been designed to
...
do series inspection in a wide variety of industry. Composed of a shielded cabinet, 5 axis manipulator, x-ray generator and tubehead from 160kV to 225kV, a fl at panel & much more, the AIS229 is most certainly one of the most multipurpose RTR system available on the market.
>

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