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 -

666 views
Career Discussions
wolfgang Bisle
R & D, Project leader & Group Leader InService Inspect.
Airbus Deutschland GmbH, Germany, Joined Jul 2000, 35

wolfgang Bisle

R & D, Project leader & Group Leader InService Inspect.
Airbus Deutschland GmbH,
Germany,
Joined Jul 2000
35
07:56 Feb-10-2004
Re: NDT Reliability methodology -- other people interested

ate you need a high number of samples without discontinuities... a very expensive situation, if you declare only a complete testspecimen to be "one" sample...

Hope I have put the situation in correct words as I am not a "native english speaking expert in statistics", so some expressions used in german for this topic can't be easily retrived from regular dictionaries (I mostly use http://dict.leo.org - a very good living project of the univ. of Munich), sometimes it is hard for us to hit the definition 100%.

Conclusion: I like this discussion you did, very much and maybe it gives us some additional ideas to improve our work to the benefit of safety


--
This message was posted into the NDT.net Forum.
http://www.ndt.net/wshop/forum/forum-2.htm
Please do not reply to email: forum@ndt.net
For your reply to this message go to:



    
 
 
Terry Oldberg
Engineering, Mechanical Electrical Nuclear Software
Consultant, USA, Joined Oct 1999, 42

Terry Oldberg

Engineering, Mechanical Electrical Nuclear Software
Consultant,
USA,
Joined Oct 1999
42
01:11 Feb-10-2004
Re: NDT Reliability methodology -- other people interested
Dear Wolfgang:

As you have noted, German-English translation of statistical terms can be a barrier to communication about NDT's research protocols. Another, which you have not noted, is that misuse of statistical terms among NDT's native English speakers, native German speakers and others can be a barrier to communication.

For example, in the U.S. Nuclear Regulatory Commission's report on its study of NDT reliability in
pressurized water reactor steam generator tubes, the "probability" of detection cannot be "probability," as this term is used in mathematics. This follows from the fact that probability theory is empirically
invalidated by the test and associated research protocol.

Because "probability" has sometimes been misused
in this way and because this misuse has sometimes obscured flaws in NDT's reliability studies, one should be careful in one's use of this term in discussions such as this one. In particular, I urge avoidance of the terms "Probability of Detection," "POD," "Probability of False Call," "False Call Rate," and similar terms in circumstances in
which the empirical preservation of probability theory has not been demonstrated.

"Sample" is another of these problematic terms. In statistical research, it designates a subset of the
complete set of the objects that are termed "sampling units" in statistics. However, the designers of NDT's
tests have often (almost always, so far as I can determine) overlooked the necessity for specifying the
sampling units. In the wake of this omission, people designing associated research protocols have sometimes obscured the inconsistencies that this causes through redefinitions of what "sample" usually means in statistics.

In particular, a single, arbitrarily selected chunk of material is not an example of what one means by "sample" in statistics. Neither is a set of arbitrarily selected chunks of material. A discontinuity is not necessarily an element of what one means by "sample," though it might be. The term "specs obtained with a sliding probe, especially if you want to calculate the false alarms...
: What is "location with discontinuity" and a "location without" do you calculate with smaples of 1 mm in length, or in samples with length of probe diameter (as the active area) or how do you define a sample location... is it only a test specimen?
: For a good calculation of a false alarm rate you need a high number of samples without discontinuities... a very expensive situation, if you declare only a complete testspecimen to be "one" sample...
: Hope I have put the situation in correct words as I am not a "native english speaking expert in statistics", so some expressions used in german for this topic can't be easily retrived from regular dictionaries (I mostly use http://dict.leo.org - a very good living project of the univ. of Munich), sometimes it is hard for us to hit the definition 100%.
: Conclusion: I like this discussion you did, very much and maybe it gives us some additional ideas to improve our work to the benefit of safety
:
: --
: This message was posted into the NDT.net Forum.
: http://www.ndt.net/wshop/forum/forum-2.htm
: Please do not reply to email: forum@ndt.net
: For your reply to this message go to:
------------ End Original Message ------------




    
 
 

Product Spotlight

Exertus Dual 120

The Exertus Dual 120 Projector has the ability to accept Iridium 192 sources or Selenium 75 source
...
s. This projector incorporates design and safety features that make it flexible, compact and lightweight. The Projector is lighter than most of its competitors. It incorporates an improved source channel, based on a new helicoidal design, which makes maintenance easier. The helicoidal design also allows smoother movement of the source assembly inside the device, making it easier for the operator and improving safety. The Projector also has a unique safety feature not found in competitive products. The source assembly locking mechanism is triggered by the source holder capsule at the front of the source assembly, thereby always assuring the operator that the source has returned to the safe position. The Exertus Dual 120 is ISO3999:2004 compliant.
>

CIVA 2017 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.
>

Navic - Steerable Modular Automated Scanner

The Navic is a modular, motorized, steerable scanner designed to carry multiple attachments used
...
in various scanning and inspection applications. The Navic is capable of weld scanning (girth welds and long seam welds), automated corrosion mapping, and tank scanning.
>

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.
>

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
s