A help to choose the most suitable technique

Misconceptions within magnetic testing

February 2012

This document is based on a conference given by George HOPMAN, in Las Vegas, on 13 November 2007.
It is important to know a bit more about this man, well known - and renowned - in the American NDT world. You may find his résumé at the end of this paper.

Time goes by and some things may have changed since this conference. What we wish here is to show "the critical thinking" we all of us shall continuously have: this is not always because one does "according to the relevant standards or documents" that one shall perform a successful inspection, i.e. finding the discontinuities that must be detected.

MT magnetizing techniques

January 2012

We have the pleasure to publish on our Website a contribution by a French MT expert, Stéphane GRAVELEAU, from the R and D Department of SREM TECHNOLOGIES (France).

Magnetizing techniques and current waveforms are described.
Very often, the wave forms displayed in training courses, even in standards, are those got on weakly inductive loads. As this paper explains, on highly inductive loads, the curves do not have the form that one would expect.
In fact, waveforms are very dependent on the electric characteristics of the load.

PT reference test blocks check

December 2011

We have received a very interesting question from a good ol’ friend:

"My question is quite simple: how do we check the modifications (wear) of the test panels used for fluorescent PT?
Do you know of standards or papers (and if so, where can I get them from?), which provide (or allow for the establishing of) a procedure to perform this check? Indeed, according to the PRI (NADCAP) questionnaire, any change in the dimensions of artificial discontinuities shall be less than 30% (further, measured on their longest dimension.) This is for the Tam panel/PSM® 5. However, how should we do for the Type 1 reference test blocks of the ISO 3452-3 standard?

Degreasing prior to penetrant testing

November 2011

1- Introduction

Degreasing prior to PT is an ESSENTIAL and DECISIVE step to ensure a reliable inspection.

In fact, pollutants such as oils and fats, as any other material may clog discontinuities and prevent penetrant to do its job properly. As good as penetrant materials or inspectors are, nothing can be done against.