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December 2015 / January / February 2016 : The Laws of chance

Written by Dubosc
Tuesday, 24 November 2015 22:33

In the '90s, a marine engines manufacturer/MRO (maintenance, repair and overhaul) purchased a complete set of MT equipment. Among different devices, a digital tangential magnetic-field meter was supplied.

After close to two years in-service, both the Hall probe and its cable were damaged; the tangential magnetic -field meter was unusable.

A new probe-and-cable set was due, and the entire unit would need a recalibration.

As a matter of fact, when a sensor/probe and/or a cable (except for the mains-to-meter cable, if any) of a tangential magnetic-field meter is changed, the entire unit shall be recalibrated. This is valid for magnetic-field meters as well as for radiometers/luxmeters, just to stay in our PT/MT NDT methods.

This meter was, then sent back to the supplier which happened not to be certified according to the ISO 9001-1994 standard, in force at that time. This company had no qualification either to repair or calibrate it. This supplier sent back the unit to its own supplier along with a request to quote for repair and recalibration.

This supplier was also only a middleman! The meter went finally to the manufacturer.

When receiving the quotation, the user gave its OK.

After a (long!) while, the user got back his meter with the invoice and the recalibration certificate.

When opening the parcel, he saw that the cable had not been replaced, but only patched up with some adhesive tape! How reliable could, then the calibration be?

If only the last supplier had had a look at the meter! He would have seen the problem, would have gone back to the origins and his customer would not have been unhappy about a botched repair!

After a thorough search, it was obvious that the meter was no longer manufactured and that no spare probe was available. Though the user had bought the equipment only two years before! You may think that he disliked his relationship with the supplier.

Almost simultaneously, this same customer ordered UV-blocking glasses from the same supplier. He got clear glasses, when a lot of people thought, then that glasses had to be yellow so as to block UV-A radiation. A misunderstanding atop a steep invoice (once again, several middlemen led to kind of a domino effect as each one made a profit). Due to his bad example with the meter, the customer did not pay.

This final supplier knew nothing about NDT. His job was to supply many items products for industrial uses. The NDT world is a specific one, and it is better - and quite often cheaper! - to work with renowned companies established in this field since a long time!

Normative Reference

ISO 9001:1994 Quality systems -- Model for quality assurance in design, development, production, installation and servicing, International Organization for Standardization, Geneva, Switzerland, 1994.

In the '60s, a UK Company had a motto: ‘‘for every surface treatment problem, there is a product xxxxxx" (trademark we do not display).’’

Engineers and Commercial people in this Company had made a "translation": ‘‘with every surface treatment product xxxxxx (trademark we do not display), there is a problem.’’

This anecdote is there only to remind everyone that problems met in workshops may be due to the suppliers/manufacturers as well as to the users.

Our idea in these documents is NOT to target anyone, but on the contrary to bring to your knowledge some interesting cases which may prevent you to duplicate the same mistakes while performing Penetrant Testing (PT) or Magnetic Particle Testing (MT).

All the ministories you will read are TRUE. We think they will be helpful:

  • First as examples of specific technical - or non-technical - requirements or peculiar problems.
  • Second to let you see that the problems do not always come where you think they should come from.
  • - Third so that users feel free to ask for help from people (the experts) who may know more than they do.

If you know of examples of some interest for others, please feel free to mail them to us. They will be displayed on our website as anonymously as those already published.

One's experience may help others. In addition, any interesting problem met during audits may also help: auditors, who sometimes face incredible situations and have hard times, as well as auditees may have very useful pieces of information.

We thank you in advance for any input.

Last Updated ( Wednesday, 25 November 2015 08:23 )