Non Destructive Testing
NDT, Non-Destructive Testing or NDE for Non-Destructive Evaluation is a procedure to examine and determine an objects integrity and physical composition without dismantling or destroying it. Non Destructive Testing is an industry with many sub-genres and branches into everything from manufacturing and production with it's role in quality control and quality assurance, to maintenance and material analysis with an entire scope of different solutions and products used for any given task at hand.
Terms such as ultrasound and ultrasonic testing, flaw detection, crack detection, endoscopes, videoscopes, gauges and testers among many more can be found in the NDT industry. It can be a jungle to navigate.
Here you will find an archive of explanations and definitions of common terms and applications used in the NDT and inspection industry.
What is Quality Control?
The development of the Non-Destructive Testing methods started many years ago, as it became common practice to join materials together by welding, a need for quality control of the welding-seams arised.
Non-destructive testingmethods such as X-ray (Radiography), ultrasound/ultrasonic transducing, liquid penetrant powder solutions (capillary liquids), magnetic powder solutions, saw it's first use in detecting flaws and errors, made during- or as a result of- the manufacturing processes in the early days of the industrial revolution. All of these methods are commonly known under one term: NDT - Non-Destructive Testing.
Later on, as the requirements in Quality Control got more strict and became more specified and detailed, the accept or discard criterias has ended up welldefined with regional or worldwide standards for any given method.
What is Condition Monitoring?
Condition Monitoring, or Condition Audit relies on knowledge about material degradation processes, which in any given environment and for any given material in different constructions, decides what inspection and/or monitoring method is applied for optimum effect.
Furthermore, the standards on which to base accept or discard criteria is rarely well defined in condition monitoring as it is dependant on construction, type- and amount of degradation and the production circumstances involved in each case.
Discard criterias will in many cases be determined on a basis of several parametres which must be identified using several methods combined.
When it comes to maintenance and condition monitoring, it is not possible to decide methods or define accept and discard criterias before you have operational and material based knowledge, on what kind of degradation will occur and what effects it will incur in the materials used.
This also means that during Condition- or Component Monitoring, it is only possible to standardize procedures for the Non-Destructive Methods when it comes to certain types of material/component failures, while method decision and accept/discard criterias in most cases cannot be standardized.