The Nondestructive Testing (NDT) field is currently flourishing; the international market is projected to hit $21.2 billion by 2025. As the industry continues to grow, so will the demand for certified NDT technicians who are competent and able to meet the demands of nondestructive testing.
In order to earn an official certification, prospective NDT technicians must be able to prove that they have completed the required training and education that is specific to their certification level and examination method. Certifications provide that proof to potential employers and assure them that their NDT technicians are qualified to work for their company.
NDT certifications, explained
Although the certification exams for each of the three NDT levels come with different requirements and cover different material, depending on the examination method being studied, all three certifications require potential technicians to pass three written exams, earn a specified number of training hours and meet the minimum requirements for a vision test.
The written exams for Level I and Level II technicians are very similar. All candidates must pass a general exam, which covers the general principles of the NDT method they choose to specialize in, a specific exam, which covers techniques, equipment and procedures specific to their employer and a practical exam, in which the technician is given a part as an example and must inspect that part according to their inspection method.
Similarly, Level III technicians must also pass three written exams. Level IIIs must take a basic exam, which covers general NDT techniques and equipment, a method exam, which covers applied techniques and methods and a specific exam, which covers techniques, methods and equipment for a specific product.
To qualify for the Level III exam, NDT technicians must obtain the number of training hours required for their preferred inspection method, which can be completed through colleges, vocational or technical schools, the Armed Forces or training companies. Candidates for ASNT certification, for instance, are expected to score at least a 70 on each individual exam and an 80 composite score. This also goes for Industry Sector Qualification (ISQ) certifications from ASNT, a relatively new cert meant specifically for oil & gas NDT jobs.
NDT certification requirements for each method
When the stress within a material is redistributed, the movement sets off stress waves; the generation of these waves is called acoustic emission. Acoustic emission, or AE, may be set off by earthquakes or rockbursts, or smaller events like cracking, fiber breakage or melting within a material.
AE is the only NDT examination method that requires the same number of training hours for Level Is and Level IIs that only have a high school diploma or equivalent. Both levels are expected to have at least 40 hours of on-the-job training, although Level IIs are required to have more work experience.
Those that have at least two years of higher education must complete at least 32 training hours for a Level I certification or 40 hours for a Level II certification.
The three forms of electromagnetic testing (ET) – Eddy Current testing, Alternate Current Field Measurement and Remote Field testing – all use electric currents or magnetic fields to measure the thickness and conductivity of a material and to check for cracking.
Technicians looking to become certified in ET must have a basic understanding of physics as the certification exams cover topics such as the properties of electricity, Ohm’s Law, induction and circuits. Exams will also cover procedures and equipment for all three types of ET.
Potential technicians who have earned a high school diploma or equivalent must complete at least 40 hours of training for a Level I certification or 80 hours of training for a Level II certification. When a technician has completed at least two years of higher education, the training hours change to 24 hours for a Level I and 40 hours for a Level II.
Liquid penetrant testing (PT) uses a low viscosity liquid to check for any cracks or voids on the surface of a piece of equipment. The penetrant liquids used may be visible, or seen in ambient light, or fluorescent, meaning they must be seen under a blacklight.
The certification exam for PT covers all three testing techniques, including Solvent Removable penetrants (must be removed with a solvent other than water), water-washable penetrants and post-emulsifiable penetrants (must be removed with an emulsifier).
Liquid penetrant testing has the lowest number of required training hours of all inspection methods for technicians who have completed at least two years of post-high school education. Both Level I and Level II technicians only need four total training hours, although that number goes up to 16 hours for a Level I and 32 hours for a Level II if the technicians only have a high school diploma.
Although magnetic particle testing (MT) is technically a form of electromagnetic testing due to its use of magnetic fields to locate surface and near-surface issues, it is also one of the most widely used NDT inspection methods, and is therefore considered a stand-alone method.
Compared to the ET certification exam, the MT exam requires less training hours from potential technicians. Those with a high school diploma or equivalent need 16 hours of training to become a Level I technician and 32 hours for a level II, while those who have completed higher education need eight hours to become a Level I and only four hours to become a Level II.
The four types of radiography testing (RT) – film radiography, computed radiography, computed tomography and digital radiography – all use radiation to inspect an object. The radiation passes through the material to a receiving medium on the other side, which shows the amount of radiation that was able to pass through the object.
Radiography has one of the highest numbers of required training hours for technicians with a high school diploma. Level I technicians will need 40 hours of training, while Level II technicians need 80 hours. If the technician has completed some form of higher education, they will need 30 hours to become Level I certified and 35 hours to become Level II certified. In addition, NDTs must get the radiation safety (IRRSP) certification to qualify for radiographer positions.
The thermal/infrared (IR) methods of NDT use infrared radiation in a similar way that the radiography method uses radiation. IR passes heat through, to or from an object, then measures the amount of infrared radiation that the object gives off.
Potential NDT technicians that would like to specialize in IR need to complete at least 32 hours of training to reach a Level I or 34 hours to reach a Level II if they have a high school diploma or equivalent. Those that have completed at least two years of higher education will need 30 hours to reach a Level I or 32 hours to reach a Level II.
Ultrasonic testing (UT) is considered to be one of the most versatile NDT methods. It uses high-frequency sound energy to look for imperfections in materials. It can detect flaws on or below the surface of objects, it is highly accurate and provides instantaneous results. The depth of its penetration when examining an object is much better than other inspection methods. Ultrasonic testing requires a deep understanding and knowledge of Phased Array Ultrasonic Testing (PAUT) and Time-of-Flight Diffraction (TOFD) flaw-detection procedures, as well as how to measure UT thickness.
Like radiography testing, UT has one of the highest numbers of required training hours out of all NDT methods. Technicians with a high school diploma require the same hours as RT; Level Is need 40 hours and Level IIs need 80 hours. When the technician has completed post-high school education, the hours required go to 30 for a Level I and 40 for a Level II.
When using vibration analysis (VA), technicians analyze the vibration signatures emitted by a piece of rotating machinery. The vibration signatures provide information about the condition of a piece of equipment.
VA requires all potential Level I technicians to complete 24 hours of training, regardless of their level of education. Level II technicians will need at least 72 hours if they have a high school diploma or equivalent or at least 48 hours if they have completed two or more years of study in science or engineering after high school.
Possibly the simplest examination method (and by far the most popular) is visual testing, or VT. Technicians simply need to look at an object to measure any flaws or inconsistencies with their eyes; no additional equipment is needed, although the technicians may use things like magnifying glasses or mirrors to enhance their vision.
Because VT does not require much training on specific pieces of examination equipment, potential technicians do not need as many training hours as they would with most other NDT methods. However, most visual testing positions demand the use of remote visual inspection tools such as video technology (videoscopes, push cameras, fiberscopes), and so training on those devices is highly encouraged.
Potential VT specialists that have a high school diploma or equivalent only need eight hours of training to reach a Level I and 16 hours to reach a Level II. Those with post-high school education will need four hours to reach a Level I or eight hours to reach a Level II.
One thing to consider is that ASNT has an agreement with the American Welding Society (AWS) to allow CWIs and senior CWIs (SCWIs) access to VT certification through the ACCP CWI/SCWI Certification Program. Through this arrangement, CWIs have a fast track gaining a specialization in visual testing.
Preparing for a job in NDT may seem intense, but Surehand wants to make the process easier. Certified candidates can create an online profile on the Surehand website, then sit back and let potential employers come to them. No more job hunting, no more pressure.