UT Level I in Wichita: What the Level Permits and How You Reach It
A UT Level I performs calibrations and specific ultrasonic tests to a written procedure, records results and reports them to a Level II or III, but does not independently evaluate or accept the part. SNT-TC-1A recommends 40 hours of UT training and 210 hours of method experience; the employer's written practice sets the binding figures and the scope.
Wichita's demand for ultrasonic work is unusual because it is dominated by aerospace rather than energy. The city is the historic Air Capital: Textron Aviation builds Cessna and Beechcraft airframes here, the aerostructures plant that builds Boeing 737 fuselages was folded back into Boeing in 2025, and Bombardier runs a defence and service-centre operation on the former Learjet campus. That base pulls UT toward wrought aluminium plate and forgings, bonded and composite structure, and titanium billet, qualified under NAS 410 and audited to Nadcap AC7114. Around it sits a second economy: tank and vessel fabrication, agricultural and grain-handling equipment, structural steel, and Kansas oilfield and gas-processing service work. A Wichita Level I therefore learns two dialects of the same method, aerospace immersion and contact scanning against reference standards, and industrial thickness surveys on carbon steel, and the written practice decides which one the certificate covers.
Source: Written to ASNT SNT-TC-1A (2020 edition), ANSI/ASNT CP-189, ISO 9712:2021 with ISO/TS 25107 training syllabi, NAS 410 and Nadcap AC7114, AMS-STD-2154 for ultrasonic inspection of wrought metals, ASTM E797 for thickness measurement by contact ultrasonics, ASTM E2375 for wrought products, ASME Boiler and Pressure Vessel Code Section V Article 4, ASME B31.3 and AWS D1.1.
| Element | ASNT SNT-TC-1A (2020) | ISO 9712 | What decides in practice |
|---|---|---|---|
| Formal training | 40 hours of organised UT training recommended for Level I | Training to the ISO/TS 25107 Level 1 UT syllabus | The employer's written practice, or the certification body's approved scheme |
| Experience | 210 hours in the method, 400 total NDT hours recommended | Three months of industrial experience in the method | Written practice hours are binding; documented and signed hour logs are the evidence |
| Scope of authority | Specific calibrations, specific tests and specific evaluations to written instructions, with supervision | Works to written instructions under supervision; not responsible for choice of technique or assessment of results | Most employers restrict Level I further than the scheme allows |
| Examinations | General, specific and practical; composite 80 percent minimum, no single exam under 70 percent | General, specific and practical set by the certification body | Specific examination must reflect the employer's own procedures and equipment |
| Vision | Near vision annually (Jaeger No. 1 at 12 in or equivalent) plus colour contrast check | Near vision annually, verified and recorded by the employer | Annual scheduling; the lapsed vision record is the classic audit finding |
| Who issues the certificate | The employer, signed by its certifying Level III | An accredited third-party certification body | Determines whether the certificate travels when you change job |
| Validity | Recertification at intervals not exceeding five years | Five years, renewable, with fuller recertification at ten years | A shorter interval in the written practice always wins |
What a UT Level I is actually authorised to do
The scope of Level I is the most misread thing in the method. SNT-TC-1A defines an NDT Level I as qualified to perform specific calibrations, specific tests and specific evaluations for acceptance or rejection according to written instructions, and to record results, while receiving the necessary instruction or supervision from a certified Level II or III. So a Level I can make an accept or reject call, but only against a written instruction that somebody else wrote, and only across the scope that instruction explicitly covers.
What a Level I does not do is choose. The technique, the probe and wedge, the reference block, the scan plan, the acceptance criterion and the interpretation of anything the instruction did not anticipate all belong to the Level II. ISO 9712 states the boundary more bluntly: Level 1 personnel carry out NDT operations according to written instructions under the supervision of Level 2 or Level 3 personnel, and are not responsible for the choice of test method or technique to be used, nor for the assessment of results.
Competitor training pages get this wrong in both directions. Some assert that a Level I cannot make any accept or reject decision at all, which is stricter than SNT-TC-1A actually is. Others imply that a Level I can inspect independently once certified, which is far looser than either scheme permits. The correct answer sits in the employer's written practice, which is free to be more restrictive than the recommended practice and frequently is. Many Wichita employers limit Level I to data collection and calibration and reserve every disposition for a Level II, and that restriction is entirely legitimate.
Training and experience: the numbers, and who sets them
SNT-TC-1A's 2020 edition recommends 40 hours of organised ultrasonic training for Level I and a further 40 hours for Level II, with experience of 210 hours in the method inside 400 total NDT hours for Level I, rising to 630 hours in method inside 1,200 total NDT hours for Level II. Ultrasonics, radiography and eddy current share that experience table. The surface methods sit far lower, which is exactly why ultrasonic and radiographic technicians take longer to qualify and command more in the market.
Under ISO 9712 the frame is different in shape rather than in severity. Training content follows the ISO/TS 25107 syllabi, and the industrial experience requirement for ultrasonic Level 1 is expressed in months rather than hours: three months of documented experience in the method, with defined credit rules for part-time work and for candidates going directly to Level 2 without certifying at Level 1 first. The experience must still be documented and verified by the employer even though the certificate is issued by an independent body.
In both systems the published hours are a floor and the written practice is the ceiling. If an employer's practice specifies 60 hours of training for UT Level I because its work involves difficult geometry or thin sections, 60 is the number that must appear in the record and 40 is a non-conformance. Where a prime contractor invokes NAS 410, which is routine across Wichita aerospace, that document supplies its own tables and, unlike SNT-TC-1A, it becomes a contractual requirement the moment it lands on the purchase order.
Calibration is the Level I's real job
Almost every Level I task begins with a calibration that somebody else must be able to reproduce. Velocity comes first: longitudinal velocity in steel is roughly 0.2320 inches per microsecond, or 5,920 metres per second, shear about 0.1280 inches per microsecond, and longitudinal velocity in aluminium around 0.2480 inches per microsecond. Getting velocity wrong scales every single reading proportionally, and it is the most common cause of a thickness survey that trends beautifully and is uniformly and confidently wrong.
Zero offset comes second. The delay in the wedge or delay line, the couplant layer and the instrument electronics all sit between the transmitted pulse and the front wall, and a zero offset error adds a constant rather than a proportion. A Level I who understands that distinction can diagnose a bad set-up from the pattern of the errors alone: proportional error means the velocity is wrong, constant error means the zero is wrong, and both together usually mean somebody calibrated on the wrong block or on the wrong material entirely.
Then sensitivity. A distance amplitude correction curve is built empirically by plotting the response from identical reflectors, usually side-drilled holes, at increasing metal path in a reference block, so the material's attenuation and the instrument's characteristics are carried inside the curve. DGS, known in Europe as AVG, does the opposite: it uses a set of published curves specific to the probe, relating distance, gain and equivalent disc reflector size, calibrated from a single reference such as a back wall. DGS demands explicit transfer correction and attenuation input. DAC hides them, but only if the reference block genuinely matches the part.
Couplant, surface and temperature: where Level I readings go wrong
Coupling is a physics problem disguised as a housekeeping one. The couplant fills the acoustic mismatch between the probe or wedge and the part, a thin consistent film is the target, and a thick one adds path length. On rough, scaled or corroded surfaces the loss is real and unpredictable, and it should be quantified with a transfer correction measured on a representative surface rather than compensated by winding the gain up until something appears on the screen. Gain applied without a recorded reason is not a correction, it is a guess.
Temperature shifts velocity. The common working rule for steel is roughly one percent of reading per 100°F of change, so a survey taken on a hot line but calibrated on a cold block reads high unless it is corrected, and the reverse applies to the outdoor winter work that Kansas shops run for months at a stretch. High-temperature couplants and delay lines exist precisely for this, and their temperature and duty limits are procedural constraints rather than suggestions to be worked around when the schedule is tight.
The classic corroded-steel failure is doubling and mode conversion. An instrument working in echo-to-echo mode can lock onto the wrong pair of echoes and report double or half the true wall, and a heavily pitted back wall scatters energy so that the gauge reads whatever returns rather than the true minimum remaining wall. A Level I trained to look at the A-scan rather than the digital readout catches this immediately. One trained only on a thickness gauge does not, which is why every serious survey procedure requires A-scan verification of anomalous readings.
What the examinations actually test
There are three examinations: general, specific and practical. The general covers method principles: wave modes, velocity and acoustic impedance, attenuation, beam spread, near field and far field, transducer construction and damping, and the arithmetic behind calibration and sizing. The specific covers the equipment, procedures, techniques and acceptance criteria of the employer's own work, and a generic paper filed under the specific examination heading remains one of the most frequent audit findings on any certification file.
The practical is where candidates fail. You are given equipment, a calibration block, a written procedure and a specimen, and you are scored against defined checkpoints: did you calibrate correctly and repeatably, did you achieve the required scan coverage, did you find and correctly locate the reflectors, and did you record the instrument settings, block identity, couplant, surface condition and probe serial number. SNT-TC-1A's model asks for a composite grade of at least 80 percent with no individual examination below 70 percent, and complete, legible, reproducible data sheets carry far more marks than most candidates expect.
Wichita's industrial base and what it asks of a UT Level I
Aerospace sets the tone. Wichita's airframe and aerostructures work drives ultrasonic inspection of wrought aluminium plate and forgings, titanium product, and bonded and composite structure, and it does so under NAS 410 personnel requirements with Nadcap AC7114 audits layered over the top. Two things surprise technicians arriving from general industry. Acceptance for wrought product is commonly expressed as a flat-bottom-hole equivalent class under AMS-STD-2154 rather than as a percentage of a DAC curve, and immersion scanning with controlled index and scan speed is a genuinely different discipline from hand scanning a weld.
For composite and bonded structure the useful signal is attenuation and back-wall loss rather than a discrete reflector with a measurable path. A Level I is scanning against reference standards containing engineered defects: flat-bottom holes, implanted films, controlled disbonds at known depths. The reference standard is part of the procedure rather than an accessory to it, and losing traceability of that standard invalidates the data just as completely as losing the calibration record. Aerospace auditors check reference standard control because they know that is where programmes drift.
Around aerospace sits the rest of the Kansas economy: tank and pressure vessel fabrication, agricultural and grain-handling equipment, structural steel work, and oilfield and gas-processing service work across south-central Kansas, with refining capacity at El Dorado roughly thirty miles north-east of the city and further north around McPherson. That work is carbon steel, code-driven, and oriented toward thickness surveys and weld examination, with ASME Section V setting technique, ASME Section VIII or B31.3 setting acceptance, and AWS D1.1 governing structural connections. A Wichita Level I who can work both dialects fluently is unusually employable here.
The written practice, and the certificate that does not travel
Under SNT-TC-1A your certificate is issued by your employer against its written practice and signed by its Level III of record. Leave, and the certificate does not come with you. The next employer must certify you under its own practice, which means its own review of your training and experience and, in almost every case, its own specific and practical examinations on its own procedures and equipment. It may credit your documented history, and usually will, but it must issue its own certification and hold its own records.
This is not a technicality, and it is the reason every technician should keep a personal file. Training certificates, hour logs signed by a supervising Level II, examination results, prior specific examination scope and vision records are what turn a two-week onboarding into a two-day one. ISO 9712 avoids the problem structurally by certifying the individual through an accredited third party, which is why technicians who expect to move between contractors, between states or internationally increasingly carry both an employer certificate and an ISO 9712 one.
Moving from Level I to Level II
Level II is where the work changes character. A Level II sets up and calibrates equipment, interprets and evaluates results against codes, standards and specifications, writes the instructions a Level I follows, exercises the technique and coverage decisions the Level I is not permitted to make, organises and reports results, and provides the on-the-job guidance the recommended practice expects a Level I to receive. The additional training and experience hours are the visible part of the step. The change in responsibility is the real one, and it is what the specific and practical examinations are testing for.
The most useful thing a Level I can do in the meantime is keep a defensible experience log: dates, employer, method, technique, material and product form, thickness range, procedure number and the supervising Level II who can attest to it. Auditors ask for it and so does the next employer. Reconstructing three years of hours from memory on the day a certification decision is due is where perfectly capable careers stall for six months, and it is entirely avoidable with a notebook.
How Atlantis delivers UT Level I for Wichita employers
Atlantis NDT delivers ultrasonic testing training at Levels I, II and III to ASNT SNT-TC-1A and ISO 9712, as classroom, on-site corporate or blended programmes, with the specific examination built around the employer's own procedures, calibration blocks, reference standards and instruments rather than drawn from a generic question bank. For employers working under NAS 410 we map the training content and examination evidence to the tables their prime contractor invokes, so the file reads correctly when a Nadcap auditor opens it.
For employers standing a programme up from nothing, or repairing one after a customer audit, our ASNT Level III consulting covers the written practice itself, the examination bank, the Level III of record function and the personnel record structure. Ask for a consultation or a scoped quote at info@atlantisndt.com. Programmes are built to the employer's scope and product forms rather than sold from a catalogue, and the positioning is affordable, accessible and fully customisable.
What can a UT Level I do without a Level II present?
Set up and calibrate the instrument, perform the specific tests the written instruction covers, record the results, and make accept or reject determinations only where that instruction states the criteria explicitly. The Level I does not select the technique, write the instruction, interpret anything the instruction did not anticipate, or issue the final report. SNT-TC-1A expects the Level I to receive necessary instruction or supervision from a certified Level II or III throughout.
How many training and experience hours does UT Level I require?
SNT-TC-1A's 2020 tables recommend 40 hours of organised ultrasonic training plus 210 hours of experience in the method within 400 total NDT hours for Level I. ISO 9712 expresses the same requirement as three months of documented industrial experience alongside training to the ISO/TS 25107 syllabus. Both are floors. The employer's written practice, or a prime contractor's NAS 410 tables in aerospace, sets the number that actually governs your file.
What is the difference between a DAC curve and DGS, and which does a Level I use?
A DAC curve is built empirically by plotting responses from identical reflectors, usually side-drilled holes, at increasing metal path in a reference block, so material attenuation and instrument behaviour are baked into the curve. DGS, or AVG, uses published probe-specific diagrams relating distance, gain and equivalent disc reflector size, calibrated from a single reference such as a back wall, and requires explicit transfer correction and attenuation input. A Level I sets up whichever the procedure names, exactly as written.
Does Wichita aerospace work require more than SNT-TC-1A certification?
Usually yes. Airframe and aerostructures primes invoke NAS 410, which sets its own training, experience and examination tables and, unlike SNT-TC-1A, is a contractual requirement rather than a recommendation once it appears on the purchase order. Nadcap AC7114 audits then check that the employer actually did what NAS 410 and its own procedures say. Certification remains employer-based, but the evidence bar and the audit exposure are materially higher.
Why do ultrasonic thickness readings change on hot or corroded steel?
Velocity falls as steel heats, so a survey taken hot but calibrated on a cold block reads high; a common rule of thumb is around one percent of reading per 100°F, and high-temperature couplants and delay lines exist to manage it. Corroded surfaces add two more failures: coupling loss on rough scale, and a heavily pitted back wall that scatters energy so the gauge locks onto the wrong echo or doubles. A-scan verification catches both.
Does a UT Level I certificate transfer to a new employer?
Not under SNT-TC-1A. Certification is issued by the employer against its own written practice and signed by its Level III of record, so a new employer must certify you again. It will normally credit documented training hours, a signed experience log and prior examination results, which is why keeping your own file is worth the effort. An ISO 9712 Level 1 certificate belongs to you and travels, though the new employer still authorises your work on its equipment.