Ultrasonic Testing Level 1: What It Is and How to Get Certified

Ultrasonic testing Level 1 is the first certified grade of UT technician. In the US it is usually granted by the employer under ASNT's SNT-TC-1A, whose 2024 edition, as published summaries report it, recommends 40 hours of UT training, 210 hours of UT experience and 400 hours of total NDT experience before certification.

ASNT itself does not issue a Level I certificate under SNT-TC-1A. The employer examines the person and signs the certification under its own written practice. Central schemes built on ISO 9712 work differently, and rail flaw detection adds a separate federal rule, 49 CFR 213.238, that has no levels at all.

In this guide: what a Level I does · the US schemes (SNT-TC-1A and CP-189) · central schemes (ISO 9712 and ASNT 9712) · aerospace (NAS 410 and EN 4179) · rail (213.238) · comparison table · exams and vision · recertification · the written practice · worked example · limits · FAQ

What is ultrasonic testing Level 1?

Ultrasonic testing Level 1 is a certification grade, not a test technique. It says a person has the training, experience and exam results to perform specific UT tasks to written instructions while a Level II or Level III supervises them.

Every major scheme uses the same ladder: trainee, Level I (or Level 1), Level II and Level III. A trainee isn't certified and works only under direct supervision. A Level II interprets results against the code, and a Level III approves procedures and runs the certification program.

The UT method doesn't change with the level; a Level I uses the same flaw detector, probes and reference blocks as a Level II. For the physics, see how ultrasonic testing works and the types of ultrasonic testing in NDT.

Key takeaway: the level describes authority and supervision, not a different kind of UT.

What can a UT Level I do, and what can't they do?

Under SNT-TC-1A, a Level I performs specific calibrations, specific tests and specific accept-or-reject evaluations according to written instructions, records the results, and works under the instruction and supervision of a certified Level II or III. This wording is how published summaries and secondary quotations give the definition; the 2024 text reportedly says "standardizations" where older editions said "calibrations".

A common claim is that a Level I can never make an acceptance call. SNT-TC-1A doesn't say that. A Level I may accept or reject against criteria already written into the instruction, such as "reject any indication above the reference line", but interpreting results against a code or specification is Level II work.

ISO 9712 draws the line a little differently. Certification-body documents based on it say a Level 1 may set up the equipment, perform the test, record and classify results against written criteria, and report them, but is not responsible for choosing the method or technique or for interpreting the results.

The employer's written practice can narrow any of these; it may, for example, bar a Level I from signing the final report.

Key takeaway: a Level I under SNT-TC-1A may make specific accept/reject calls to written instructions, but interpretation against a code belongs to the Level II.

Who certifies UT Level 1 in the US?

In the US, the employer certifies UT Level I, normally under ASNT's SNT-TC-1A or ANSI/ASNT CP-189. Neither ASNT nor any federal agency issues a UT Level I certificate under these documents.

ASNT's standards page describes the two documents this way:

SNT-TC-1A: "Employer guidance for in-house NDT personnel qualification and certification programs, outlining recommended education, training, and experience by method." CP-189: "Establishes minimum requirements for employer-based NDT personnel certification, building on SNT-TC-1A." (ASNT, Standards and Publications)

Both are employer-based. The difference is how binding they are.

SNT-TC-1A is a recommended practice

SNT-TC-1A recommends; it doesn't require. The employer adopts it through a written practice, and that is the document an auditor holds you to.

Which edition applies: the current edition is 2024, followed by errata, a May 2025 addendum and a nonmandatory Appendix C. HSB's December 2025 Pressure Points newsletter reports that ASME accepted SNT-TC-1A-2024 for the 2025 Section V, and that a Section V interpretation requires the written practice to meet the errata but not the addendum.

CP-189 is a standard

CP-189 is an ANSI-accredited standard written in "shall" language, so an employer can't lower its minimums. ASNT says it "Covers certification of Level I, Level II, and Level III personnel, including instructor requirements". Secondary sources add that it requires the employer's Level III to hold an ASNT NDT Level III certificate, where SNT-TC-1A lets the employer examine its own Level III; check the standard before relying on that point.

CP-189's UT hour figures were not confirmed from a public source for this article, so check the 2024 standard itself. For the full SNT-TC-1A structure, see our guide to SNT-TC-1A requirements for NDT certification.

Key takeaway: SNT-TC-1A and CP-189 are both employer certification; ASNT publishes them but doesn't certify the technician.

How many hours does UT Level I need under SNT-TC-1A?

Published summaries of SNT-TC-1A 2024, Table 6.3.1A, give 40 training hours, 210 hours of UT experience and 400 hours of total NDT experience for UT Level I. For Level II they give a further 40 training hours, 630 UT hours and 1,200 total NDT hours.

These figures come from training providers and study guides, not the licensed text, so check them against your own written practice.

The hours aren't split into "classroom" and "practical" bands. The total NDT column means NDT work in any method, so a trainee's MT and PT hours count toward the total but not toward the UT column.

Key takeaway: for UT Level I, plan on roughly 40 training hours and 400 hours of logged NDT work, at least 210 of them in UT.

How do central schemes like ISO 9712 and ASNT 9712 work?

Under a central scheme, an independent certification body examines the candidate and issues the certificate, so the credential travels with the person instead of staying with the employer. ISO 9712 is the international standard for these schemes; the current edition is ISO 9712:2021.

National schemes apply it: PCN, run by BINDT, in the UK; the Natural Resources Canada program under CAN/CGSB-48.9712 in Canada; and ASNT 9712 in the US.

ISO 9712 hours for UT Level 1

ISO 9712:2021 states training and experience in days. Natural Resources Canada's program lists 56 hours of UT Level 1 training and 70 more for Level 2 (126 hours for direct entry to Level 2). It lists 45 days (315 hours) of UT Level 1 experience and 180 days (1,260 hours) for Level 2 combined. ASNT's own Level II page gives the same 18 days of training and 180 days of experience for UT and says one day is at least seven hours.

That is 56 Level 1 training hours against SNT-TC-1A's 40.

ASNT 9712 replaced the ACCP

ASNT says "The ASNT 9712 Certification Program has replaced the ASNT Central Certification Program (ACCP)", and an August 2026 ASNT article says the last active ACCP certifications expire in 2029.

ASNT 9712 offers UT at Level II and Level III only, so there is no ASNT-issued UT Level 1. It sets passing scores of 70% on written and 80% on practical exams, requires a Jaeger J1 near-vision check, and renews every five years.

Key takeaway: ISO 9712 gives a portable certificate, but in the US the central route starts at Level II.

What about aerospace (NAS 410 and EN 4179)?

Aerospace NDT staff are qualified and certified under NAS 410 in the US and EN 4179 in Europe, both employer-based. NAS 410 reaches a supplier through the aerospace customer's contract.

NAS 410 is an Aerospace Industries Association (AIA) standard. AIA's March 2022 standards mailing lists it at Revision 5 with Amendment 2. EN 4179 is its European counterpart; the current edition is EN 4179:2026, valid from February 16, 2026, per a national catalog listing.

Published sources disagree on NAS 410's UT Level 1 hours: training providers agree on 40 training hours, but quote experience figures of both 200 and 400 hours, so check the standard. Secondary sources also report a five-year recertification interval and an annual near-vision exam.

Key takeaway: if a contract names NAS 410, an SNT-TC-1A certification doesn't automatically satisfy it; requalify to the NAS 410 written practice.

How does rail flaw detection qualification under 213.238 differ?

49 CFR 213.238 qualifies operators of rail flaw detection equipment through the employer's own training program, and it uses no Level I, II or III grades. FRA doesn't certify UT technicians, and the rule doesn't mention SNT-TC-1A.

The rule's first paragraph puts the duty on the provider:

"Each provider of rail flaw detection shall have a documented training program in place and shall identify the types of rail flaw detection equipment for which each equipment operator it employs has received training and is qualified." (49 CFR 213.238(a))

A qualified operator is authorized in writing to do four things: conduct a valid search with the equipment they're qualified on, confirm the equipment is performing as intended, interpret equipment responses and act on them, and judge whether the search was compromised. Before initial qualification, the operator needs at least 160 hours of rail flaw detection experience under a qualified operator or the equipment manufacturer's representative, and must show proficiency for each type of equipment. Reevaluation follows the employer's program; the rule sets no fixed interval.

Duty (3) is to "Interpret equipment responses and institute appropriate action in accordance with the employer's procedures and instructions." That is interpretation, which SNT-TC-1A gives to Level II. A UT Level I certificate doesn't qualify anyone under 213.238, and a 213.238 qualification doesn't make anyone a UT Level I.

Key takeaway: rail operator qualification is a separate, equipment-specific employer qualification; it runs beside SNT-TC-1A, not through it.

How do the UT Level 1 schemes compare?

The five schemes a US reader is likely to meet differ in who certifies, whether levels exist, and how long a certificate lasts. Check the edition your contract names.

Key takeaway: in US industry, the scheme is usually set by the contract or code, and the employer's written practice is the controlling document.

What exams and vision checks does UT Level I involve?

Under SNT-TC-1A, a UT Level I candidate passes a general exam, a specific exam and a practical exam, plus a vision examination. Published summaries of the 2024 edition give at least 70% on each written exam, at least 80% on the practical, and a composite average of at least 80%.

• General exam: closed-book questions on UT principles, such as sound velocity, wave modes, and what the A-scan shows.
• Specific exam: questions on the employer's own procedures, codes, equipment and acceptance instructions.
• Practical exam: a hands-on test on at least one flawed specimen, scored against a checklist (summaries say at least ten checkpoints).

Our guide on how to read a flaw detector covers the A-scan, gates and sound-path readouts that the practical will test.

Vision: SNT-TC-1A summaries give an annual near-vision check, Jaeger No. 2 or equivalent at not less than 12 inches, in at least one eye, with or without correction. Color or gray-shade differentiation is also checked; secondary sources disagree on whether that is annual or at certification and every five years, so follow your written practice. ISO 9712 schemes and ASNT 9712 use Jaeger 1, and ISO 9712 scheme forms give a distance of not less than 30 cm.

Key takeaway: passing a training course isn't certification; the employer's general, specific and practical exams, and a current vision check, are.

How long does UT Level 1 certification last?

SNT-TC-1A recommends a maximum recertification interval of five years for Level I and II; ISO 9712 certificates are valid for five years, then renewed, then recertified.

Certification under SNT-TC-1A or CP-189 also ends when the person leaves the employer, because it belongs to the employer's program. The near-vision check runs on its own annual clock inside the certification period.

Key takeaway: count on a five-year cycle at most, with an annual eye exam inside it.

What role does the written practice play?

The written practice is the employer's own document that says how its NDT staff are trained, examined, certified and recertified, and it is what an auditor checks. SNT-TC-1A is the guidance; the written practice is the program.

The employer's Level III normally writes or reviews it and approves it. For UT it sets the levels and what each may do (including who signs reports), the training and experience hours, the exams and passing grades, the vision requirements, the recertification interval, who administers exams, and how records are kept.

Because the written practice controls, two companies can both "follow SNT-TC-1A" and still certify differently. When you hire or subcontract UT, ask for the written practice and the certification records, not just a wallet card.

Key takeaway: the written practice decides the details, including whether a Level I may sign a report.

Worked example: a new hire's path to UT Level I and then Level II

A new technician who logs 40 hours of NDT a week, 24 of them in UT, meets SNT-TC-1A's Level I experience in 10 weeks and Level II's in 40 weeks. Here is the arithmetic, using the 2024 figures as summarized above and assuming the employer's written practice adopts them unchanged.

Inputs: a high-school graduate joins a fabrication shop's NDT department. Each week they log 40 hours of NDT work under supervision: 24 hours of UT and 16 hours of MT and PT. They take a 40-hour UT Level I course in week 1 and a 40-hour Level II course later. The hire's vision passes the annual Jaeger No. 2 check.

Step 1: Level I experience

• UT hours needed: 210. At 24 h a week, 210 ÷ 24 = 8.75, so the UT column is met in week 9 (9 × 24 = 216 h).
• Total NDT hours needed: 400. At 40 h a week, 400 ÷ 40 = 10, so the total column is met in week 10.
• The later of the two governs: week 10. At that point the log shows 240 UT hours and 400 total NDT hours.

Step 2: Level I exams

The candidate scores 78% on the general exam, 82% on the specific exam and 88% on the practical. Each written score is above 70% and the practical is above 80%. The composite is (78 + 82 + 88) ÷ 3 = 248 ÷ 3 = 82.7%, above 80%, so the employer certifies the hire as UT Level I.

Step 3: Level II experience

The Level II figures are cumulative, so the hire keeps counting from day one:

• UT hours needed: 210 + 630 = 840. 840 ÷ 24 = 35, so the UT column is met in week 35.
• Total NDT hours needed: 400 + 1,200 = 1,600. 1,600 ÷ 40 = 40, so the total column is met in week 40.
• The later governs: week 40, with 960 UT hours and 1,600 total NDT hours logged. Training totals 40 + 40 = 80 hours.

Adding the two training weeks, the hire is eligible to sit Level II exams after about 42 working weeks, roughly ten months of full-time work. The total-NDT column, not the UT column, set the pace both times; a hire doing only UT (40 UT hours a week) would reach Level II on the same week 40, because 1,600 total hours is still the binding figure.

The same hire under ISO 9712 and 213.238

If only the UT hours count toward ISO 9712's in-method experience, the 315 hours for Level 1 take 315 ÷ 24 = 13.1 weeks, so week 14, and the 1,260 hours for Level 2 take 1,260 ÷ 24 = 52.5 weeks, so week 53. Training is also longer: 56 hours for Level 1 and 126 for Level 2.

If the employer later moves this technician onto a rail flaw detection cart, 213.238 adds its own step: the provider's training program for that equipment type, at least 160 hours of supervised experience on rail flaw detection, a recorded proficiency demonstration, and written authorization. At 40 hours a week on the cart, 160 ÷ 40 = 4 weeks. Whether earlier UT hours count toward the 160 is for the provider's program to decide; the rule asks for rail flaw detection experience.

Key takeaway: in this example, total NDT hours, not UT hours or training, set the pace from trainee to Level II. For what changes in the work at that point, see our guide to ultrasonic testing Level 2.

What does UT Level 1 certification not cover?

A UT Level I certificate doesn't authorize code interpretation, doesn't travel between employers, and doesn't qualify anyone under 213.238 or NAS 410.

• It isn't portable. SNT-TC-1A and CP-189 certification belongs to the employer's program and ends when the person leaves. A new employer may accept prior records but must certify again.
• It isn't a license. No US federal agency licenses UT technicians. FRA doesn't certify them; it requires qualified operators under 213.238.
• It covers one method. UT Level I says nothing about MT, PT or RT. See the comparison of non-destructive testing methods for what each method does.
• It may not cover every UT technique. A written practice can treat phased array, TOFD or automated UT as separate techniques with their own training and exams. PAUT hour tables were not verified for this article.
• It doesn't make the holder the acceptance authority. On AWS D1.1 or ASME work, the code and the contract decide who accepts the weld. A Level I's accept/reject calls are limited to the written instruction.

Key takeaway: treat UT Level I as entry-level authority within one employer's program, not a general credential.

How EMA Industries applies this

EMA Industries offers NDT Level III services alongside ultrasonic rail flaw testing, rail weld inspection, AWS D1.1 structural weld UT, MT and PT, and WPS/PQR work. We're based in Southern California and mobilize nationwide. A Level III can review whether a written practice, its UT hour tables, exams and vision records match the edition of SNT-TC-1A or CP-189 your contract names, and on rail work, whether operator qualification records also meet 213.238. To scope Level III support or UT inspection, see our ultrasonic examination services or contact us.

Related reading: SNT-TC-1A requirements · Ultrasonic testing Level 2 · Types of ultrasonic testing in NDT · How to read a flaw detector

Frequently asked questions

Can I get UT Level 1 certified on my own, without an employer?

Not under SNT-TC-1A or CP-189, because the employer is the certifying body. You can complete the training hours on your own, but certification needs the employer's written practice, exams and Level III. ISO 9712 schemes such as PCN do certify individuals, but ASNT 9712 offers UT only at Level II and III.

How long does it take to become a UT Level I?

Under the SNT-TC-1A 2024 figures, it takes about 40 hours of training plus 400 hours of NDT experience, at least 210 of them in UT. That is about 10 to 11 weeks of full-time NDT work. Your employer's written practice can set longer requirements.

Does ASNT issue UT Level I certificates?

ASNT doesn't issue Level I or Level II certificates under SNT-TC-1A. It publishes SNT-TC-1A and CP-189, and it runs ASNT 9712, the ISO 9712 program that replaced the ACCP, which certifies UT at Level II and Level III. A UT Level I in the US is an employer certification.

Can a UT Level I accept or reject a part?

A UT Level I can do so only as a specific evaluation that follows written instructions. SNT-TC-1A lets a Level I make specific accept/reject determinations against criteria in the instruction. Interpreting results against a code or specification is Level II work, and the written practice may restrict Level I further.

Is a UT Level I qualified to test rail under FRA rules?

Not by that certificate alone. 49 CFR 213.238 requires the provider's documented training program, at least 160 hours of supervised rail flaw detection experience, proficiency on each equipment type, and written authorization. It uses no Level I or II grades.

Sources

• 49 CFR 213.238, Qualified operator, eCFR; text read on Cornell LII, October 2026
• ASNT Standards and Publications: SNT-TC-1A (2024, with Addendum) and ANSI/ASNT CP-189 (2024), ASNT
• ASNT 9712 Level II requirements, ASNT Certification
• Understanding ASNT 9712, P. Lang, ASNT, August 1, 2026
• Don't miss out on ASME Code errata and notices, A. Garbolevsky, HSB Pressure Points, December 2025
• Training requirements and prerequisites for NDT certification, Natural Resources Canada (CAN/CGSB-48.9712)
• Qualifying work experience for NDT certification, Natural Resources Canada
• NASC standards mailing, March 10, 2022 (NAS 410 Rev. 5, Amd. 2), Aerospace Industries Association
• EVS-EN 4179:2026 catalog listing, Estonian Centre for Standardisation
• SNT-TC-1A guide (2024 edition summary), Trace NDT (secondary; training provider)