SNT-TC-1A
ASNT SNT-TC-1A is the recommended practice for personnel qualification and certification in nondestructive testing, defining an employer-based certification model in which the employer issues a written practice and qualifies its own personnel using ASNT-recommended training hours and examinations.
Definition
SNT-TC-1A is the most widely used personnel certification standard in North America. The employer is the certifying agency; certifications are not portable between employers. Contrast with ISO 9712 third-party central certification and with ASNT CP-189.
What this document is
An ASNT recommended practice — explicitly a guideline, not a standard — that an employer uses as the basis for its own Written Practice governing training, experience, examination and certification of its NDT personnel.
How it is applied
Certification is by the employer, against the employer's Written Practice. That makes it flexible and makes verification harder: the meaningful question at audit is not whether someone is certified but whether the Written Practice complies and whether the records demonstrate the individual met it.
Related documents
ASNT SNT-TC-1A as the recommended practice; ANSI/ASNT CP-189 as the standard alternative where a standard rather than a guideline is required; NAS 410 in aerospace.
The common misuse
Citing SNT-TC-1A as though it were a specification. It recommends; the employer's Written Practice is the governing document, and auditors ask for that.
Frequently asked questions
What is the difference between SNT-TC-1A and CP-189?
SNT-TC-1A is a recommended practice the employer adapts in its Written Practice; CP-189 is a standard with fixed requirements and less latitude. Contracts that want consistency across suppliers tend to specify CP-189 or ISO 9712 rather than SNT-TC-1A.
Where SNT-TC-1A fits in an inspection programme
A term is only useful when it connects to a decision. SNT-TC-1A appears in written procedures, in technique sheets, and in the records an owner or accreditation body reviews afterwards — which means the way it is defined in your documentation has to match the way it is applied on site. Where the two drift apart, audits find it. Atlantis writes and reviews procedures against the governing codes, trains inspection personnel to apply them, and builds the record-keeping that makes the evidence retrievable years later. Procedure development and code consulting · NDT training and certification · Ask us about your programme.
Related terms
- ASNT CP-189 — ASNT CP-189 is the standard for qualification and certification of NDT personnel that mandates (rather than recommends) requirements — including a minimum 30-question general examination from an ASNT-furnished question pool — making it the most rigorous employ
- ISO 9712 NDT Personnel Qualification — ISO 9712 is the international standard for qualification and certification of NDT personnel, defining a third-party central-certification model in which an accredited body conducts written and practical examinations independent of the employer.
- NDT Level I — An NDT Level I is qualified to perform specific calibrations, conduct specific NDT examinations following written procedures, and record results, but is not authorized to set up tests, interpret results for accept/reject, or report results without Level II/III
- NDT Level II — An NDT Level II is qualified to set up and calibrate equipment, conduct examinations to procedures, interpret and evaluate results against acceptance criteria, and report results — the standard certification level for production inspectors.
- NDT Level III — An NDT Level III is qualified to develop and approve procedures, establish techniques, interpret codes and specifications, designate methods to be used, train and examine Level I and II personnel, and assume technical responsibility for the NDT facility.
- Written Practice — A written practice is an employer-issued documented procedure required by SNT-TC-1A and CP-189 that defines training, experience, examination, and recertification requirements specific to that employer for each NDT method and level.
Further reading
asnt snt tc 1a vs cp 189 comparison · asnt snt tc 1a certification requirements
More standard terms
ASME Section V · ASME Section VIII · ASME Section IX · ASME Section XI · ASME B31.1 Power Piping · ASME B31.3 Process Piping · ASME B31.8 Gas Transmission and Distribution Piping · ASME B31.4 Liquid Pipelines · API 510 Pressure Vessel Inspection Code · API 570 Piping Inspection Code
Where this comes up in practice
Terms like this one appear in three places that matter commercially: the written practice that governs how your personnel are qualified, the procedures and technique sheets that define how an examination is actually performed, and the evidence an auditor or client asks for when they want to know why an inspection was accepted. Getting the terminology right is the easy part; being able to produce the qualification record, the calibration traceability and the procedure revision that applied on the day of the inspection is the part that decides audits.
Atlantis NDT provides NDT training and certification against ASNT SNT-TC-1A and ISO 9712, ASNT Level III consulting for written practices and procedure approval, inspection management software that holds qualification, calibration and procedure-revision evidence in recoverable form, and an asset integrity platform that binds inspection results to the asset they describe. Browse the full NDT glossary or ask a Level III directly.