When a structural weld fails NDE, the first question from an EOR or third-party auditor is not just "what did the test show?" — it's "who ran the test, and are they qualified to interpret it?" AWS D1.1:2025 ties NDE acceptance directly to the qualification of the personnel performing and interpreting the examination. A valid NDE report from an under-qualified technician is not a valid NDE report.
This matters practically: an owner or AHJ can reject NDE documentation — and require retesting — if the certifying technician's qualifications don't match the method, level, and written practice the project requires. QC managers who receive NDE reports from subcontractors should verify personnel credentials as a standard step, not an afterthought.
What AWS D1.1 says about NDE personnel
AWS D1.1:2025 requires that nondestructive examination personnel be qualified and certified in accordance with a written practice that meets the requirements of ASNT SNT-TC-1A or ASNT CP-189. The written practice is the employer's documented program specifying education, training, experience, and examination requirements for each NDE method and level. It is not optional — qualification without a supporting written practice is not valid under the code.
For ultrasonic testing specifically, AWS D1.1 includes additional UT procedure requirements that technicians must follow, covering calibration, scanning methods, and report format. Meeting ASNT certification alone is necessary but not sufficient for UT; the technician also must operate under a UT procedure that meets the code's requirements.
Rule library based on AWS D1.1:2025; verify against your governing edition.
The ASNT qualification levels
ASNT publishes two parallel frameworks for NDE personnel qualification:
Level I can perform specific calibrated tests under the supervision of a Level II or III. A Level I cannot independently interpret results or determine whether a flaw is acceptable. They follow a procedure; they do not evaluate what the procedure finds.
Level II can set up equipment, calibrate, perform the test, interpret results, evaluate findings against acceptance criteria, and prepare reports. Level II is the minimum required for issuing an NDE report that stands on its own — and for any work where a technician is the sole responsible party on the project.
Level III can establish NDE procedures, interpret codes and standards, train and certify Level I and II personnel, and approve written practices. On complex structural projects, the Level III typically approves the NDE procedure; Level II examiners do the actual production work.
Each level is method-specific. A Level II in ultrasonic testing is not automatically qualified for radiographic testing or magnetic particle testing. They are treated as separate disciplines — a technician can hold multiple Level II certifications, but each must be qualified and documented independently.
SNT-TC-1A vs. ASNT CP-189: which standard applies
SNT-TC-1A (Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing) is a guideline. An employer develops a written practice "based on" SNT-TC-1A, but the employer sets the specific hours of training, examination scope, and renewal interval within the document's guidance. Two companies can both comply with SNT-TC-1A while having meaningfully different qualification thresholds.
CP-189 (Standard for Qualification and Certification of Nondestructive Testing Personnel) is a standard, not a recommended practice. It sets fixed minimum requirements for education, training hours, and examination content that are not adjustable by the employer. A technician certified under CP-189 holds a credential that is more portable and comparable across employers.
Many owner specifications and AISC fabricator certification programs now require CP-189 instead of SNT-TC-1A precisely because of the consistency it provides. If your contracts specify CP-189, SNT-TC-1A-based certifications from subcontractor NDE firms are not interchangeable — verify before the NDE starts, not after.
Visual inspection is separate
The CWI credential — Certified Welding Inspector — qualifies the holder for visual inspection of welds. That scope covers the checks in AWS D1.1's visual acceptance criteria: weld size, profile, surface defects, arc strikes, undercut, and similar surface-observable conditions. See visual acceptance criteria under AWS D1.1 for what VT covers.
Visual inspection does not qualify a CWI to perform or interpret RT, UT, MT, or PT. These are distinct method qualifications, maintained independently of the CWI credential. A CWI who is also an ASNT Level II in UT holds two separate, separately-maintained certifications.
This distinction matters in project documentation. The CWI signature on the visual inspection record and the UT Level II signature on the ultrasonic test report should be different fields, potentially different people. Auditors who find a single technician's name on all NDE report types will look closely at their individual method certifications.
What to check on incoming NDE reports
When QC managers receive NDE reports from an NDE contractor — common on projects where the fabricator subcontracts radiographic or ultrasonic testing — verify:
- Method certification: The report must identify the technician's level (Level I, II, or III) and the specific method (UT, RT, MT, PT). Level I signatures require a Level II or III co-signature for the report to be independently valid.
- Employer written practice: The NDE firm should be able to provide their written practice on request. Confirm it references SNT-TC-1A or CP-189 and covers the relevant method.
- Certification currency: ASNT certifications expire. SNT-TC-1A certifications are typically renewed every five years; CP-189 certifications have specific renewal requirements. An expired certification renders the associated NDE reports questionable for audit purposes.
- Procedure compliance: For UT specifically, confirm the procedure used meets AWS D1.1 requirements — transducer frequency, calibration block type, scanning coverage, and decibel reference.
For audit-packet purposes, retain the technician's certification record alongside the NDE reports themselves. See NDE documentation and audit-packet requirements for how to organize the full package.
Common audit findings
Third-party audits of structural welding QA programs consistently flag a handful of NDE personnel issues:
- Level I signing independently: The NDE report shows a single Level I signature with no Level II or III co-signature. The report has no independent interpretive authority.
- Wrong method listed: The certification on file is for MT; the technician performed UT. Method-specific qualifications are not interchangeable.
- Expired certifications: Certifications were valid when the welds were examined but have since lapsed. Auditors pull the dates; if the cert expired before the test date, the documentation is deficient.
- No written practice on file: The NDE contractor was qualified under an internal written practice that the fabricator never requested or retained.
For a broader picture of how NDE fits into the documentation package, see NDE sampling rates and spot vs. full inspection under AWS D1.1 and NDE method selection for structural welds.
Practical setup for QC managers
Before the first production weld on a structural project:
- Request the NDE contractor's written practice and confirm it meets the contract-specified standard (SNT-TC-1A or CP-189).
- Collect copies of individual technician certifications for each NDE method that will be used.
- Set a calendar reminder for certification expiration dates if any fall within the project schedule.
- Confirm whether the project specification requires CP-189 — if so, get that in writing from the NDE contractor before they mobilize.
Managing NDE personnel credentials alongside WPS, PQR, and welder qualification records is straightforward with a digital QA system. WPS welding software keeps all qualification records in one place so credential gaps surface before inspection, not during an audit.