How to Write an NDT Written Practice That Survives an Audit

A written practice is a commitment document, not a summary of the standard

Most rejected written practices fail for one reason: they restate SNT-TC-1A instead of committing to it. The recommended practice is drafted in "should" language and leaves the numbers open on purpose. ASNT's own guidance on employer-based certification puts it plainly — the employer replaces the advisory language with mandatory language, and the resulting document becomes a requirement inside the quality system. A written practice that copies "should" back out of the source has committed to nothing, and an auditor who reaches page three without finding a binding sentence already has a finding.

The document carries three fixed obligations. The employer shall establish it. The employer's NDT Level III shall review and approve it. It shall be maintained on file. Within that frame the employer may modify the basic provisions — training, experience, examination, recertification — but shall not eliminate them. Deleting the practical examination because specimens are inconvenient is not a modification, and dropping the recertification clause because nobody tracks dates is not a simplification. Both are eliminations, and both are written up.

This is also where firms decide whether to build or inherit. Companies producing the document from scratch work through written practice development against their own certificates, method list and record forms. Companies that download a template inherit somebody else's method list, somebody else's hour figures and somebody else's named Level III, then spend the audit explaining why none of it matches.

Scope: name the methods you sell, and nothing else

The scope section states which NDT methods the document governs, which codes and specifications the company works to, and which personnel it covers. Auditors test the boundary in both directions, and both directions hurt. A scope claiming eight methods when the company examines in three invites the auditor to ask for eight sets of training records, eight sets of examinations and eight qualified signatories. A scope naming three methods when a purchase order shows phased array work performed last quarter is a direct nonconformance: testing performed outside the certification program.

Write scope against the current service list and revise it when the service list changes. Adding TOFD means amending the written practice, obtaining the Level III's approval of the amendment, and completing training and examination records before the first job — in that order, not after. The sequence matters because the auditor reads dates. An amendment dated after the first TOFD report converts a paperwork lag into a finding about uncertified work.

Firms selling across maritime, offshore and fabrication normally run one document with a method matrix rather than separate practices per sector. The matrix is where maritime NDT consulting engagements start, because class society and owner specifications add requirements the base practice never contemplated — witness points, specimen types, approval routes — and those additions have to land somewhere the auditor can find them.

Level definitions: write duties, not dictionary entries

SNT-TC-1A defines Level I as performing specific calibrations and examinations under specific written instructions, Level II as setting up and calibrating equipment, interpreting and evaluating results against codes and standards, preparing written instructions and training Level I personnel, and Level III as establishing techniques, interpreting codes and specifications, designating the method and technique to be used, and examining and certifying Level I and II personnel. Copying those three sentences is the floor. The written practices that pass audit go past it.

State what each level is authorized to sign inside your company. Name whether a Level II releases a final report without Level III review. Name whether a Level I performs a calibration unattended. Name which documents carry which signature. An auditor comparing a Level I's signature on a released report against a written practice that grants release authority to Level II holds a finding, and the finding lands on the company, not the technician.

This section is also where limited certifications get their boundaries. If the company certifies technicians for a restricted application — one technique, one geometry, one product line — say so, name the restriction, and make the certificate carry it. Unrestricted certificates issued against restricted training are the quiet version of the same problem, and they surface the first time a technician is asked to cover something the training never touched.

Education, training and experience: the numbers become binding

Table 6.3.1A of SNT-TC-1A lists initial training and experience hours for the employer to consider when writing the practice. Ultrasonic testing sits at 40 hours of organized training and 210 hours of experience in the method at Level I, with a further 40 training hours and 630 cumulative experience hours at Level II. Because the table is offered for consideration, the written practice can set different figures. What it cannot do is state a figure and then certify somebody short of it — that is the gap auditors open training records to find. Method-by-method hour figures are broken out in the NDT training hours guide.

Include the direct-to-Level-II route explicitly if you use it. SNT-TC-1A allows qualification directly to Level II with no time as a certified Level I, provided training and experience total the sum of the hours recommended for both levels. Written practices that stay silent on the route and then produce a Level II certificate with no Level I history hand the auditor a documentation gap. One sentence closes it.

Experience hours are hours in the method under qualified supervision, not hours on payroll. A record showing "employed since 2023" evidences nothing. The written practice should state the form experience is captured on — job type, method, hours, supervising signature — and who reviews it. That form is the artifact the auditor asks for by name, and the companies that designed it the week after an audit are the companies that failed one. Structured classroom hours delivered through corporate NDT training produce the training-hour side of the same record.

Examinations: structure, administration and grading

SNT-TC-1A structures Level I and II qualification as a vision examination, a written general examination on the basic principles of the method, a written specific examination on the equipment, procedures and acceptance criteria used on the job, and a practical examination on representative specimens using at least one flawed specimen with a defined set of evaluation checkpoints. Level III qualification is structured as a basic examination, a method examination and a specific examination. The written practice names the question count for each written part and the checkpoint count for each practical.

Grading is the clause written wrong most often. SNT-TC-1A calls for a composite grade of at least 80 percent with no individual examination graded below 70 percent. For Level I and II the composite is the simple average of the general, specific and practical results. For Level III it is the simple average of the basic, method and specific results. Written practices stating a single 70 percent pass mark, or a single 80 percent, have described a grading scheme the standard does not contain, and every certificate issued under it is questionable.

Administration rules belong in the same section. Examinations shall not be self-administered and shall not be administered by a person the candidate supervises. In-house examination questions require Level III approval before use. A Level III who wrote the questions, sat the specific examination and signed off the result produced three findings from one afternoon — one reason firms route Level III examination and question-bank approval through ASNT Level III consulting services rather than keeping every signature inside the reporting line.

Vision: the shortest clause and the most frequent lapse

SNT-TC-1A (2020) sets near-vision acuity at a minimum of Jaeger Number 2, or equivalent type and size letter, read at the distance designated on the chart and not less than 12 in. (30.5 cm), with an Ortho-Rater minimum of 8 or a similar test pattern accepted as an alternative. That examination is administered annually. Color contrast differentiation demonstrates the capability of distinguishing and differentiating among the colors or shades of gray used in the method, at initial certification and at five-year intervals afterwards.

Write both intervals, both acceptance criteria, and the role authorized to administer the test. State whether corrected vision is acceptable and require the record to note the correction. Two intervals running on two different clocks is precisely why this clause lapses: the annual near-vision date and the five-year color date drift apart, and the file ends up with one current and one expired.

A vision record dated fourteen months before the audit is a finding an auditor writes in under a minute, and it is the most common expired-record finding in NDT programs. The control that closes it is a calendar attached to the certification file rather than to a technician's memory — one tickler per technician, per test, with the next due date on the certificate cover sheet where the reviewer sees it.

Certification, recertification and interrupted service

The certification section names who signs the certificate, what the certificate shows, and how long it runs. SNT-TC-1A (2020) sets a recommended maximum recertification interval of five years for all levels, measured from the date the certifying authority signs the certification record. Earlier editions carried different intervals for Level I and II, so the written practice has to name the edition it invokes. A document that says "per SNT-TC-1A" with no year forces the auditor to pick an edition, and the auditor picks the one that produces the finding.

SNT-TC-1A permits recertification on evidence of continuing satisfactory technical performance, or by reexamination in whichever portions the Level III deems necessary. Choose one route, write it, and build the evidence that route requires. "Continuing satisfactory performance" is not a signature on a renewal form — it is the documented technical performance evaluation SNT-TC-1A calls for, in which the Level III periodically evaluates and records the performance of Level I and II personnel. Firms that select the evidence route and never run the evaluations have selected a route they cannot walk.

Interrupted service and termination need explicit thresholds. SNT-TC-1A leaves the interruption period to the employer, so the written practice states how many consecutive months away from the method triggers reexamination and which portions are reexamined. Termination carries more weight than most firms expect: an employer-based certificate holds only while the employment relationship holds, so a departing technician arrives elsewhere uncertified in your program's terms and a returning one needs a reinstatement route the document has already defined.

Designating the Level III: the signature holding the document up

The written practice names the certifying authority. Under SNT-TC-1A the employer's Level III can be qualified by the employer's own examination or hold ASNT NDT Level III certification, and the document states which route this company accepts, names the individual, and lists the methods that individual is qualified in. That method list is load-bearing. A Level III certified in UT and MT cannot approve a radiographic procedure or certify an RT Level II, and an auditor cross-referencing certificates against procedure approvals finds that mismatch inside an hour.

SNT-TC-1A's qualification routes for Level III run through a four-year engineering or science degree plus one additional year beyond Level II requirements, two years of engineering or science study plus two additional years, or four years beyond Level II in work comparable to Level II in the applicable method. ASNT's own NDT Level III scheme sets parallel eligibility — 12 months (252 days) of NDT experience with a four-year degree, 24 months (504 days) with two years of study, 48 months (1,008 days) with no college — and requires the NDT Basic examination plus at least one Method examination. The route your written practice invokes is the route your records must evidence; the ASNT scheme is set out in full on the ASNT certification page.

Name the deputy. A written practice with exactly one named Level III and no alternate stops functioning the day that person gives notice, and every certificate signed afterwards is unsupported. Companies that name a contracted Level III in the document alongside the staff Level III keep signing authority through a resignation without amending anything — the calculus is worked through in the outsourced versus in-house Level III comparison.

Approval, revision control and the records that prove it

The document carries an approval page with the employer's signature, the Level III's signature, a revision number and a revision date. Auditors check that the copy in the quality system matches the copy in the technician's binder, and that the revision history explains every difference between them. Uncontrolled copies circulating with a superseded method list produce a document-control finding before anyone opens a certification file.

The records section states what is retained, for how long, and where. At minimum: the training record with content and hours, the experience record by method, every examination paper and answer sheet with the grader's marks, the vision records, the technical performance evaluations, and the signed certification record. Examination papers are the record discarded most often, usually because the grade was transcribed to a summary sheet and the paper looked redundant. Their absence converts a compliant certification into an unverifiable one, and unverifiable is the same as absent in an audit report.

Set the review cycle in writing. A practice reviewed once at issue and never again drifts away from actual practice inside two years, and that drift produces the most common audit finding there is — catalogued alongside the other six in the NDT audit findings ranking. Firms that want the gap found before an auditor finds it run an NDT program audit gap assessment against the document and the records together, because neither one on its own shows where they disagree.

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