Experience logs that prove the hours happened
An NDT experience log records time a candidate spent performing a specific method under qualified supervision, entry by entry: date, hours, the work done, the supervisor and a verification signature. It is the evidence that the experience your written practice requires was actually gained. Organized training does not count toward it, and an unverified total proves nothing.
ASNT SNT-TC-1A defines experience as work activities in a specific NDT method under the direction of qualified supervision, including performing the method and related activities, and excluding time spent in organized training programmes. Its recommended tables distinguish experience in the method from total NDT experience; ANSI/ASNT CP-189 sets its own requirements, and your written practice turns either into the figures your programme uses. The experience log is where certifications tend to rest on assertion: a single letter claiming a total, a log written up from memory just before the examination, the same period claimed under two methods, or a supervisor who was not certified in the method at the time. For new hires the problem moves into someone else's records. Atlantis designs log formats and verification steps, drafts prior-experience verification templates, and reviews existing logs before certification or an audit.
Source: ASNT SNT-TC-1A (2024, with Addendum), definition of experience and recommended experience tables; ANSI/ASNT CP-189 (2024); the employer's written practice.
| Log element | Defensible entry | Weak entry | Consequence at audit |
|---|---|---|---|
| Date and duration | Date and the hours spent in the method that day | A weekly or monthly total | Hours cannot be checked against timesheets or job records |
| Method and technique | Method, plus technique where the written practice certifies by technique | NDT, or a job title | Hours cannot be allocated to a certification |
| Work performed | Job or report number, component and tasks done: set-up, calibration, scanning, evaluation, reporting | Assisted crew | No way to tell performing the method from watching it |
| Supervisor | Name, method and level of the supervisor, certified on that date | A first name or the crew lead | Supervision by someone unqualified is not qualified supervision |
| Verification | Supervisor initials per entry or per page, with Level III review before certification | One signature on the final total | The whole total rests on a single assertion |
| Allocation | Each hour assigned to one method, with combined work split by a stated rule | The same days in two method logs | A double-counting finding against every affected certification |
| Corroboration | Report numbers or timesheet references for each entry | None | Nothing independent supports the hours |
Why auditors spend time on the experience log
Training produces certificates and examinations produce graded papers, but experience is recorded by the candidate and a supervisor, frequently under time pressure and frequently after the fact. That makes it the record most open to optimism. Auditors know this, so they read logs closely: entry dates against job records, supervisors against certification files, totals against the written practice. A certification that rests on a weak log is exposed even when every other record in the file is sound.
The fix is not more paperwork but better-designed paperwork. A log built so that each entry names the job, the task and the supervisor, and is initialled close to the time the work was done, takes moments at the end of a shift. Rebuilding a log from memory before an examination, or after an audit finding, takes far longer and convinces nobody.
Entry-level logs versus summary sheets
Two formats dominate. A daily or per-job log records each period of work as it happens, with supervisor initials. A summary sheet records totals by month or project, signed by a supervisor at the end. Summary sheets are faster to complete and much weaker as evidence, because a single signature vouches for a long stretch of work nobody can now test. Where a summary is used, it should cite the job records or reports behind each line so the total can be rebuilt if challenged.
The log should also capture technique, product form and code where your written practice certifies to those distinctions. A UT log that does not separate thickness measurement from weld examination, or manual techniques from encoded ones, cannot support a certification limited to one of them or extended to another. Designing those fields in from the start is easy; adding them later means reconstruction.
Supervision that counts as qualified supervision
Qualified supervision means supervision by someone certified in the method at a level the written practice accepts for directing trainees, on the date of the work. Three problems recur. The supervisor held a different method. The supervisor's own certification had lapsed. The supervisor was a crew lead or project manager with no NDT certification at all. Each turns logged hours into unsupervised hours, which the written practice will not credit.
Supervisors should sign with a name and certification reference, not just initials, at least on the first page they sign. Keep a copy of their certification record from the period, because a supervisor who leaves takes the proof of their qualification with them. The Level III's review before certification should check every supervisor named in the log against that evidence and record the check.
Prior experience for new hires
Experienced hires bring hours gained under someone else's supervision and someone else's written practice. Under employer-based certification, those hours count only after the new employer has verified them and decided they meet its own written practice. That means a verification letter from each previous employer stating hours by method, the period, the type of work and the supervisor, followed by a documented confirmation, not just the letter on file.
Where previous employers have closed, merged or stopped responding, the new employer can look for corroborating evidence: old certification letters, reports bearing the technician's name, client approvals. The written practice should say what corroboration is acceptable and who decides. SNT-TC-1A treats certification as ending when employment ends, so a previous employer's certification letter is evidence, not a certification the new employer inherits; if your written practice offers any route that relies on prior certification, it should state the conditions and the file should show each one met.
Findings auditors write against experience records
The same findings appear across very different companies. Logs with no supervisor named, or a supervisor certified in another method. Totals that include course time. Identical hours claimed in two method logs for the same period. Logs that begin after the certification date, showing they were completed to justify a decision already taken. Prior experience accepted on the strength of a CV. Certification letters issued before the Level III reviewed the log, with the review signed later.
Each finding has the same root: the log was treated as a formality rather than as evidence. An internal audit that samples logs against job records, before a client does, is the quickest way to find out which of these your files carry. Our NDT audit consulting work includes that sample, and the result feeds directly into the corrective actions below.
Repairing a log without rewriting history
When a log is weak, the temptation is to rewrite it neatly. Resist it. A reconstructed log must say it is a reconstruction, with the date it was prepared, who prepared it, the sources used, such as timesheets, reports and job files, and a Level III review of each reconstructed entry. Hours that cannot be corroborated from independent records should not be counted, however confident the technician is that the work was done.
If the corroborated hours fall short of the written practice requirement, the certification decision has to follow the evidence: additional supervised experience, a limited certification where the written practice allows one, or a reassessment of reports signed in the interim. That is uncomfortable, but it is the position an auditor will reach anyway, and reaching it first, with a documented corrective action, is the defensible version.
What Atlantis delivers on experience records
We design log formats suited to your work, from paper logs for field crews to fields a digital system can capture, with method, technique, job reference, task, supervisor and verification built in. We draft prior-experience verification letters and confirmation records for new hires, written practice wording on supervision, allocation and reconstruction, and a review procedure for the Level III. Existing logs are reviewed by an ASNT NDT Level III and each candidate's corroborated total is reported.
Engagements usually begin with the people closest to certification or recertification, and with any new hires whose prior experience was accepted without verification. Request a quote for an experience log review and tell us the methods involved and roughly how many technicians' files are in scope.
What counts as NDT experience hours?
Time spent doing work in the specific method under qualified supervision, including the related activities that belong to the method, such as set-up, calibration, evaluation and reporting. Time in organized training does not count. Watching someone else work is weak evidence unless the written practice defines how observation is credited. Every log entry should make the activity visible.
Can practical sessions in a training course count as experience?
No. Practical exercises inside an organized course are training, however realistic the specimens. They belong in the training record. Experience starts when the candidate does production or production-equivalent work under qualified supervision, and the log should begin there. Mixing the two is one of the first things an auditor separates out, and only the remainder counts.
Who may sign an NDT experience log?
A supervisor certified in the method at the level your written practice requires for supervision, on the date of the work. The Level III, or a designee, then reviews the log before certification. Keep a copy of each supervisor's certification record from the period, so the signature can be checked long after the supervisor has moved on.
How do we verify experience claimed by a new hire?
Ask each previous employer for a letter on its letterhead stating hours by method, the period, the type of work and who supervised, then confirm it directly and note the confirmation. Compare it with the CV and prior certification records. Under SNT-TC-1A certification ends with employment, so the previous certification is evidence for your decision, not something you inherit.
Can hours in one method count toward another?
Not as method experience. Each method's log stands alone, and combined jobs need a written allocation rule, such as recording MT and PT time separately even when performed on the same weld. Total NDT experience, where your written practice uses it, can draw on all methods, which is why the ledger should carry both figures.
Do phased array or TOFD hours need logging separately from UT?
Yes, whenever your written practice certifies by technique or a code or client specification sets technique-specific experience, as ASME Section V does for computerized imaging techniques. Log the technique in every entry from the start. Splitting a general UT total into techniques after the fact is reconstruction, and auditors treat it as such.
Frequently asked questions
Is a CV enough evidence of prior NDT experience?
No. A CV is the candidate's own account. Prior experience needs confirmation from the employer that supervised it, stating hours by method, the period and the supervisor, plus a record of how the confirmation was obtained. The CV is useful for spotting gaps and inconsistencies, not for counting hours.
Can technicians keep their own experience logs?
Yes, and they generally should, because they know what they did. What turns the log into evidence is the supervisor's verification close to the time of the work and the Level III's review before certification. A self-kept log with neither is a diary.
Our supervisor has left the company. Are their signatures still valid?
Yes, if they were certified in the method when they signed. Keep a copy of their certification record from that period in the file, because you can no longer ask them for it. If that copy is missing, note what other evidence shows their status at the time.
Does a digital log need anything a paper log does not?
It needs an audit trail. Entries should show who made them and when, edits should be visible rather than overwriting the original, and supervisor approval should be tied to the supervisor's own login. Without those, an auditor cannot tell a contemporaneous entry from one typed in recently.