8.4 MT Reports, Records, and Documentation Review
Key Takeaways
- ASME Section V, Article 7 requires an examination record carrying the Article 1 general information plus the MT equipment and current type, the particles used, the indication record from T-792, the material and thickness, and the lighting used.
- T-792.1 covers nonrejectable indications and T-792.2 covers rejectable indications, and whether nonrejectable indications must be documented is set by the referencing construction code rather than by shop preference.
- T-777 requires that false and nonrelevant indications be proven as false or nonrelevant, so a report must state the evidence used for each such call, not merely the conclusion.
- A multidirectional examination requires a technique sketch under T-778 showing arrangement and connections, magnetizing current for each circuit, and the areas where adequate field strength is obtained.
- Retention periods come from the contract, code, or regulator; FAA-certificated repair stations must retain required work records for at least two years under 14 CFR 145.219.
8.4 MT Reports, Records, and Documentation Review
The official Level III MT topics list "review and approve MT reports" as a task in its own right, alongside determining flaw type and confirming interpretations. That is not administrative filler. The examination record is the only part of a magnetic particle examination that survives it: the particles are wiped off, the part is demagnetized and shipped, and what remains is a document that must be able to defend the disposition years later, in front of an auditor, a customer, or a failure investigation.
What the Code Requires to Be Recorded
ASME Section V, Article 7 devotes its final paragraphs to documentation, and a Level III should be able to navigate them by number:
| Paragraph | Subject | Substance |
|---|---|---|
| T-778 | Multidirectional magnetization technique sketch | A technique sketch is required for each different geometry examined multidirectionally, showing the arrangement and connections, the magnetizing current for each circuit, and the areas of examination where adequate field strengths are obtained. Parts with repetitive geometries but different dimensions may share a sketch when field adequacy is demonstrated per T-756.2. |
| T-779 | Demagnetization | Demagnetize when residual magnetism could interfere with subsequent processing or usage. |
| T-790 / T-792 | Recording of indications | T-792.1 addresses nonrejectable indications and T-792.2 addresses rejectable indications; both are recorded as specified by the referencing Code Section, with location and extent for rejectable indications. |
| T-793 | Examination records | For each examination, the record carries the general information required by Article 1 plus the magnetic particle equipment and type of current used, the particles used, the map or record of indications required by T-792, the material and thickness examined, and the lighting used. |
Two points inside that table decide audit findings:
- Nonrejectable indications are a code topic. Many shops record only rejects. Whether nonrejectable indications must be documented is set by the referencing Code Section, not by the inspector's preference, and the Level III must read the construction code before writing the report form.
- T-777 requires proof, not opinion. "False and nonrelevant indications shall be proven as false or nonrelevant." A report that records "indication observed — non-relevant" with no statement of how that was established (demagnetize and re-shoot, reduce current, blend and re-examine, etch to confirm a permeability boundary) is not a complete record.
ASTM E1444 adds the quality-control dimension: under its Section 7, records of system performance and equipment verification results "shall be maintained and retained for the time period specified in the contract." Verification records and examination records are two different record families, and both are auditable.
The Anatomy of a Defensible MT Report
+-----------------------------------------------------------------------------+
| MT EXAMINATION REPORT - MINIMUM CONTENT SET |
+-----------------------------------------------------------------------------+
| IDENTIFICATION | Customer, order, part number, serial/heat number, |
| | drawing revision, weld/joint identification, stage |
| | (in-process, final, in-service), extent of coverage |
|------------------+---------------------------------------------------------|
| AUTHORITY | Governing code/spec and revision, written procedure and |
| | revision, technique sheet number, acceptance criteria |
|------------------+---------------------------------------------------------|
| PROCESS DATA | Technique (prod/coil/yoke/head/central conductor), |
| | current type and amperage or ampere-turns, pole or prod |
| | spacing, particle type and batch, bath concentration, |
| | surface condition and preparation, part temperature |
|------------------+---------------------------------------------------------|
| VERIFICATION | Field adequacy method and result, white light and UV-A |
| | readings with meter ID, yoke lift check, calibration due |
|------------------+---------------------------------------------------------|
| RESULTS | Indication map/sketch with location, orientation, length;|
| | classification (relevant / non-relevant / false) and the |
| | evidence used to prove it; accept or reject per criteria |
|------------------+---------------------------------------------------------|
| CLOSURE | Demagnetization performed and residual field measured, |
| | post-cleaning performed, examiner name and certification |
| | level, date, Level III review and approval signature |
+-----------------------------------------------------------------------------+
The indication map is the element most often deficient. "Crack, 12 mm, rejected" is unusable for a repair crew; the record must locate the indication unambiguously against a stated datum so the excavation, the repair, and the re-examination all address the same feature.
Level III Review and Approval
Reviewing a report is a technical act, not a signature ritual. A structured review asks:
- Is the authority chain complete and current? Does the cited procedure revision actually cover this material, thickness, coating, and geometry, and was the acceptance criterion taken from the referencing construction code rather than from Section V (which contains none)?
- Do the process data fall inside the qualified ranges? Cross-check the amperage against the technique sheet and against the code formula for the geometry — a 10 in. diameter part recorded at 1 200 A is outside the 300 to 800 A/in. circular range and the report is wrong even if the part was accepted.
- Is the verification evidence contemporaneous? Readings taken "this morning" for a shot fired after a lamp change do not satisfy T-777.2(f), which requires UV-A measurement prior to use, whenever the power source is interrupted or changed, and at completion.
- Are the classifications proven? Every non-relevant and false call needs its stated basis.
- Is the arithmetic right? Aggregate lengths, edge-to-edge spacings, and aspect ratios drive accept/reject decisions and are routinely mis-added.
- Is the record internally consistent? A report stating "dry powder, continuous method" with the current turned on after particle application contradicts T-773(a) and signals either a transcription error or a real process deviation.
Where a report fails review, the Level III does not quietly correct it. The finding is raised against the examiner and the process, the report is re-issued under revision control with the original retained, and if parts have shipped, the Level III initiates the same quarantine-and-disposition logic used for a failed calibration.
Retention, Traceability, and Electronic Records
- Retention period comes from the contract, the referencing code, or the regulator — not from habit. FAA-certificated repair stations, for example, must retain the required work records for at least two years under 14 CFR 145.219, while pressure-vessel and nuclear records are commonly retained for the life of the item.
- Traceability must run in both directions: from the part serial number to the examination record, and from the examination record back to the specific equipment, particle batch, bath, meter calibrations, and certified examiner in effect that day. A record naming "Bench 3" is only useful if Bench 3's calibration history is retrievable for that date.
- Electronic records are acceptable where the system provides controlled access, attributable electronic signatures, revision history, and protection against undetected alteration. Scanning a signed paper form into an uncontrolled shared folder satisfies none of those and is a standard audit finding.
- Deviation and nonconformance records belong with the examination record: what was out of specification, the technical justification, the disposition, and the authority who approved it.
Under ASME Section V, Article 7, who decides whether nonrejectable magnetic particle indications must be documented in the examination record?
An MT report states: 'Two linear indications observed in HAZ, both non-relevant, weld accepted.' What is the principal documentation deficiency under ASME Section V, Article 7?
A Level III reviewing a completed report finds a 10 inch diameter solid shaft recorded as examined by direct contact circular magnetization at 1200 Amperes, with the part accepted. What should the review conclude?
Which set of records makes an MT examination traceable in both directions during an audit?