Inspection personnel and certification

Codes trust inspectors with judgments that can stop a job, so they insist that inspectors prove their competence. Devon has worked beside Lucia for three years and has met the owner's inspectors, the NDE technicians, the radiographers and the pressure equipment inspectors who visit Hartwell. In this lesson he learns how each of them is certified, what their certification lets them do, and how a welder might one day become one. Lucia, who started as a welder herself, tells the class that the best inspectors she knows were good welders first, because they know where a weld goes wrong and how hard it is to make it go right.

Why inspectors are certified

A weld inspector makes decisions that cost money and affect safety. Reject a good weld and the shop pays for a repair that adds heat and risk for nothing; accept a bad weld and it goes into a bridge or a refinery. Codes therefore require that the people who inspect, and the people who perform non-destructive testing, be qualified by training, experience and examination, and that their qualifications be documented. Certification schemes provide the documentation, and they also set rules of conduct: inspectors must be impartial, report what they find, and not inspect work they have a personal stake in.

There are two broad kinds of certification. Central or third-party certification is granted by an independent body after examination, and the certificate belongs to the person; it travels with them from employer to employer. Employer-based certification is granted by the employer under a written practice, often using examinations designed or approved by a senior specialist, and it lasts only while the person works for that employer. Both are accepted by codes, depending on the country and the code, and some schemes combine them.

Welding inspectors

In the United States, welding inspectors are most often certified by AWS under AWS QC1, Standard for AWS Certification of Welding Inspectors. A Certified Welding Inspector, or CWI, has passed three examinations: fundamentals of welding and inspection, a practical examination using tools and samples, and an open-book examination on a code such as D1.1 or Section IX. Eligibility depends on education and welding-related work experience, from one year with a technical degree to longer with less schooling, and a visual acuity test is required. Certification runs on a nine-year cycle, with renewals at three and six years and recertification at nine. There is also a Certified Associate Welding Inspector, who works under a CWI, and a Senior Certified Welding Inspector. Lucia is a CWI.

D1.1 accepts several bases for an inspector's qualification: AWS QC1 certification as a CWI or SCWI, certification to CSA W178.2 at Level 2 or 3, or an engineer or technician who by training and experience is qualified to inspect. Building codes add a role for special inspectors: under the International Building Code, the owner engages a special inspector, approved by the building official, to inspect structural welding on many projects, and many special inspectors hold both a CWI and certification from the International Code Council. The owner's inspector on the Riverside bridge is a CWI working for an engineering firm hired by the city.

NDT technicians

NDT certification in the United States is mostly employer-based. The employer writes a written practice that follows ASNT's recommended practice SNT-TC-1A, setting training hours, experience, examinations and vision tests for each method and level, and its Level III approves the examinations and certifies the technicians. Where a contract or code requires it, the stricter ANSI/ASNT CP-189 standard is used, which sets minimums that cannot be reduced and requires re-examination for recertification. ASNT also offers central certification, including the ASNT Level III, which employers can recognize in their written practice. Because employer certification ends when the technician leaves, a new employer recertifies under its own practice.

Levels mean roughly the same everywhere. A Level 1 can carry out specific calibrations and tests under supervision, following written instructions, and record results, but does not evaluate them alone. A Level 2 can set up and calibrate equipment, carry out and supervise tests, interpret and evaluate results against codes and specifications, and write instructions. A Level 3 can establish techniques and procedures, interpret codes, designate the methods to be used and train and examine others. Annika is a Level 2 in three methods; her company's Level 3 approves her procedures.

Vision matters for every method. Certification schemes require a near-vision acuity test at least once a year for NDT personnel and a color perception test where the method needs it, such as color-contrast penetrant. An inspector whose glasses prescription has changed must retest before inspecting.

Pressure equipment inspectors

For code pressure equipment, the authorized inspector is a National Board commissioned inspector employed by an authorized inspection agency, usually an insurance company or a firm accredited for the work. The authorized inspector reviews the manufacturer's quality control system, procedures and welder records, inspects at the hold points, witnesses pressure tests and signs the data reports before the code stamp is applied. State and city boiler inspectors inspect installed boilers. Large owners such as refineries also have their own in-service inspectors, often certified by the American Petroleum Institute as pressure vessel or piping inspectors.

The independence of these inspectors is the point of their job. They do not work for the shop, and they cannot be told to accept work. A shop that has a disagreement with an authorized inspector or a safety codes officer raises it through the channels the jurisdiction provides, never by pressure on the inspector.

Records and renewals

Every certification has an expiry and conditions for keeping it. Inspectors renew by showing continued work, by re-examination or both, and by passing vision tests at set intervals. A shop that relies on inspectors' certifications must check that they are current, and an auditor will ask to see them. Hartwell keeps a list of every certified person who inspects or tests its work, with the certificate number, method, level, expiry and last vision test.

# Certification register for people who inspect or test Hartwell's work
from datetime import date
today = date(2026, 11, 2)
register = [
    # name, certification, method or scope, expiry, last near-vision test
    ('Lucia Ferreira', 'welding inspector', 'visual, all codes', date(2028, 4, 30), date(2026, 3, 12)),
    ('Annika Sorensen', 'NDT Level 2', 'UT', date(2027, 1, 15), date(2025, 10, 20)),
    ('Annika Sorensen', 'NDT Level 2', 'MT', date(2029, 6, 1), date(2025, 10, 20)),
    ('Annika Sorensen', 'NDT Level 2', 'PT', date(2026, 12, 1), date(2025, 10, 20)),
    ('contract radiographer', 'NDT Level 2', 'RT', date(2027, 8, 9), date(2026, 7, 2)),
]
for name, cert, scope, expiry, vision in register:
    notes = []
    if (expiry - today).days < 0:
        notes.append('EXPIRED')
    elif (expiry - today).days < 60:
        notes.append(f'expires in {(expiry - today).days} days')
    if (today - vision).days > 365:
        notes.append('near-vision test overdue')
    print(f"{name:<22} {cert:<18} {scope:<18} {'; '.join(notes) if notes else 'current'}")

Lucia Ferreira         welding inspector  visual, all codes  current
Annika Sorensen        NDT Level 2        UT                 near-vision test overdue
Annika Sorensen        NDT Level 2        MT                 near-vision test overdue
Annika Sorensen        NDT Level 2        PT                 expires in 29 days; near-vision test overdue
contract radiographer  NDT Level 2        RT                 current

The register shows that Annika's penetrant certification expires within the month and that her annual near-vision test is overdue for every method. Until she retests her vision, she cannot perform or sign any examination, even in methods whose certificates are current. Lucia sends the list to Annika's company the same day; she is retested that week and her renewal paperwork goes in. An auditor checking Hartwell's records would have found the same gap, which is why the shop checks first.

Ethics and independence

Certification schemes include a code of conduct, and the rules are simple to state. Inspect and report honestly, including findings that are inconvenient. Do not sign for inspection you did not do. Do not inspect your own work for acceptance when the code requires independent inspection. Do not accept gifts or favors from those whose work you inspect. Keep records accurate and complete. Work only within the scope and level of your certification. An inspector who breaks these rules can lose certification, and the welds they accepted may have to be reinspected at the shop's cost.

Lucia has two stories she tells new inspectors. The first is about a foreman, long gone from Hartwell, who asked her to sign off a batch of welds she had not seen because the truck was waiting; she did not sign, the truck waited two hours, and two of the welds were rejected. The second is about a welder who asked her to check his own suspicion about a root he had just run; she did, it was fine, and he became one of the best welders in the shop because he was never afraid to ask. Inspection, she says, is not the enemy of production; it is the reason the customer believes in it.

From welder to inspector

Many inspectors start as welders. A welder with enough years of welding-related experience can take the AWS CWI examinations, often after a preparatory course, and begin by working as a CAWI under a CWI if the experience requirement is not yet met. NDT is a separate path through an employer's training program and written practice, with its own classroom and on-the-job hours. Both paths reward the habits Devon has been building: keeping a notebook, reading the procedure before welding, and understanding why a weld fails as well as how to fix it.

Calibration of inspection equipment

A certified inspector with an uncalibrated gauge produces uncertain results. Codes and quality programs require that measuring and test equipment used for acceptance be calibrated at set intervals against standards traceable to national standards, and that each item carry a label or record showing when it was last calibrated and when it is next due. At Hartwell this covers fillet and cam gauges, tapes, thermometers and temperature-indicating crayons, clamp-on current meters and voltmeters used to check welding machines, light meters, ultrasonic instruments and their calibration blocks, magnetic particle yokes and test weights, and the pressure gauges used for hydrostatic tests.

Some checks are done every day rather than at long intervals. Annika checks her ultrasonic instrument against a reference block at the start and end of each shift and whenever the probe or cable is changed; if the final check shows a shift, every weld tested since the last good check is retested. The yoke lift test is done before use. The radiographers check their survey meters. These daily checks are recorded on the test report, and an auditor will look for them.

A day with the owner's inspector

On a Thursday Devon spends the day with the owner's inspector for the Riverside bridge, a quiet engineer named Farhan Qadir who has inspected bridges for twenty years. Farhan starts by reading Hartwell's inspection records for the week, then walks the shop to see the work they describe. He picks two splices that Lucia has accepted and asks Annika to scan them again while he watches. He checks the welders' qualifications for the girders he sees being welded, the procedure posted at each station, and the preheat on a thick flange with his own thermometer. At the end of the day he writes a short report for the city: work in progress, inspections witnessed, records reviewed, and one observation about a missing date on a preheat record, which Lucia corrects before he leaves.

Devon notices that Farhan does not repeat everything Lucia does. Verification inspection samples the fabricator's work and checks that the fabricator's system works; it is not a second complete inspection. When the samples agree, the owner gains confidence in the records for the rest; when they do not, the owner's inspector widens the sample and the fabricator may have to reinspect. The relationship works best when both inspectors are certified, honest and talk to each other, which on this job they do every morning over coffee.

Inspection reports that stand up

Whatever the certification, an inspector's value lies in reports that someone else can rely on months later. A good report identifies exactly what was inspected, by drawing, weld number and location; states the method, the procedure and its revision, and the acceptance criteria and their edition; records the equipment and its calibration; describes each indication found and how it was evaluated; gives a clear result; and carries the inspector's name, certification and level, signature and date. It is written at the time, not reconstructed later, and corrections are made by striking through and initialling, never by erasing.

Lucia keeps her reports to a standard form for each method, so that nothing is forgotten, and reviews each one before it leaves her desk. Devon learns to read them the way an auditor would: if the report did not say it, assume it was not done. That habit is what makes a certified inspector worth more than an experienced pair of eyes alone.