Inspection Practice
Planning the inspection
Good inspection starts before the arc is struck. Review drawings, the WPS, the inspection and test plan, and any customer specification. Confirm joint preparation: included angle, root face, root gap, bevel cleanliness and fit-up. Dimensional checks, preheat verification and consumable control belong to this stage. A frequent exam trap is a scenario describing excellent final visual inspection but no pre-weld check; the expected answer usually points to fit-up or preheat as the missed control.
Measuring and judging
Use the right gauge for the feature: a weld gauge or fillet gauge for leg length and throat, a taper or undercut gauge for depth, and a straight edge for distortion. Measure at several points along the weld, not one convenient spot. Compare results against the acceptance criteria of the applicable code, and remember that criteria differ by joint type and by whether the weld is statically or cyclically loaded. Traps include confusing leg length with throat thickness (throat equals leg times 0.707 for a 45-degree equal-leg fillet), and accepting a weld because it is visually smooth when a measured dimension fails.
Worked example and rule of thumb
A 10 mm equal-leg fillet has a measured throat of 6 mm. Required throat for a 10 mm leg is 7.07 mm, so the weld is under size and fails even though it looks full. Rule of thumb: measure, calculate, compare, record. Also plan for the sequence: root inspection before capping, in-process checks on layers, final visual, then any required NDT. Document each stage with date, location, result and inspector identity.
Documentation and Safety
Records that stand up
Inspection records must be contemporaneous, legible, traceable and signed. A useful report identifies the project, drawing and WPS revision, the welder and their certificate, the date, the standard applied, the results of each check, and any nonconformance with its disposition. Understand the difference between a nonconformance report (describes the departure) and a corrective action (prevents recurrence). Traps include reports that state a conclusion without the measurement that supports it, and records that are unsigned or undated, which usually makes them unacceptable as quality records. Never alter a record after the fact; add a dated correction instead.
Safety around welding inspection
An inspector works near arc radiation, fume, hot metal, noise and electrical hazards. Eye protection must match the task: a filter shade appropriate to the process and current when observing the arc, and safety glasses with side shields for general inspection. Wear flame-resistant clothing, leather gloves, and hearing protection where required. Check ventilation and fume extraction before entering a confined space, and never enter without a permit, gas testing and an attendant. Arc flash can injure even at a distance, so use screens and warn others. Traps often present a plausible control that is actually wrong, such as relying on a dust mask for welding fume.
Worked example and rule of thumb
You are asked to inspect inside a tank that held solvent. The correct answer is not "wear a respirator"; it is to follow confined-space entry procedure: isolate, clean, test the atmosphere, obtain a permit, use an attendant and rescue plan. Rule of thumb: no permit, no entry. Record the entry and the gas test results, and stop work if conditions change.