Inspection & Testing (ET105) common mistakes
Inspection & Testing (ET105) · Understand the traps and how to avoid them.
Treating 'inspection' and 'testing' as interchangeable and describing a test method when a question asks what an inspector does during inspection, or vice versa.
Candidates study the NDE and mechanical testing content heavily and then apply test vocabulary to any prompt, missing the distinction between examining against requirements (inspection) and measuring performance under defined conditions (testing).
What to do instead
Before answering, classify the activity in the stem: is it comparing a characteristic to a requirement, or subjecting a specimen to conditions to obtain a result? Match the verb in the option to that classification.
Citing a standard by a remembered clause number or edition year without verifying that the clause actually contains the requirement quoted.
Candidates memorize clause numbers as anchors and assume they remain stable across editions; clauses are renumbered and requirements are relocated between revisions.
What to do instead
Anchor answers to the requirement's content and the edition stated in the stem, not to a memorized clause number. If the stem does not state an edition, choose the option that describes the requirement rather than one that asserts a specific clause.
Confusing a code requirement with a standard's recommended practice or a customer specification, and selecting the strictest option regardless of which document governs.
Candidates assume the most conservative answer is always correct, but the exam tests whether you know which document controls and whether a recommendation is mandatory.
What to do instead
Identify the governing document named in the stem and its force (shall vs. should vs. may). Only escalate to a stricter requirement if the stem indicates the governing document or contract mandates it.
Describing visual inspection as a quick glance and omitting prerequisites such as lighting level, surface condition, access, viewing distance, and inspector qualification.
Visual inspection feels intuitive, so candidates answer from everyday experience rather than from the controlled conditions the method requires.
What to do instead
For any visual inspection item, state the required illumination, surface preparation, angle and distance, and the qualification or vision requirement of the inspector before stating what is looked for.
Mixing up which NDE method detects which discontinuity orientation, for example expecting radiography to reliably find tight planar discontinuities oriented parallel to the beam.
Methods are learned as lists of capabilities rather than as physical interactions between the probing energy and the discontinuity geometry.
What to do instead
For each method, reason from the physics: what energy is used, how it interacts with a void or interface, and which orientation gives the strongest signal. Answer by orientation and geometry, not by method reputation.
Reporting a tensile strength or yield value from a test without noting the specimen geometry, orientation, strain rate, or whether the value is upper or lower yield.
Candidates focus on the calculated number and treat the test as producing a single unambiguous property, ignoring that the result is conditional on specimen and procedure.
What to do instead
State the property definition being used, the specimen type and orientation, and the test conditions alongside the value. If a stem gives only a load and an area, verify you are computing the intended property before selecting.
Quoting a measurement result as an exact value with no tolerance, resolution, or uncertainty statement, or adding uncertainties that should be combined in quadrature arithmetically.
Candidates conflate accuracy, precision, resolution, and uncertainty, and default to simple addition of error terms.
What to do instead
Separate the concepts: resolution is the smallest readable increment, accuracy is closeness to true value, uncertainty is the interval characterizing the result. Combine independent standard uncertainties by root-sum-square unless the stem specifies otherwise.
Choosing an arbitrary sample size or selecting the most convenient units instead of applying the sampling plan, random selection, and acceptance number stated or implied in the stem.
Candidates treat sampling as a formality and answer from intuition about 'enough' samples, missing that the plan defines both the sample size and the decision rule.
What to do instead
Extract the plan parameters first: lot size, sample size, acceptance and rejection numbers. Decide accept, reject, or resample strictly from those numbers, and treat non-random or convenience selection as invalidating the sample.
Recording a result as 'pass' or 'fail' in the report without the measured values, test conditions, instrument identification, and the specific acceptance criterion applied.
Candidates view the report as a summary of the conclusion and assume traceability is handled elsewhere, but the report is the record that must stand alone.
What to do instead
Before finalizing any reported result, confirm it includes the measurement data, conditions, equipment and calibration reference, the criterion with its source, and the disposition. If any element is missing, the record is incomplete regardless of the conclusion.
Answering safety or ethics items by choosing the option that satisfies the schedule or the customer, such as releasing product pending paperwork or accepting a verbal waiver of a required test.
Candidates read for operational efficiency under exam time pressure and undervalue the authority of the inspector to stop work and the requirement for documented, authorized deviations.
What to do instead
Apply the priority order: safety of people, integrity of the result, then schedule. Any deviation from a specified requirement needs documented authorization from the responsible authority before work proceeds or product is released.