Inspection & Testing (ET105) flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Accuracy vs. precision

Accuracy is closeness to the true value; precision is closeness among repeated measurements. A measurement can be precise but inaccurate if a systematic bias exists.

Defect

A nonconformity that is severe enough to render a product unfit for its intended use. It is a subset of nonconformities that affect safety or function.

First article inspection

A verification that the manufacturing process can produce parts meeting all drawing and specification requirements. It is performed on the first production unit or lot.

Traceability

The ability to trace the history, application, or location of an item by means of recorded identification. It links materials, processes, and test records to the finished product.

Code vs. standard

A code is a set of rules adopted by a jurisdiction with the force of law. A standard is a consensus document that may be referenced by a code or contract.

ISO/IEC 17025

An international standard specifying general requirements for the competence of testing and calibration laboratories. It covers management, technical, and quality system requirements.

ASME Section IX

Part of the ASME Boiler and Pressure Vessel Code that covers qualification of welding and brazing procedures, welders, brazers, and operators.

AWS D1.1

The structural welding code for steel, published by the American Welding Society. It defines acceptance criteria for visual and NDT examination of welds.

Visual inspection

The primary NDT method that uses the unaided eye or optical instruments to detect surface discontinuities, corrosion, misalignment, and workmanship defects. It requires adequate illumination.

GD&T

Geometric dimensioning and tolerancing, a system for defining and communicating engineering tolerances. It controls form, orientation, location, and profile per ASME Y14.5.

Surface roughness Ra

The arithmetic average of the absolute values of the profile height deviations from the mean line. It is a common measure of surface finish, typically in micrometers or microinches.

Liquid penetrant testing

An NDT method that detects surface-breaking discontinuities in nonporous materials. It uses a penetrant, a developer, and either visible or fluorescent dye.

Magnetic particle testing

An NDT method that detects surface and near-surface discontinuities in ferromagnetic materials. It uses magnetic fields and iron particles to reveal leakage fields.

Ultrasonic testing

An NDT method that uses high-frequency sound waves to detect internal discontinuities and measure thickness. It requires a couplant to transmit sound into the material.

Radiographic testing

An NDT method that uses X-rays or gamma rays to produce an image of internal structure. It detects volumetric discontinuities and requires radiation safety precautions.

Eddy current testing

An NDT method that detects surface and near-surface discontinuities in electrically conductive materials. It is commonly used for tubing inspection.

Tensile testing

A destructive test that measures yield strength, ultimate tensile strength, elongation, and reduction of area by pulling a specimen until failure.

Charpy impact test

A destructive test that measures the energy absorbed during fracture of a notched specimen. It evaluates toughness and ductile-to-brittle transition behavior.

Hardness testing

A destructive test that measures resistance to indentation. Common scales include Brinell, Rockwell, and Vickers; results are empirical and scale-specific.

Bend test

A destructive test that evaluates ductility and soundness of welds. The specimen is bent to a specified angle and examined for cracks or other discontinuities.

Calibration

The comparison of a measurement instrument's output to a reference standard of known accuracy. It establishes the instrument's measurement uncertainty and traceability.

Measurement uncertainty

A parameter that characterizes the dispersion of values that could reasonably be attributed to the measurand. It quantifies the confidence in a measurement result.

Expanded uncertainty

The combined standard uncertainty multiplied by a coverage factor, typically k=2 for approximately 95% confidence. It defines an interval about the measurement result.

Traceability chain

An unbroken chain of calibrations linking a measurement instrument to national or international standards. Each link contributes to the measurement uncertainty.

Acceptance sampling

A statistical technique where a sample is inspected to decide whether to accept or reject a lot. It is defined by sample size and acceptance number.

Random sampling

A sampling method where every unit in the lot has an equal chance of being selected. It reduces bias and improves representativeness of the sample.

Data recording

The contemporaneous, legible, and indelible entry of inspection or test data. Entries must be attributable to the person making them and corrections must be traceable.

Control chart

A statistical process control tool that plots a quality characteristic over time with control limits. Points outside the limits indicate special-cause variation.

Nonconformance report

A document that describes a departure from requirements and its disposition. It typically includes description, disposition (use-as-is, rework, repair, reject), and corrective action.

Certificate of conformance

A document attesting that the product meets specified requirements. It is not a substitute for test data unless specifically allowed by the contract.

Material test report

A document that provides the results of chemical and mechanical tests performed on a material. It is often required for traceability and acceptance.

Quality assurance vs. control

Quality assurance includes planned and systematic activities to ensure quality. Quality control includes inspection and testing activities to verify quality.

Ethical conduct in inspection

The requirement for honesty, impartiality, and avoidance of conflicts of interest. Falsification of records or results is prohibited and undermines safety and quality.