Ultrasonic Testing(UT)

A group of analysis techniques used to evaluate the condition of materials, components, and assemblies without causing damage or altering their serviceability. NDE methods detect surface and subsurface flaws, measure wall thickness, characterize material properties, and assess the integrity of welds and joints. Common NDE methods include ultrasonic testing (UT), radiographic testing (RT), magnetic particle inspection (MPI/MT), liquid penetrant testing (PT), visual testing (VT), eddy current testing (ECT), and acoustic emission testing (AE).

A measured wall thickness value obtained at a CML using non-destructive examination techniques, typically ultrasonic thickness gauging. Thickness readings are the primary quantitative data for calculating corrosion rates and remaining life of static equipment. Each reading is recorded with the CML identifier, measurement date, measured value, measurement technique, and the technician.

A designated, permanently marked point on equipment where thickness measurements or other condition assessments are taken at regular intervals. CMLs (also called TMLs — Thickness Measurement Locations) are positioned at locations where degradation is expected to be most severe or most representative — areas of high velocity, turbulence, impingement, deadlegs, injection points, and heat-affected zones. Each CML has a unique identifier and documented coordinates.

A qualitative rating of the probability that an inspection activity will correctly identify and characterize the damage present in the inspected equipment. Inspection effectiveness is categorized from A (Highly Effective — high probability of detecting the damage) through E (Ineffective — virtually no chance of detection). The rating depends on the inspection technique used, the skill of the inspector, the coverage area, and the damage mechanism being sought.