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PAUTAdvanced SpecialistOnline / Self-Paced

Phased Array UT (PAUT) Focal Law & Scan Plan Fundamentals

Advanced course on electronic beam steering, sectorial scanning (S-scan), linear scanning (E-scan), Time Corrected Gain (TCG) normalization, and encoder scan plans under ASME Section V Article 4.

NDT Exchange Global Open Academy 40 Hours (Self-Paced) ASNT SNT-TC-1A / ISO 13588

Total Tuition & Exam Fee

100% FREE

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💡 Plain-English Summary (In Layman's Terms)

Beginner Friendly

No prior physics or engineering degree required — here is what this technique actually does in the real world.

While conventional ultrasound uses a single sound crystal (like pointing a single spotlight), Phased Array uses an array of 16 to 64 tiny crystals in a single probe. By firing these crystals with microsecond timing delays, you can sweep the sound beam in real-time across multiple angles (like an airport radar dish sweeping the sky) without moving the probe by hand. You get an instant cross-sectional picture of the inside of the weld.

What You Will Understand in Plain Terms:

✓Radar for Welds: How firing dozens of microscopic sound crystals in sequence electronically steers a beam from 40° to 70°.

✓Instant 2D Pictures: How sectorial scans (S-scan) show an immediate medical-style cross section of defects in the weld bead.

✓Encoder Tracking: Connecting an electronic wheel to the probe so every millimeter of metal scanned is recorded with GPS-like precision.

✓Precision Sizing: Measuring the exact height and depth of buried cracks by catching tiny sound waves pinging off their sharp tips.

Common Defects You'll Learn to Spot (Everyday Terms):

🔍 Lack of Sidewall Fusion (Unbonded weld sidewall)🔍 Incomplete Penetration (Weld didn't reach the bottom)🔍 Slag Inclusions (Trapped glass/mineral crust)🔍 Hydrogen Cracking (Microcracks from moisture)

Open PAUT Focal Law Calibration Guide

Course Syllabus & Training Modules

Structured curriculum designed according to ASNT SNT-TC-1A & ISO 9712 requirements with layman explanations.

Multi-Element Transducers & Acoustic Beam Steering

💬 In simple terms: Teamwork of tiny crystals: how microsecond delays steer and focus sound

Physics of multi-element phased arrays, pitch, element width, and active aperture calculations.

Array anatomy: 16, 32, or 64 tiny crystal elements packed into one handheld probe casing

Constructive interference: How ripples from multiple crystals combine to form one concentrated beam

Focal laws: How software programs microsecond delays (nanoseconds) across channels to angle the beam

Electronic focusing: Squeezing sound down to a tight waist at the exact depth of the weld root

Sectorial & Linear Scan Plan Configurations

💬 In simple terms: Designing the scan plan: ensuring 100% of the weld metal gets illuminated by sound

Designing sound path beam overlays to ensure 100% volumetric coverage of complex weld bevels.

Sectorial Scans (S-scan): Sweeping like a radar fan from 40° to 70° to hit bevel angles square-on

Linear / Electronic Scans (E-scan): Stepping the beam straight ahead for fast thickness corrosion maps

Wedge selection: Choosing the angled plastic block with tungsten carbide pins to protect against wear

Ray tracing: Simulating sound rays on a computer screen to prove no defect can hide in blind spots

Sensitivity Calibration, TCG & Encoder Mapping

💬 In simple terms: Calibrating the array so every crystal is balanced and positions are tracked by wheel

Field normalization of element gains, velocity, wedge delay, and optical shaft encoder setup.

Dead element check: Making sure none of the 64 tiny micro-wires or crystals are cracked or dead

TCG (Time Corrected Gain): Equalizing signals so a defect 50mm deep looks just as bright as one 10mm deep

Wheel encoders: Linking a rolling measuring wheel to the scan so data is pinned to exact pipe inches

Data fusion: Viewing A-scan (echo), B-scan (side view), C-scan (top-down map), and S-scan (fan view) simultaneously

Data Analysis, Defect Sizing & Code Compliance

💬 In simple terms: Reading the final scan: measuring crack height, length, and comparing to code limits

Accurate flaw length and through-wall height sizing according to ASME Sec V Mand. App VIII.

Geometric root echoes vs. real cracks: Never confusing the natural root contour with a dangerous defect

Tip diffraction sizing: Catching the faint whisper of sound pinging off a crack's sharp upper and lower tips

Length measurement: Using standard 6 dB drop rules on C-scan maps to measure defect length

ASME Section VIII & B31.3 acceptance: Classifying defects as acceptable rounded items or rejectable linear flaws

Course Instructor

Robert Frost, Level III #189204

Certified NDT Level III inspector with over 15 years of field inspection and industrial training experience.

Hosting Academy

NDT Exchange Global Open Academy

Worldwide (Digital Learning)

admissions@ndtexchange.com

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