Phased Array Ultrasonic Testing (PAUT) & Time of Flight Diffraction (ToFD)

Advanced Ultrasonic Solutions for Code-Driven Infrastructure Projects

Phased Array Ultrasonic Testing (PAUT) and Time of Flight Diffraction (ToFD) represent the cutting edge of ultrasonic NDT offering highly accurate, volumetric inspection capabilities essential for today’s complex infrastructure and code-driven fabrication work.

At AEIS, we deploy PAUT and ToFD primarily to meet the stringent requirements of AWS D1.1 (Structural Welding Code – Steel) and AWS D1.5 (Bridge Welding Code), particularly in steel bridge fabrication, airport terminal construction, and rail infrastructure. Our team of certified PAUT operators is trained not only in advanced ultrasonic methods but also in the application of these technologies for NYSSCM, DOT, and public agency QA/QC programs.

Phased Array Ultrasonic Testing (PAUT):

PAUT uses multiple small ultrasonic transducers in a probe, which are fired in sequence with varying time delays to steer and focus the ultrasonic beam.

This allows for:

• Inspection at multiple angles using a single probe
• Generation of real-time B-scan, S-scan, C-scan, and A-scan images
• Enhanced detection of flaws near geometric discontinuities (e.g., weld roots, toes, and heat-affected zones)

Time of Flight Diffraction (ToFD):

ToFD uses a pitch-and-catch setup to detect diffracted waves from crack tips. It is especially effective for:

• Crack sizing and monitoring over time
• Detecting lack of fusion, incomplete penetration, and root defects in critical welds
• Rapid scanning of longitudinal weld seams and pressure-retaining structures

Why AEIS for PAUT and ToFD:

• AWS D1.1 & D1.5 Specialists with public agency experience
• Certified Technicians operating under ASNT EBC-accredited procedures
• Custom Scanning Plans for each weld joint and material profile
• Detailed Reports & Imaging suitable for engineer review, DOT approval, and quality archives