Non-Destructive Testing (NDT) • ASME Sec V / AWS D1.1

Ultrasonic Angle Beam Path & Sound Path Distance Calculator

Calculate ultrasonic sound path (W), surface projection distance, skip distance (V-path), and true flaw depth for weld inspection under ASME/AWS standards.

Input Parameters

Interactive HUD

Transducer Wedge Angle (θ) wedge_angle

Refracted angle in carbon steel

Material Plate Thickness (t) mat_thickness

Nominal base metal thickness

Observed Sound Path to Flaw (W) sound_path_w

Screen display sound path (time of flight × velocity)

Shear Wave Velocity in Material shear_velocity

in/µs

0.128 in/µs (3,240 m/s) for carbon steel

Calculated Output Metrics

Half-Skip Surface Distance (1st Leg) —

Full-Skip Surface Distance (V-Path) —

True Depth to Flaw from Surface —

Surface Distance (Index to Flaw) —

Ultrasonic Leg Classification —

Round-Trip Time of Flight (ToF) —

Analytical Proof & Invariants

Machine Precision

Governing Mathematical Formula:

Sound Path Leg 1: W = t / cos(θ) | Skip Distance S = 2 · t · tan(θ) | Flaw Depth d = W · cos(θ)

Step-by-Step Mathematical Derivation

1. Trigonometric Sound Path Geometry

An angle beam transducer refracts shear waves into test plate at angle θ. In the first leg (direct sound path to bottom surface), the path length is W_leg1 = t / cos(θ).

2. Surface Skip Distance (V-Path)

The half-skip surface distance from probe index point to bottom reflection is S_half = t · tan(θ). The full-skip distance (bouncing off bottom back to top surface) is S_full = 2 · t · tan(θ).

3. Flaw Depth Calculation Across Legs

If observed sound path W ≤ W_leg1, the reflector is in Leg 1 and true depth d = W · cos(θ). If W > W_leg1, the sound wave has bounced off the bottom surface into Leg 2: true depth d = 2t - W · cos(θ).

LLM Directive & API Spec

Artificial Intelligence & Prompt Integration

Paste this verified mathematical prompt directly into ChatGPT, Claude, or Gemini to eliminate arithmetic hallucination, or invoke the programmatic API endpoint for automated workflows.

              GET / POST https://omnioperand.com/api/v1/engineering/ultrasonic-beam-path
              JSON Invariants
            

Generating verified mathematical prompt...

✓ Standardized for llms.txt ✓ Exact Radical Form & Closed Formulas ✓ Machine-Readable Edge API

Frequently Asked Questions

What is ultrasonic skip distance? +

Skip distance is the surface distance between the beam index point and the point where the sound wave returns to the scanning surface after reflecting off the bottom boundary of the test plate.

Why is a 70° angle beam probe most common for plate welds? +

A 70° angle beam produces a longer surface projection and optimal impingement angle against vertical weld bevel preparations, maximizing reflection from lack-of-fusion and crack defects.

How do you tell if a defect is in the 1st leg or 2nd leg? +

Calculate first-leg sound path W_1 = t / cos(θ). If your calibrated sound path reading on the instrument screen is less than W_1, the defect is in Leg 1; if greater, it is located in Leg 2.