Interactive tools — inputs on the left, live visualization on the right
The wavelength scales with wave speed — a faster material yields longer wavelengths at the same frequency. The animation shows the spatial pressure pattern in each medium. Compressions move rightward; the ratio λ₂/λ₁ = c₂/c₁.
Must be ≤ material thickness
Position the transducer face this distance above the material surface.
The longer path in the faster solid "uses up" focal length equivalent to
mp × cₛ/cₚ mm of water path.
cₚ default 1495 m/s ≈ water at 23 °C
(±3 m/s per °C).
Inspect at or beyond N for stable, predictable amplitude response. In the near field, constructive/destructive interference causes irregular amplitude variations that complicate flaw sizing.
Enter the total round-trip time from the A-scan (transducer face to reflector and back). The result is the one-way depth. Divide by 2 because the pulse travels down and back.
Typical α (dB/mm/MHz): steel 0.3–1.5, aluminum 0.2–0.8, CFRP 1–5, HDPE 2–5, water 0.002. Coarse-grained castings can be 10× higher than wrought alloys.
Default: water → steel (L-wave). For shear-wave wedge inspection use c₂ = 3200 m/s. “TIR” = total internal reflection (incident angle exceeds first critical angle).
Default: water / steel. R and T are intensity coefficients (sum to 100%). A large impedance mismatch means most energy reflects — explaining why couplant is critical.
Half-angle θ½ is from the acoustic axis to the −6 dB pressure edge. Full beam spread = 2 × θ½. Larger diameter or higher frequency concentrates the beam. Near-field distance N is shown for context.
Calculates longitudinal (cL) and shear (cS) wave speeds from elastic constants. Useful when measuring new alloys or composites where tabulated values are unavailable.
Computes crack height from the time difference between tip and base diffraction signals. Based on: a = cosθ × (Δt × v) / 2
Longitudinal wave speed, density, and acoustic impedance at room temperature.
| Material | cL (m/s) | cS (m/s) | ρ (kg/m³) | Z (MRayl) | α (dB/mm/MHz) |
|---|---|---|---|---|---|
| Steel (carbon) | 5900 | 3200 | 7800 | 46.0 | 0.5–1.5 |
| Aluminum 6061 | 6320 | 3130 | 2700 | 17.1 | 0.2–0.8 |
| Titanium Ti-6Al-4V | 6070 | 3110 | 4430 | 26.9 | 0.3–1.0 |
| Water (20°C) | 1480 | — | 998 | 1.48 | 0.002 |
| Water (23°C) | 1495 | — | 997 | 1.49 | 0.002 |
| Glycerin | 1920 | — | 1260 | 2.42 | 0.05 |
| HDPE | 2500 | 900 | 950 | 2.38 | 2–5 |
| CFRP (0° fiber) | ~7000 | — | 1550 | ~10.9 | 1–5 |
| Glass (borosilicate) | 5640 | 3280 | 2230 | 12.6 | 0.1 |
| Copper | 4700 | 2260 | 8900 | 41.8 | 0.4 |
| PZT-5A | 4350 | — | 7750 | 33.7 | — |
| Air (20°C) | 343 | — | 1.21 | 0.0004 | high |
Values are approximate — always measure material-specific properties for critical inspections.