Ultrasonic Inspection Formulas

$V_{L}=\sqrt{\frac{E(1-\mu)}{\rho(1+\mu)(1-2\mu)}}$

Where: V_L = Longitudinal Wave Velocity

E = Modulus of Elasticity

$\rho$ = Density

$\mu$ = Poisson's Ratio

more information: Longitudinal Wave Velocity Calculations

$V_{s}=\sqrt{\frac{E}{2\rho(1+\mu)}}$ or $V_{s}=\sqrt{\frac{G}{\rho}}$

Where:

V_s = Shear Wave Velocity

E = Modulus of Elasticity

$\rho$ = Density

$\mu$ = Poisson's Ratio

G = Shear Modulus

more information: Shear Wave Velocity Calculations

$\lambda=\frac{V}{f}$

$$Where:

$\lambda$ = Wavelength

V = Velocity

F = Frequency

more information: Wavelength Calculations

$\frac{\sin\theta_{I}}{\sin\theta_{R}}=\frac{V_{1}}{V_{2}}$

Where:

$\theta$_I = Angle of the Incident Wave

$\theta$_R = Angle of the Reflected Wave

V1 = Velocity of Incident Wave

V2 = Velocity of Reflected Wave

more information: Refracted Angle Calculations

$Z=\rho V$

$$ Where:

Z = Acoustic Impedance

$\rho$ = Density

V = Velocity

more information: Acoustic Impedance Calculations

$R=\frac{(Z_{2}-Z_{1})^{2}}{(Z_{2}+Z_{1})^{2}}$

Where:

R = Reflection Coefficient

Z1 = Acoustic Impedance of Medium 1

Z2 = Acoustic Impedance of Medium 2

more information: Reflection Coefficient Calculations

$N=\frac{D^{2}}{4\lambda}$ or $N=\frac{D^{2}F}{4V}$

Where:

N = Near Field

D = Transducer Diameter

$\lambda$ = Wavelength

V = Velocity

more information: Near Field Calculations Near Field Calculator

$\sin\theta=1.2\frac{\lambda}{D}$ or $\sin\theta=1.2\frac{V}{DF}$

$$Where:

$\lambda$ = Wavelength

D = Transducer Diameter

V = Velocity

F = Frequency

more information: Beam Spread Calculations Beam Divergence Calculator

$\Delta I(dB)=20\text{log}\frac{P_{2}}{P_{1}}$

Where:

dB = Decibel

P1 = Presure Amplitude 1

P2 = Presure Amplitude 2

more information: dB Gain or Loss Calculations