Ultrasonic Testing Formula
ULTRASONIC TESTING (UT) USEFUL FORMULAE
1. Velocity of Ultrasonic Waves in a medium (V) = f x l
OR
W here f = Number of cycles per second is called frequency. Measured in ‘Hertz’. Abbreviated as ‘Hz’. One Hertz is equivalent to One cycle per second l = Distance covered in one cycle is wavelength
V= Velocity of Ultrasonic wave inside the medium in ‘mm/s’
2. A coustic Impedance (Z) = V x r
W here:
Z=
Acoustic Impedance
r=
D ensity
V=
Velocity
3. R eflection Coefficient
W here:
R = Reflection Coefficient
Z1 = A coustic Impedance of Medium 1
Z2 = A coustic Impedance of Medium 2
®
TRINITY NDT
Material Testing & NDT I Training& Certification I Consulting
Visit us: www.trinityndt.com
Page 1 of 4
2011-12
For refererence only. ‘TINT’ is not responsible for errors and omissions in the data if any.
4. Transmission coefficient
T = 4 Z1Z2/ (Z1+Z2)2
W here:
R = Reflection Coefficient
Z1 = Acoustic Impedance of Medium 1
Z2 = Acoustic Impedance of Medium 2
5. Longitudinal Wave Velocity
W here:
VL =
E=
r= m= Longitudinal Wave Velocity
Modulus of Elasticity
Density
Poisson's Ratio
6. Shear Wave Velocity
W here:
Vs =
E=
r= m= G=
Shear Wave Velocity
Modulus of Elasticity
Density
Poisson's Ratio
Shear Modulus
7. Refraction - Snell's Law: That is the ratio of sine of the angle to the respective wave velocities are proportional.
Where: qI = qR =
V1 =
V2 =
Angle of the Incident Wave
Angle of the Reflected Wave
Velocity of Incident Wave
Velocity of Reflected Wave
®
TRINITY NDT
Material Testing & NDT I Training& Certification I Consulting
Visit us: www.trinityndt.com
2011-12
Page 2 of 4
For refererence only. ‘TINT’ is not responsible for errors and omissions in the data if any.
8. Near Field
Where:
N
D l V
=
=
=
=
Near Field
Transducer Diameter
W avelength
Velocity
9. Beam Spread Half Angle
Where: l D
V
F
=
=
=
=
1. Velocity of Ultrasonic Waves in a medium (V) = f x l
OR
W here f = Number of cycles per second is called frequency. Measured in ‘Hertz’. Abbreviated as ‘Hz’. One Hertz is equivalent to One cycle per second l = Distance covered in one cycle is wavelength
V= Velocity of Ultrasonic wave inside the medium in ‘mm/s’
2. A coustic Impedance (Z) = V x r
W here:
Z=
Acoustic Impedance
r=
D ensity
V=
Velocity
3. R eflection Coefficient
W here:
R = Reflection Coefficient
Z1 = A coustic Impedance of Medium 1
Z2 = A coustic Impedance of Medium 2
®
TRINITY NDT
Material Testing & NDT I Training& Certification I Consulting
Visit us: www.trinityndt.com
Page 1 of 4
2011-12
For refererence only. ‘TINT’ is not responsible for errors and omissions in the data if any.
4. Transmission coefficient
T = 4 Z1Z2/ (Z1+Z2)2
W here:
R = Reflection Coefficient
Z1 = Acoustic Impedance of Medium 1
Z2 = Acoustic Impedance of Medium 2
5. Longitudinal Wave Velocity
W here:
VL =
E=
r= m= Longitudinal Wave Velocity
Modulus of Elasticity
Density
Poisson's Ratio
6. Shear Wave Velocity
W here:
Vs =
E=
r= m= G=
Shear Wave Velocity
Modulus of Elasticity
Density
Poisson's Ratio
Shear Modulus
7. Refraction - Snell's Law: That is the ratio of sine of the angle to the respective wave velocities are proportional.
Where: qI = qR =
V1 =
V2 =
Angle of the Incident Wave
Angle of the Reflected Wave
Velocity of Incident Wave
Velocity of Reflected Wave
®
TRINITY NDT
Material Testing & NDT I Training& Certification I Consulting
Visit us: www.trinityndt.com
2011-12
Page 2 of 4
For refererence only. ‘TINT’ is not responsible for errors and omissions in the data if any.
8. Near Field
Where:
N
D l V
=
=
=
=
Near Field
Transducer Diameter
W avelength
Velocity
9. Beam Spread Half Angle
Where: l D
V
F
=
=
=
=