Ultrasonic Displays• B scan

The End View Display

B

Ultrasonic Displays• A scan

The CRT (Cathode Ray Tube) display

The Horizontal axis :Represents time base / beam path length / distance / depth

The Vertical axis : Represent the amount of sound energy returned to the crystal

Ultrasonic Displays• C scan

The Plan View Display

C

Ultrasonic Displays• D scan

The Side View Display

D

Pulse Echo Technique

• Single probe sends and receives sound

• Gives an indication of defect depth and dimensions

• Not fail safe

Defect Position

No indication from defect A (wrong orientation)

AB

B

Through Transmission TechniqueTransmitting and Transmitting and receiving probes receiving probes on opposite sides on opposite sides of the specimenof the specimen

Tx Rx

Presence of defect Presence of defect indicated by indicated by reduction in reduction in transmission signaltransmission signal

No indication of No indication of defect locationdefect location

Fail safe method

Through Transmission Technique

Advantages• Less attenuation• No probe ringing• No dead zone• Orientation does not

matter

Disadvantages• Defect not located• Defect can’t be

identified• Vertical defects

don’t show• Must be automated• Need access to both

surfaces

Transmission with ReflectionRT

Also known as:Also known as:

Tandem TechniqueTandem Technique or or

Pitch and Catch TechniquePitch and Catch Technique