Holographic Non-Destructive Testing
A single large ultrasonic transducer which sends out ultrasonic waves towards the object under study and it scans the object. The scattered waves from the object from the object waves. A received transducer collects the scattered object wave and converts them into electrical signals. The reference electrical waves are given by the RF oscillator and these object to reference waves are made to interference by the electronic adder. The interference pattern is formed on the fluorescent screen of the cathode photographic film is developed.
The developed photographic film serves as a hologram. The hologram is illuminated by a low power laser like He- Ne laser which acts as the optical reference source. The T.V camera takes the videograph of the 3 D image of the object and it displays on the T.V monitor