Available online
Description
The programme examines some applications of ultrasonics in imaging.
The programme examines some applications of ultrasonics in imaging.
| Module code and title: | ST291, Images and information |
|---|---|
| Item code: | ST291; 15 |
| First transmission date: | 22-09-1977 |
| Published: | 1977 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:00 |
| Note: | Production number FOUS724T |
| + Show more... | |
| Producer: | Tony Jolly |
| Contributors: | David Crecraft; Barrie Jones |
| Publisher: | BBC Open University |
| Keyword(s): | Foetus in womb; Hologram; Metal fatigue; Oscilloscope; Photoelastic effect; Ultrasound imaging |
| Subject terms: | Ultrasonics |
| Footage description: | Barrie Jones introduces the programme. He blows first into a recorder and then a dog whistle. The sinusoidal waveforms for each sound are imaged behind him. David Crecraft explains and demonstrates an apparatus used to obtain ultrasonic images from a glass block specimen which contains internal flaws. He switches on the machine and explains the principles involved. The resulting trace is shown on an oscilloscope. Both the ultrasonic waves and the flaws can be seen in the glass block. Crecraft examines the signal, displayed on an oscilloscope, from a transducer mounted on the glass block. He explains how this signal is obtained. Crecraft goes on to explain and demonstrate how the bubble flaws are picked up on the oscilloscope. Crecraft then demonstrates an acoustic flaw detector on a steel block specimen which has had a hole drilled in one side. Ian Lowe uses a water and sponge model to examine and explain the principles involved in imaging, acoustically, a human foetus. Film of a pregnant woman being acoustically scanned in order to obtain an image of the foetus. David Crecraft obtains an acoustic hologram of a steel block in a tank of water. He goes on to demonstrate how this hologram is reconstructed to give an image of the specimen. Using several caption diagrams, photographs and oscilloscope displays, Crecraft explains how the original ultrasonic hologram is recorded. Ian Lowe sums up. |
| Master spool number: | DOU2411 |
| Production number: | FOUS724T |
| Videofinder number: | 2126 |
| Available to public: | no |
