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The programme looks at two cases of the importance of reliability. These are the reliability of components and the reliability of a system. After establishing the ideas of expected life, random fai...lure and infantile failure, film shot at Mullard, Southampton is used to illustrate some of the methods used for endurance testing of semi-conductor components. The tests shown are: Life testing under, continuous electrical loading; Electrical load test under extremes of temperature and humidity; Low temperature storage test; Mechanical shock test; Vibration test and examination of items which have failed to ascertain cause of failure. A further series of tests is used to estimate expected life at normal temperatures. The second half of the programme, Roger Phipps, Principal Development Engineer (Instruments) Design and Development Branch, B.E.A., discusses tie standard of reliability required of an automatic blind landing system. and outlines ways of using redundancy to achieve these standards.
Metadata describing this Open University video programme
Module code and title: T100, The man-made world: a foundation course
Item code: T100; 10
First transmission date: 19-03-1972
Published: 1972
Rights Statement:
Restrictions on use:
Duration: 00:24:04
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Producer: Nat Taylor
Contributors: Roger Harrison; R Phipps
Publisher: BBC Open University
Keyword(s): Automatic blind landing system; Components; Endurance testing; Expected life; Infantile failure; Mullard; Random failure; Semi-conductor components; System; Telephone exchange
Footage description: Shots of a BEA Trident airliner making an automatic landing in inclement weather. Harrison discusses the need to know system reliability. He uses the Trident's "Autoland" system as an example. Harrison looks at reliability of individual parts of a system. As an example he plots the reliability curve of automobile tyres on a graph. Both wear out and random failure are plotted. Harrison uses a "Peas in a box with a hole in it" analogue to show what is meant by random failure. Harrison introduces a film on endurance testing shot at Mullard's Reliability Division, Southampton. Film shows: Components being tested for reliability. Components coming off the production line are shown being tested for uniform quality. Shots of integrated circuit undergoing high temperature endurance testing, low temperature endurance testing, and vibration endurance test. Shots of a failed circuit, undergoing microscopic examination to determine reason for failure (End of film) Harrison tells why this is important. Shot of a Logic circuit for a G.P.O. telephone exchange being tested at a series of increasing temperatures. Harrison plots the results of the test on a graph to show that the reliability demanded by G.P.O. can be predicted for these components R.C.J. Phipps with a model of a jet aircraft explains how the autoland system works. He uses the model to demonstrate the landing manoeuver. Phipps discusses the concept of introducing redundancy to improve system reliability. Using a mag. board diagram he demonstrates that an increase in the number of subsystems results in increased reliability of the total system but that chance of failure of any one subsystem also increases. Phipps explains, with the aid of models, several system formats which would be possible for an "autoland" system. He explains the systems in use in the BAC 111, VC 10 and Trident. Shots of a Trident landing in fog. Shots of flight deck and crew. Credits.
Master spool number: 6LT/70462
Production number: 00521_2524
Videofinder number: 2155
Available to public: no