time of useful consciousness


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time of useful consciousness

The period between the loss of oxygen supply (at altitude) and the inability of the individual to function efficiently.
References in periodicals archive ?
When such tasks start taking excessive lengths of time to be done or are done poorly, it is usually a sign that the "Time of Useful Consciousness" has been exceeded and that the mask should be replaced.
There are two ways of measuring this altitude/risk relationship: effective performance time and time of useful consciousness. Depending on the reference source, these two terms are often considered synonymous, but there are subtle distinctions between them.
Since then, naval aviators have been experiencing the symptoms of hypoxia and viewing its detrimental effects as time of useful consciousness approaches zero.
Time of useful consciousness without [O.sub.2] at FL200 is usually 30 minutes, but by FL250 it's only 3-5 minutes.
The time of useful consciousness or TUC (the period from the exposure to an O2-deprived environment, to the time when useful function is lost) at FL280 is roughly three minutes.