Cns Toxicity Display - Cressi Archimede II Manual De Instrucciones

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DANGER: As a safety measure, in order to avoid the
involuntary setting of nitrox mixtures at depths where they
might be toxic (excessive PO2), Archimedes II does not
allow the mixture change if the new mixture's PO2 is higher
than the one set on the computer (1.4 bar = default value).
The maximum PO2 alarm will sound if you attempt to set
nitrox mixtures at depth.
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DANGER: Should both mixtures' FO2 values be set and
no dive carried out, the computer will store the set values in
the memory until the current day's midnight, when they
both will be reset on a value of 99%.
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DANGER: After 10 minutes from the end of a dive, the
computer resets the mixtures' FO2 on a safety value of
99%, waiting for the user to set the correct values relating to
the new mixtures. The display will show "--" in the place of
FO2%, as in (picture 12b).
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DANGER: Always check, prior to diving, the FO2 and
PO2 values of both set mixtures! While on the surface, it is
possible to check their values, by depressing button A ( ),
which visualizes the previously set parameters.
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DANGER: do not dive with bottles containing Nitrox
mixtures, without having personally checked their oxygen
percentage.
Related topics:
• 2.3.1. - program parameters setting
• 3.3.1. - PO2 setting
• 3.3.2. - Nitrox mixture/s oxygen fraction F02 setting
• 3.3.4. - CNS toxicity display.
• 3.3.5. - PO2 alarms.

3.3.4. - CNS toxicity display

Archimedes II computer is display a graph of the Central
Nervous System toxicity level as to the oxygen level. Its toxi-
city level is bound with the oxygen's partial pressure and
with the exposure to high oxygen partial pressures (PO2).
Picture 15 represents the UFDS display's 8 pixels column,
which shows the increasing accumulated oxygen quanti-
ties. When all 8 pixels light up, 100% of the maximum tole-
rance allowable to the CNS has occurred and serious dan-
ger of an oxygen intoxication exists.
It is important to understand, monitor, and control the oxy-
gen toxicity level.
In order to reduce the risk of oxygen toxicity, Archimedes II
displays a graph which is easy to be read in any situation.
When the oxygen level reaches warning values, next to the
maximum allowable toxicity (corresponding to 7 of 8 lighted
pixels), the graph starts flashing along with the display, and
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an alarm starts sounding which lasts 15 seconds, showing
the proximity of a CNS toxicity level.
When the eighth pixel lights up, a second (100%) alarm
starts sounding. At this time the graph and display flash and
the alarm sounds, until the diver surfaces, letting the oxygen
partial pressure decrease.
When the eighth pixel turns off and the graph stops flashing,
the alarm will be entered in the Logbook.
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