SUUNTO HELO2 - Manual (Page 67)

DECOMPRESSION DIVE, ABOVE CEILING.
NOTE DOWNWARD POINTING ARROW, ER WARNING
AND ALARM. YOU SHOULD IMMEDIATLY (WITHIN
3 MINUTES) DESCEND TO OR BELOW CEILING.
In addition, an Error warning (Er) reminds you that you have only three (3) minutes to
correct the situation. You must immediately descend to, or below, the ceiling.
If you continue to violate the decompression, the dive computer will go into a permanent
Error Mode. In this mode, the instrument can only be used as a depth gauge and timer.
You must not dive again for at least 48 hours (refer to Section 5.6. Error conditions).
6.2. Diving in MIXED GAS mode
The MIXED mode is the first dive mode available in Suunto HelO2. The mode is used
when diving with air or with oxygen- or helium-enriched gas mixes.
6.2.1. Before diving in the MIXED GAS mode
If set to the MIXED GAS mode, the correct oxygen and helium percentage of the gas
in your cylinders must always be entered into the computer to ensure correct inert gas
and oxygen calculations. The dive computer adjusts its mathematical inert gas and
oxygen calculation models accordingly. The dive computer will not accept fractional
percentage values of oxygen and helium concentration. Do not round up fractional
percentages. For example, 31.8% oxygen should be entered as 31%. Rounding up
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