Ei Electronics Ei208DWRF Instructions Manual page 8

2.4 Pre-Alarm
When the Alarm detects over 43 ppm CO the red light flashes in accordance with
Table B-1 & B-2. This helps locate CO leaks as the CO Alarm gives an indication
straight away.
(Without this feature the CO level would need to be at 43 ppm CO for typically
72 minutes for an alarm sound to be given). Note the Pre-Alarm signal may be
triggered by CO coming for example, from cooking with gas, from car engines or
from nearby barbecues. This is usually not a concern, unless the pre-alarm signal
persists until the Alarm sounds and the CO source is unknown.
The display models will display CO concentrations greater than 10ppm in
accordance with Table B-1 & B-2.
NOTE: The CO Alarm may sound if cigarette smoke is blown into it, or aerosols
are released nearby.
2.5 CO Alarm Memory
The CO Alarm memory is an important feature of the CO Alarm where even if the
house is unoccupied during an alarm condition it warns the homeowner that the CO
Alarm has previously detected CO gas and been in alarm. The memory feature has
two operation modes:
- memory indication for 24 hour period after alarm.
- memory recall on demand
24 hour memory indicators: After alarm, the RED light will flash at different rates
every minute (approx) depending on the level of CO detected - see Table C.
Memory recall on demand: To review the memory status after initial 24 hours,
press and hold the test button, the red led will flash in accordance to Table C.
Display models will show the peak level of CO measured.
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