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5.2.4. Excessive Water in Circuit
Condition detected
Possible cause
Action to take
Excessive water in
inspiratory circuit due to
rainout.
If in non-heated wire mode, water trap not
at the lowest point of the circuit.
Reposition water trap.
If in heated wire mode, heater wire too
close to temperature probe.
Increase distance from heater wire to
temperature probe so that the distance
is between 25 (1”) and 100mm (4)),
ideally 30mm.
Inspiratory circuit being cooled by air
conditioner.
Shield circuit from air conditioner or use
heater wire circuit.
Chamber control set too high.
Reduce setting.
Maximum permissible peak flow rate of
humidification chamber has been
exceeded.
Use correct chamber. Refer to the operating
instructions for the type of chamber used.
Humidifier chamber tilted.
Ensure chamber is level.
Possibly faulty temperature probe (low
resistance).
Check probe.
Excessive water in expiratory
circuit due to rainout.
Condensation due to cooling in Expiratory
line.
Use dual heated circuit.
Water ejected from
humidification chamber into
Circuit.
Humidification chamber filled beyond
maximum water level line.
Reduce water level.
Maximum permissible peak flow rate of
humidification chamber has been
exceeded.
Use correct chamber. Refer to the operating
instructions for the type of chamber used.
Humidifier chamber tilted.
Chamber should be level.
5.2.5. Low Humidity
Condition detected
Possible cause
Action to take
Low humidity.
Chamber control set to low.
Increase setting.
No water in humidification chamber.
Fill chamber.
Chamber temperature low.
Check chamber temperature setting on
display when humidifier is switched on,
chamber base and heater plate are smooth
and flat and in good contact.
Gas flow rate too high for chamber.
Check maximum flow rate in to chamber
operating instructions.
5.2.6.
Alarms
Condition detected
Possible cause
Action to take
Temperature probe alarm
‘OPEN’ appears on display.
Temperature probe unplugged.
Check connection.
Temperature probe plug dirty.
Clean plug.
Temperature probe faulty.
Replace probe.
Temperature probe alarm
‘A.OPN’ appears on display.
Airway temperature probe open.
Replace probe.
Temperature probe alarm
‘A.SHT’ appears on display.
Airway temperature probe short.
Replace probe.
