Operating malfunctions
39
acoustic signal. This consists of a sequence of tones that vary depending on
the nature of the alarm and priority. The sequence of tones is indicated in the
following table by the letters forming each tone pitch (c, a, f, e). The C is an
octave above c.
Display
Priority
(Display)
Acoustic
Cause
Length of
trigger
Measure
Circuit dis-
connec-
tion
High
c a f - a f
The device
detects a fall
in pressure in
the exhala-
tion system.
The tube sys-
tem has prob-
ably become
detached.
10 sec
Checks the tube
system's connec-
tions.
Mains fail-
ure
Moderate
Beep (for
2 minutes)
The device
no longer has
power supply.
Direct
Check the power
supply connection.
Tube
blocked
Moderate
c a f
The device
detects an
obstruction in
the tube sys-
tem.
10 sec
Check the tube
system for any
potential block-
ages.
Remove any poten-
tial blockages.
Restart the therapy.
