– 20 –
2. Check n
2
o:
If no nitrous oxide is being supplied,
the unit emits visual and acoustic information signals.
this also happens if the pressure is too low or there is a
measurement section failure. the visual “Check n
2
o” sig-
nal appears in the top right of the sedation display and
the n
2
o bar on the bottom right is shaded red. A “Check
n
2
o gas supply” pop-up window appears and must be
acknowledged. In addition, an acoustic information sig-
nal is audible. this event is recorded in the error memory
log. Pure oxygen can still be administered to the patient,
however the sedative effect will wear off without the ni-
trous oxide. the settings in the Sedation menu can still
be changed. the alert disappears once n
2
o flows across
the measurement section again. the check n
2
o informa-
tion signal of the unit is muted using the mute button. If
the cause is an empty nitrous oxide cylinder, replace the
cylinder. If the alert has been caused by something else,
please contact the Service team.
6.3 Information signals and error codes
Information signals
the information signals are shown in the top right of the
display.
1.
check
o
2
:
If no oxygen is being supplied, the unit
emits
visual and acoustic
information signals. this also
happens if the pressure is too low or there is a measure-
ment section failure. the visual “Check o
2
” signal appears
in the top right of the sedation display and the o
2
bar on
the bottom right is shaded red. A “Check o
2
gas supply”
pop-up window appears and must be acknowledged. In
addition, an acoustic information signal is audible. this
event is recorded in the error memory log. the sedation
continues, but without n
2
o and therefore without gas
flow. Accordingly, the unit has a nitrous oxide lock: the
unit switches off the nitrous oxide flow immediately if
there is a lack of o
2
. the patient will not suffocate if the
oxygen cylinder is empty and the practitioner forgets to
remove the mask. Instead, the emergency valve on the
Bag t opens and the patient breathes in the ambient
air. the alert disappears once o
2
flows across the meas-
urement section again. the check o
2
information signal
cannot be muted. the o
2
signal sounds in greater inter-
vals when the mute button is pressed. If the cause is an
empty oxygen cylinder, replace the cylinder. If the alert
has been caused by something else, please contact the
Service team.
Fig. 19: Sedation display, check o
2
Fig. 20: Sedation display, check n
2
o
3. o
2
mi
n
imum flow 1l/min.:
Visual and acoustic sig-
nals: the o
2
minimum flow is 1 l/min. the mixture ad-
ministered can never contain less than 1 litre of o
2
. this
is displayed visually in the top right. the total mixture
volume is never less than 3 l/min.
Fig. 21: Sedation display, o
2
minimum flow 1l/min.