21
Nitrous Oxide Failsafe System—Check Before Each Use
Note:
Be sure O
2
and N
2
O are connected to your MXR and the line pressure for both gases
is 50 PSIG (which is standard).
1. Turn the Total Flow knob to the right (clockwise) until the pointer on the knob hits the stop and
then turn the % N
2
O Concentration knob to the right (clockwise) until the pointer on the knob
hits the stop.
2. Turn the % N
2
O concentration knob counter-clockwise until the pointer is at the left edge of
the “eyebrow” above the knob.
There should be no flow of N
2
O indicated by the digital
display or the flow tube indicator.
This is a check of the static position of the Nitrous Oxide
Failsafe System valve.
Note:
A momentary low flow of N
2
O (about 1 L/min for about a second) may be seen if the %
N
2
O concentration knob is turned to zero before turning the Total Flow knob to zero. This is
N
2
O gas trapped between the Nitrous Oxide Failsafe System valve and the concentration
knob valve and is a normal occurrence.
No other N
2
O flow should be observed.
3. With the % N
2
O concentration knob still set to the left eyebrow position, turn the Total Flow
knob until the display reads a flow of 6 L/min total flow. Turn the %N2O concentration knob
until display reads %N2O 50. You should observe an equal amount of N
2
O flowing, by equal
height ball float positions, while gradually turning the Total Flow knob. The digital display will
track 50% and changing total flow.
4. Interrupt the flow of O
2
. This will check the dynamic status of the Nitrous Oxide Failsafe
System valve. This can be done by either disconnecting the Oxygen hose from the wall or
shutting off the Oxygen at the tank.
The Nitrous Oxide flow should drop as the Oxygen
flow decreases, stopping completely before the Oxygen float drops to the bottom
.
5. If the unit detects a failsafe failure (high N2O percentage), the display will read “FAILSAFE /
TURN OFF N2O SOURCE / SERVICE IS REQUIRED”. The display will flash and an audible
alarm will sound. This message will continue to be displayed in sequence unless the percent
of Nitrous drops.
W
ARNING
:
If the Nitrous Oxide Failsafe System
fails to perform as indicated, do not
use this product prior to repair.
Improper function of this safety
feature may permit Nitrous Oxide to
flow independently of the flow
control knob, potentially allowing
Nitrous Oxide to flow to the patient
without Oxygen.