4
CONCENTRATION CONTROL KNOB VALVE
–
CHECK MONTHLY
Set the Concentration Control Knob to 50%, and Flow
Control Knob to 2 to 3 L/min. The ball indicators will
be at about the same height (If not, refer to
Monthly
Calibration Check
section for the procedure on
checking the accuracy of the meter.). Turn the
Concentration Control Knob to zero. The N
2
O flow
should drop to zero. You essentially perform the
check at the end of every procedure when you
oxygenate the patient with 100% O
2
.
POWER OXYGEN FLUSH
CHECK MONTHLY
(O
2
SUPPLY PRESSURE AT 50 PSIG)
Disconnect the corrugated rubber tubing from the bag
tee outlet (Figure 1, Item 11). With both control knob
valves OFF, depress the power (O
2
) flush button while
blocking the flow from the front of the bag tee. For
proper operation, the gas reservoir bag should fill
within about 5 seconds. Also test for bag / rubber
goods leak following steps 1 through 6.
Quick Test to Check Reservoir Bag / Rubber
Goods for Leaks
1. With the flowmeter, bag tee and
Porter
rubber
goods in place, remove the nosepiece and one of
the two plastic connectors from the Porter rubber
goods.
2. With the other plastic connector, join the two
duplex hoses together making a closed system.
3. Taking care not to fill the bag too much (bag could
burst), open the oxygen control valve until the
reservoir bag starts to over-
inflate or “balloon”,
then close the valve.
4. Observe the reservoir bag for five minutes.
5. The bag should stay inflated. If so, the test has
been successful and there are no excessive leaks.
If the bag does not stay inflated, the reservoir bag
or rubber goods have an excessive leak. Replace
any parts that leak and retest until results are
successful.
6 .
Disconnect one of the duplex hoses from the
plastic connector and re-install the nosepiece.
BAG TEE
The Bag Tee assembly features a Non-rebreathing
Valve and an Emergency Air Intake located on the
Bag Tee (no carbon dioxide buildup). The emergency
air intake has a valve that allows room air to be
inhaled into the breathing circuit by the patient. A
breathing bag is attached to the metal portion of the
flowmeter.
Bag Tee Installation to Flowmeter: Screw knurled
seal down tight onto flowmeter making sure the rubber
washer is inside the seal nut. When tight, the bag tee
should not rotate.
NON-REBREATHING VALVE
CHECK MONTHLY
With unit turned OFF, disconnect the corrugated rubber
tubing from the Rubber Goods and breathe into the
corrugated tubing connected to the bag tee. You should
not be able to fill the bag with exhalation gas. If the bag
fills, the system’s Non-Rebreathing Valve is not
functioning properly and should be replaced.
EMERGENCY AIR VALVE
CHECK MONTHLY
With unit turned OFF, disconnect the corrugated rubber
tubing from the Rubber Goods and draw air with your
mouth through the corrugated tubing connected to the
bag tee. You should be able to draw ambient air through
the Emergency Air Valve (the gas bag may have to fully
collapse first). Air going through the valve sounds
different than normal gas flow.
MONTHLY CALIBRATION CHECK
The MXR Flowmeter is designed to maintain its
accuracy and performance without routine user
maintenance being required. The flowmeter tubes and
ball floats are very resistant to accuracy changes over
time such that the direct readings of the L/min on the
scales maintain their accuracy. However, the user can
check the relative accuracies of the % concentration and
total flow valve system by performing a simple check.
A calibration check of the % concentration can be done
by setting the % concentration knob to 50% and the flow
control knob to 3 to 4 L/min. Check to see if the tube
readings are within 0.5 L/min of each other. Servicing is
indicated if the readings are out of this tolerance.
NOTE:
Adequate and safe conscious sedation can be
achieved even if the % concentration is outside of the
listed tolerance, since tube scale accuracies are
maintained. However, a change in the %
concentration calibration is an indication of overall
flowmeter condition. Porter servicing is available,
including recalibration, pressure testing, internal
component checking and replacement, and final
factory
testing
by
contacting
your
authorized
distributor. It is advisable, on a two (2) year cycle, to
have the MXR Flowmeter factory checked and
serviced.
