Oxygen Ratio Controller (Orc) Adjustment - Dräger Narkomed 2B Service Manual

NM2B
5.5

Oxygen Ratio Controller (ORC) Adjustment

NOTE: See Procedure 5.5A for low flow ORC (P/N 4113229) adjustment.
5.5.1
5.5.2
5.5.3
5.5.4
5.5.5
5.5.6
5.5.7
5.5.8
5.5.9
5.5.10
5.5.11
5.5.12
5.5.13
5.5.14
5.5.15
5.5.16
Rev. F
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ADJUSTMENT AND CALIBRATION PROCEDURES (continued)
Remove the rear cover of the flowmeter housing.
Connect a calibrated oxygen monitor to the fresh gas outlet.
Disconnect the pipeline hoses.
Open the oxygen and nitrous oxide cylinder valves.
Set the System Power switch to ON.
Close the O and N O flow control valves.
2 2
Set the O flow control valve to 10 l/min.
2
Set the N O flow control valve to 10 l/min.
2
Set the O flow control valve to 800 ml/min for one (1) minute. Verify
2
that the O concentration indicates 21% to 29% O
2
Decrease the oxygen flow rate.
If the nitrous oxide does not stop when the oxygen flow is between
325 and 350 ml per minute, loosen the adjusting screw locknut and
turn the adjusting screw (counter-clockwise to decrease N
clockwise to increase N
Repeat steps 5.5.6 thru 5.5.11 until no further adjustment is needed.
Adjust the oxygen flow to a point where the nitrous oxide flowmeter
indicates 10 liters per minute.
The oxygen concentration should be between 21% and 29% oxygen.
Slowly decrease the oxygen flow to 800 ml/min. The nitrous oxide flow
should decrease proportionally, and the oxygen concentration should
remain between 21% and 29% oxygen.
Reduce the O flow to 500 ml/min. Verify that the N
2
than or equal to 600 ml/min.
5-15
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O flow). Tighten the locknut.
2
.
2
O flow,
2
O flow is greater
2