20
VI. DIRECTIONS FOR USE
Read instructions completely before operating flowmeter device.
Note: The steps listed below provide a basic functional description of
the flowmeter usage. A training course that emphasizes a practical,
hands-on approach combined with instructions on safe techniques for
administration of nitrous oxide-oxygen conscious sedation is recom-
mended before use of this flowmeter.
Reference flowmeter diagrams on pages 8 or 12 to locate control knobs for appropriate
flowmeter model.
1. Turn on unit and open valves on top of both the N
2
O and O
2
“in-use” tanks.
2. Using Flow Knob, set oxygen flow rate to desired delivery level.
Note: When the N
2
O is set at 0 and the Total Flow Knob is turned to the
on position, the N
2
O ball might move rapidly from the bottom of the
N
2
O flow tube and then immediately return to its resting place at the
bottom of the flow tube. This is a normal occurrence and not an indica-
tion of malfunction.
3. Set % N
2
O Knob to desired percent level.
4. Adjust the total flow rate to the patient by turning the Flow Knob as follows:
Turn the Flow Knob in a counter-clockwise direction to increase flow rate and in a
clockwise direction to decrease flow rate. Total flow rate is the sum of the N
2
O flow
rate and the O
2
flow rate (Total flow rate = N
2
O flow rate + O
2
flow rate).
The numbers shown on the N
2
O Knob represent “% N
2
O of Total Flow.” These
numbers are a guide to assist the doctor in adjusting the N
2
O flows. Accutron rec-
ommends the doctor always use O
2
and N
2
O flow rates indicated in the flow tubes
to calculate the N
2
O and O
2
percentages. % N
2
O of Total Flow is calculated using the
following formula:
% N
2
O =
N
2
O Flow Rate
x 100
(See chart for calculating
N
2
O Flow Rate + O
2
Flow rate
% N
2
O on p. 21)
5. When the procedure is nearing completion and the patient is placed on O
2
only,
make the following adjustments:
Turn the % N
2
O Knob to zero and turn the Flow Knob in a counter-clockwise
direction to increase O
2
flow.
6. When the procedure is complete, turn the Flow Knob fully in a clockwise
direction and make certain the unit is off.
7. At the end of each day turn off gas supply at the tanks. For 2-cylinder and 4-
cylinder models, close N
2
O cylinders and run N
2
O through flowmeter until
trapped gas is gone and gauge reads empty. Turn off O
2
cylinders and run O
2
gas until O
2
gauge reads empty.