Maxtec MaxO2+ Bedienungsanleitung Seite 5

1.4 Component Identification
3-DIGIT LCD DISPLAY — The 3-digit liquid crystal display (LCD) provides direct readout of
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oxygen concentrations in the range of 0 – 105.0% (100.1% to 105.0% used for calibration
determination purposes). The digits also display error codes and calibration codes as
necessary.
LOW BATTERY INDICATOR — The low battery indicator is located at the top of the display
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and is only activated when the voltage on the batteries is below a normal operating level.
"%" SYMBOL — The "%" sign is located to the right of the concentration number and is
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present during normal operation.
CALIBRATION SYMBOL —
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display and is timed to activate when a calibration is necessary.
ON/OFF KEY — This key is used to turn the device on or off.
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CALIBRATION KEY — This key is used to calibrate the device. Holding the key for
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more than three seconds will force the device to enter a calibration mode.
SAMPLE INLET CONNECTION — This is the port at which the device is connected to
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determine oxygen concentration.
1.5 Max-250 Oxygen Sensor
The Max-250+ oxygen sensor offers stability and extra life. The Max-250+ is a galvanic, partial
pressure sensor that is specific to oxygen. It consists of two electrodes (a cathode and an anode),
a teflon membrane and an electrolyte. Oxygen diffuses through the teflon membrane and
immediately reacts at a gold cathode. Concurrently, oxidation occurs electrochemically at the
lead anode, generating an electrical current and providing a voltage output. Electrodes are
immersed in a unique gelled weak acid electrolyte which is responsible for the sensors long life
and motion insensitive characteristic. Since the sensor is specific to oxygen, the current
generated is proportional to the amount of oxygen present in the sample gas. When no oxygen
is present, there is no electrochemical reaction and therefore, negligible current is produced. In
this sense, the sensor is self-zeroing.
NOTE: The Max-250 oxygen sensor indirectly contacts the patient through the breathing gas
pathway.
2 OPERATING INSTRUCTIONS
2.1 Getting Started
2.1.1 Protect Tape
Prior to turning on the unit, a protective film covering the threaded sensor face must be
removed. After removing the film, wait approximately 20 minutes for the sensor to reach
equilibrium.
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The calibration symbol is located at the bottom of the
2.1.2 Automatic Calibration
After the unit is turned on it will automatically calibrate to room air. The display should be stable
and reading 20.9%.
CAUTION: The device will assume a percent oxygen concentration when calibrating. Be sure to
apply 100% oxygen, or ambient air concentration to the device during calibration or the device
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will not calibrate correctly.
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To check the oxygen concentration of a sample gas: (after the unit has been calibrated):
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1. Connect the Tygon tubing to the bottom of the analyzer by threading the barbed
adapter onto the oxygen sensor. (FIGURE 1, B)
2. Attach the other end of the sample hose to the sample gas source and initiate flow of
the sample to the unit at a rate of 1-10 liters per minute (2 liters per minute is
recommended).
3. Using the "ON/OFF"
4. Allow the oxygen reading to stabilize. This will normally take about 30 seconds or
more.
2.2 Calibrating the MaxO2+ Oxygen Analyzer
NOTE: We recommend use of medical grade USP or >99% purity oxygen when calibrating the
MaxO2+.
The MaxO2+ Analyzer should be calibrated upon initial power-up. Thereafter, Maxtec
recommends calibration on a weekly basis. To serve as a reminder, a one-week timer is started
with each new calibration. At the end of one week a reminder
bottom of the LCD. Calibration is recommended if the user is unsure when the last calibration
procedure was performed, or if the measurement value is in question. Start calibration by
pressing the Calibration key for more than 3 seconds. The MaxO2+ will automatically detect
if you are calibrating with 100% oxygen or 20.9% oxygen (normal air).
DO NOT attempt TO CALIBRATE TO ANY OTHER CONCENTRATION.
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FIGURE 1
key, make sure the unit is in the power "ON" mode.
icon will appear on the
ENGLISH