Pressure Effects; Humidity Effects; Calibration Errors And Error Codes - Maxtec MAXO2+ A Operating Manual & Instructions For Use

3.3 Pressure Effects

Readings from the MAXO
The partial pressure is equal to the concentration times the absolute pressure.
Thus, the readings are proportional to the concentration if the pressure is held
constant. Therefore, the following are recommended:
» Calibrate the MAXO
» If sample gases flow through tubing, use the same apparatus and flow rates when
calibrating as when measuring.

3.4 Humidity Effects

Humidity (non-condensing) has no effect on the performance of the MAXO
other than diluting the gas, as long as there is no condensation. Depending on
the humidity, the gas may be diluted by as much as 4%, which proportionally
reduces the oxygen concentration. The device responds to the actual oxygen
concentration rather than the dry concentration. Environments where
condensation may occur are to be avoided since moisture may obstruct
passage of gas to the sensing surface, resulting in erroneous readings and
slower response time. For this reason, the following is recommended:
» Avoid usage in environments greater than 95% relative humidity.
» When used in a breathing circuit, place the sensor upstream of the humidifier.
HELPFUL HINT: Dry sensor by lightly shaking moisture out, or flow a dry gas at two
liters per minute across the sensor membrane.

4.0 CALIBRATION ERRORS AND ERROR CODES

The MAXO + analyzers have a self test feature built into the software to detect
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faulty calibrations, oxygen sensor failures, and low operating voltage. These are
listed below, and include possible actions to take, if an error code occurs.
E02: No sensor attached
MAXO +A: Open unit and disconnect and reconnect sensor. Unit should
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perform an auto calibration and should read 20.9%. If not, contact Maxtec
Customer Service for possible sensor replacement.
MAXO +AE: Disconnect and reconnect external sensor. Unit should perform
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an auto calibration, and should read 20.9%. If not, contact Maxtec Customer
Service for possible sensor replacement or cable replacement.
E03: No valid calibration data available
Make sure unit has reached thermal equilibrium. Press and hold the
Calibration Button for three seconds to manually force a new calibration.
E04: Battery below minimum operating voltage
Replace batteries.
CAL Err St: O
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Wait for displayed oxygen reading to stabilize, when calibrating the device at
100% oxygen.
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+ are proportional to the partial pressure of oxygen.
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+ at the same pressure as the sample gas.
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Sensor reading not stable
866.4.Maxtec www.maxtec.com
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