Factors Influencing Accurate Readings; Elevation Changes; Temperature Effects; Pressure Effects - Maxtec MAXO2+A Industrial Manual & Operating Instructions

4.0 FACTORS INFLUENCING ACCURATE READINGS

4.1 Elevation Changes

• Changes in elevation result in a reading error of approximately 1% of reading
per 250 feet.
• In general, calibration of the instrument should be performed when elevation at
which the product is being used changes by more than 500 feet.

4.2 Temperature Effects

The MAXO +
will hold calibration and read correctly within ±3% when in thermal
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equilibrium within the operating temperature range. The device must be thermally
stable when calibrated and allowed to thermally stabilize after experiencing
temperature changes before readings are accurate. For these reasons, the
following is recommended:
• For best results, perform the calibration procedure at a temperature close to
the temperature where analysis will occur.
• Allow adequate time for the sensor to equilibrate to a new ambient temperature.
CAUTION: "CAL Err St" may result from a sensor that has not reached thermal
equilibrium.

4.3 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.
• The MAXO +
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atmospheres absolute. Calibration or operation above this pressure is beyond
the intended use.

4.4 Humidity Effects

Humidity (non-condensing) has no effect on the performance of the MAXO
8
M A N U F A C T U R E D B Y M A X T E C , I N C .
+ are proportional to the partial pressure of oxygen.
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+
at the same pressure as the sample gas.
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oxygen sensor has been tested at pressures up to two
+
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