Calibrating an Oxygen Instrument

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False oxygen alarms can occur due to changes in barometric pressure (altitude changes) or extreme changes in ambient temperature.

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The ALTAIR Detector is equipped with a feature to allow calibration at pressure and/ or temperature of use.

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Be sure that the instrument is in known fresh air before performing a calibration.

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The ALTAIR Oxygen instrument has the ability to display the current Oxygen level with a press of the TEST button. See "Using the ALTAIR Single Gas Detector" for more details. If this reading is other than 20.8%, a calibration is required in air that is known to be safe.

To enter the calibration mode, make sure you are in fresh, uncontaminated air.

WARNING! 

Do not perform calibration unless you are certain you are in fresh, uncontaminated air; otherwise, inaccurate readings can occur which can falsely indicate that a hazardous atmosphere is safe.

Failure to follow this warning can result in serious personal injury or death.

1.

In normal operating mode, press the TEST button.

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The current Oxygen reading displays.

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See Figure 9 for more details.

2.

When the "TEST" "GAS" "?" displays, press and hold the TEST button to enter calibration.

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"TEST" "CAL" displays

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After three seconds, "FAS" "?" displays asking the user if a fresh air setup/ calibration is desired.

3.

Press the TEST button at the "FAS" "?" screen to perform a calibration at 20.8% O2.

NOTE: This procedure must be performed in fresh, uncontaminated air. Do not breathe on the sensor while performing this function.

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If the sensor successfully calibrates:

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"OK" displays

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If the sensor does not successfully calibrate:

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"ERR" displays.

4.

Wait five seconds.

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The instrument returns to normal operating mode.

5.

If "ERR" displays after calibration, the current settings did not change. Immediately check that:

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The instrument is in fresh, uncontaminated air during the calibration process.

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No one breathes on the sensor during calibration.

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Repeat steps 1 through 6, as necessary.

6.

The display must read "OK"; if "ERR" remains, remove the instrument from service.

7.

Perform a bump test to confirm operation and activate the "√".