Hach Orbisphere 410 Basic User Manual page 21

O sensor calibration
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The O sensor needs to be calibrated after each sensor service. Wait at least 30 minutes after
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mounting a new membrane before re-calibrating. The sensor is in contact with either:
• Air at atmospheric pressure (In Air)
• O at known concentration (Direct value). The gas can be dissolved or not.
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In air calibration
This calibration procedure places the O
reference against which to calibrate.
Dry the sensor thoroughly, before placing the sensor storage cap under tap water. Shake off any
excess water, but leave a few drops inside the cap. Verify that the screw-on protection cap is in place
on the sensor head. If you use a Dacron mesh inside the protection cap, make sure it is dry before
attempting to calibrate. Then, loosely place the storage cap back on the sensor, holding it in place
with a few turns of its collar.
Set the calibration parameters accordingly and press calibrate.
Direct calibration
This procedure calibrates the oxygen sensor against a liquid sample containing a known level of
dissolved O flowing through the sample line.
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The instrument displays the sensitivity of the sensor as a percentage of the sensitivity determined
when calibration was last performed.
Set the calibration parameters accordingly and press calibrate.
O sensor calibration
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The sensor is either in contact with:
• Air at atmospheric pressure (In Air)
• O at known concentration (Direct Value). The gas can be dissolved or not.
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The procedure is the same as for the O
measures O during calibration. The O
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behaves in O . As a different voltage is used at the anode to measure O
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measurement takes a long time to stabilize. To facilitate the follow up after an "O
negative values can be displayed.
TC sensor calibration
Calibration of the measured gas
1. Before initiating a calibration process, the calibration parameters must be set by pressing on the
Modify button. The last calibration parameters are memorized, so this step can be ignored if the
correct parameters are already set. Similarly, if only the calibration value has changed, then this
can be updated directly instead of pressing the Modify button.
Option
Gas Phase
Gas unit type
Gas unit
Liquid
Value
sensor in water-saturated air, to provide a known oxygen
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sensor. In the case of the "In air" calibration, the sensor
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coefficient is deduced taking into account how the sensor
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Description
Select liquid or gas (direct calibration only)
Partial, fraction or dissolved (dissolved is for calibration in a liquid only)
The list of available units depends on unit type selected above.
Select as appropriate.
Enter the gas concentration according to the value in the calibration media.
and O , the O
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in air" calibration,
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English 21