Hach ORBISPHERE 51 Serie Manuel D'utilisation Simplifié page 23

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.
2
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.
7.4.2.3 O sensor calibration
3
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.
3
The procedure is the same as for the O
measures O during calibration. The O
2
behaves in O . As a different voltage is used at the anode to measure O
2
measurement takes a long time to stabilize. To facilitate the follow up after an "O
negative values can be displayed.
7.4.2.4 H sensor calibration
2
Potential Fire and Explosion Hazard. Handle H
The recommended method is at known concentration (Direct Value). The gas can be pure H
mixture of H with an inert gas (e.g. a mixture of H
2
user in the calibration parameter window. The sensor is in contact with the calibration gas (Direct
Value) in gas phase at atmospheric pressure.
Make sure the H concentration used for calibration is within the acceptable range for the membrane. Hach Lange
2
recommends the following calibration gas/inert gas combinations for calibrating with the following membranes.
See the Sensor Maintenance Manual for further details on membrane specifications:
Membrane
7.4.3 TC sensor calibration
7.4.3.1 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
sensor. In the case of the "In air" calibration, the sensor
2
coefficient is deduced taking into account how the sensor
3
gas with great care!
2
2956A
2952A
2995A
29015A
Description
Select liquid or gas (direct calibration only)
W A R N I N G
/N ). The known concentration is entered by the
2 2
N O T I C E
Recommended calibration gas
and O , the O
2 3 3
in air" calibration,
3
1% H / 99% N
2 2
10% H / 90% N
2 2
100% H
2
100% H
2
English 23
or a
2