Maintenance Schedule - Hach ORBISPHERE 51 Série Manuel D'utilisation Simplifié

1. Push the maintenance tool (square sides upmost) as far down as possible over the new sensor spot.
Continue to push down on the tool and turn gently until the square sides of the tool and the square slots of the
sensor spot engage. The tool should then drop into position.
2. Make sure the sensor collar is as far down as it will go, so that the top of the collar is aligned with the base of
the sensor head.
3. Take the combined maintenance tool and sensor spot and place it in the end of the sensor.
4. Turn the tool clockwise to screw in the new sensor spot, finger tight. Do not over-tighten. Once secure, pull off
the maintenance tool.

8.3 Maintenance schedule

Service includes membrane replacement and external cleaning to restore the original sensor
sensitivity. This means low running costs and down time reduced to a minimum.
The membrane needs to be replaced once or twice a year depending on application conditions. This
can be tailored accordingly.
Note: If you are not familiar with ORBISPHERE sensor servicing, your Hach representative will be glad to assist
you
8.4 Testing the sensor condition
Periodically, inspect visually the sensor head for any deposits. Rinse it under clean tap water, and
dry with a clean tissue.
To verify the sensor, check measurements against a known standard sample value:
• If reading deviation is ±1% of the expected value, no action needs to be taken.
• If deviation exceeds ± 1%, perform a new calibration.
• If deviation exceeds 10% of the original values, replace the membrane.
Carry out the maintenance in a clean dry place in order to avoid damaging the sensor's precision components,
and also to prevent water or humidity from getting into the sensor.
C A U T I O N
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