Hanna Instruments HI 9829 - Manual (Page 82)

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D.O. Sensor Maintenance
I•Before sevicing, rinse the probe with tap water.
• If a more thorough cleaning is required, clean the probe body and sensor with
the supplied brush or a non-abrasive detergent. If any deposit scales the
sensor, gently brush the sensor surface with the supplied brush, while paying
attention to not damage the plastic body. Do not use the brush on the mem-
brane.
For a top performance probe, it is recommended to replace
the membrane every 2 months and the electrolyte monthly.
While the cap is off, inspect the sensor internal electrodes.
• If the zinc anode (Concentric metal electode than surrounds internal stem)
appears coated with a white substance or is dull, clean by gently wiping with
the plastic scouring pad that is included in the maintenance kit.
To replace the membrane cap or electrolyte proceed as follows:
• Unscrew the membrane by turning it counterclockwise.
• Rinse a spare membrane with some electrolyte while shaking it gently. Refill
with clean electrolyte.
• Gently tap the cap over a surface to ensure that no air bubbles remain
trapped. Avoid touching the membrane.
• With the sensor facing down, completely screw the cap clockwise. Some
electrolyte will overflow.
EC Sensor Maintenance
• After every series of measurements, rinse the probe with tap water.
• If a more thorough cleaning is required, clean the sensor with the supplied
brush or a non-abrasive detergent. Ensure that the two cylindrical holes in the
sensor are free of foreign material.
EC/Turbidity Sensor Maintenance
• After every series of measurements, rinse the probe with tap water.
• If a more thorough cleaning of the sensor is required, clean the EC cylindrical
holes in the sensor with the supplied brush or a non-abrasive detergent. En-
sure that the two cylindrical holes are free of foreign material.
• Gently remove any material that is attached to the face of the turbidity sensor
taking care to not scratch the optical windows. Use a soft cloth and non-
abrasive detergent.
• If there are cracks or scratches on the optical windows, the EC/turbidity sensor
must be replaced.