Hach GA2 00 Series, User Manual

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4.3 Membrane replacement and sensor head cleaning
C A U T I O N
Chemical exposure hazard. Obey laboratory safety procedures and wear all of the personal
protective equipment appropriate to the chemicals that are handled. Refer to the current safety data
sheets (MSDS/SDS) for safety protocols.
A sensor recharge kit is required as it contains all the components necessary for this membrane
replacement and sensor head cleaning process. Refer to
Sensor recharge kit on page 9.
Note: It is advisable to perform this procedure with the plastic sensor base installed so as to avoid any damage to
the connection socket and also to provide a suitable stand for the sensor when required.
1. Hold the main body of the sensor and unscrew the protection cap locking washer by turning
counter-clockwise. Remove it from the sensor and put to one side.
2. Pull/twist off the protection cap and put to one side. If you are using a protection cap with a grille,
then remove the Dacron
®
mesh from inside the cap and discard it.
3. Hold the sensor with the membrane facing down to avoid spilling any electrolyte, then carefully
unscrew the old cartridge. Drain the old electrolyte into a sink and flush away. Discard the old
cartridge and membrane. Remove the cotton washer and silicone disc from the top of the anode
and discard.
4. Rinse the sensor head under a tap for 15 seconds to remove any remaining electrolyte and shake
dry. With a soft tissue gently clean around the guard area (indicated right) and then wipe off any
excess moisture from the sensor to ensure all parts are completely dry. Repeat this rinse and dry
process with the protection cap.
5. Clean the anode using the cleaning tool supplied. Place the tool over the sensor head. Clean by
rotating the cleaning tool over the sensor head for a few seconds,
in a clockwise direction only .
6. Remove the tool and tap it face down on a flat work surface to remove any powdery deposit.
Check the sensor to ensure that all deposits have been removed from the anode. If not, repeat
step 5. until the anode regains its bright silver appearance.
22 English