Jenway 3540 - Manual (Page 69)

Maintenance & Troubleshooting
8.1 General
The Model 3540 is designed to give optimum performance with minimum maintenance. It is
only necessary to keep the external surfaces clean and free from dust. To give added
protection when not in use the unit should be disconnected from the mains supply and
covered with the optional dust cover (060 406). For longer-term storage or re-shipment it is
recommended that the unit be returned to the original packing case.
All pH electrodes and conductivity cells should be thoroughly rinsed after use and stored as
detailed in Sections 1.4 and 1.5 (Good Practice Guidelines).
8.2
Cleaning/Re-conditioning of combination electrodes
For general purpose use, combination electrodes can be cleaned with a mild detergent
solution or a commercial glass cleaning solution (provided these are not strongly acidic). The
electrode surface should be wiped with a clean cloth soaked in the cleaning agent, and/or
allow the membrane to stand in the solution until clean. Rinse and repeat as necessary.
Electrodes which have been allowed to dry out should be soaked overnight in warm distilled
water.
Table of Cleaning Agents for Glass Electrodes
Deposit Cleaning
Agent
General deposits Genklene or mild detergent solution
Inorganic coatings Commercial glass cleaning solution (not strongly acidic)
Metal compounds Acid solution, not stronger than 1M
Oil/Grease Complexing agent (EDTA) or suitable solvent
Resins/Lignins Acetone, alcohol or detergent (not strongly acidic)
Proteins (blood, etc) Enzyme solutions (e.g; pepsin in 0.1M HCl)
Stubborn deposits Hydrogen peroxide, sodium hypochlorite or domestic bleach
Note: Solvents such as carbon tetrachloride, trichloroethylene, petroleum, ether, etc,
MUST NOT be used for cleaning electrodes that have a plastic body or a plastic
protective skirt.