ALGAE AND OTHER,GROWTHS ON SENSOR : Algae or other growths may develop on the tip if the sensor is
left immersed in certain samples. These growths may interfere with accuracy and should be removed. Dip the
tip of the sensor into a beaker containing hydrochloric acid (not sulfuric or nitric) of approximately 6N to 8N
strength (50-60Z solution) for a few moments and then thoroughly flush with clean tap water. Experience with
local conditions will determine the frequency of such cleaning. This may also be done before use as a
preventive measure if the sensor
is used when slime may grow on it.
Long storage of the sensor in a beaker of distilled water may cause a build-up of bacterial slime. This can be
prevented by adding a few drops of Formaldehyde to the water in which the sensor is stored. If this is not
practical, remove the slime as described above. If hydrochloric acid is not available, the slime may be
removed with wet paper or cloth and a detergent. Exercise care to avoid loosening or damaging the
PREVENTIVE MAINTENANCE : To avoid malfunction and possible breakdown, the preventive maintenance
checks listed in the table below should be performed on a regular basis.