58
Fluoride Electrodes
a.
Moisten the end of the Q-tip with water and dip it in the alumina polishing powder to pick up a
small amount of the powder.
b.
Rub the polishing powder onto the fluoride crystal in a circular motion and moisten the tip if
necessary to produce a liquid consistency more than a paste.
c.
Polish the electrode for about 30 seconds and examine the tip for a shiny surface, repeat if
necessary.
d.
Rinse the electrode with distilled water and soak the electrode in a low ppm Calibration solution
for a few minutes.
e.
Perform a Two Point Calibration.
Other Solid State electrodes, Bromide, Cadmium, Chloride, Copper, Lead, Sulfide, Silver…
a.
Place a few drops of distilled water on the blue polishing strip to wet the polishing surface.
b.
Hold the electrode with the sensing surface facing up.
c.
Slide the polishing strip back and forth across the electrode tip, the sensing tip will be abraded
and a new electrode surface will be generated.
d.
Polish the electrode for about 30 seconds and examine the tip for a shiny surface, repeat if
necessary.
e.
Rinse the electrode with distilled water and soak the electrode in a low ppm Calibration solution
for a few minutes.
f.
Perform a Two Point Calibration.
8.3.7
D
ISSOLVED
O
XYGEN
C
ARTRIDGES
The Teflon membrane of the Dissolved Oxygen sensors is fragile and should be cleaned using a soft cloth or an
artist style paint brush while rinsing with a stream of water. Dilute dish washing detergents can be used to
remove oily films. Solvents are not recommended as they could diffuse through the membrane and harm the
electrode. Strong acid/alkaline solutions should not harm the electrode but should only be used as a last resort
before replacing the electrode.
8.3.8
TRITON
DO80
D
ISSOLVED
O
XYGEN
The Triton DO80 sensor should receive maintenance on a regular basis. The maintenance interval should be
determined empirically as it will depend on the installation conditions and the nature of the media being
measured. The interval should be no greater than every two months.
Maintenance Procedure
The typical procedure would include;
Cleaning the sensor
Check the measuring function:
o
Remove the sensor from the medium.
o
Clean and dry the sensor/membrane.
o
After about 10 minutes in air, measure the oxygen saturation index (without recalibration).
o
The measured value should be at 100 ± 4 % SAT
If necessary, replace a defective membrane or one which cannot be cleaned any more.
Recalibration, if necessary.
