LaMotte DO 6 Dissolved Oxygen Meter - Manual (Page 41)

possible to measure the partial pressure of oxygen in the sample at a given
temperature.
Since the DO in the sample is consumed by the cathode it is essential that a
new sample must flow past the membrane of the probe to prevent the
occurrence of false readings. The probe uses very little oxygen for its
measurement. This enables it to function correctly with liquid movement as
low as 2 inch/sec across membrane.
The permeability of the membrane to oxygen varies greatly with temperature.
Therefore compensation is needed for this variation. The DO6 probe comes
with an in-built Temperature Compensation for the membrane variation.
8.1 Probe Care
Proper care and maintenance will help you receive the maximum probe life
and ensure more accurate readings.
Since any deposits on the membrane surface act as a barrier to oxygen diffusing
through the membrane, the membrane must be cleaned at regular intervals to
assure maximum reliability.
After using the probe, rinse the probe with clean water and wipe it with a soft
cloth or paper to avoid any hardening of deposits if necessary. If growth
develops on the probe, use a disinfecting chemical to clean.
NOTE: Although the membrane is strong and not easily damaged, wipe it
gently while cleaning it. If the membrane is damaged or torn, the probe will no
longer function.
There are no special probe storage requirements.
8.2 Pre-Membraned Caps Replacement
Replacement of the pre-membraned cap is required only when you cannot
calibrate the probe, or if the membrane is damaged.
Typical membrane damages are punctures or wrinkles caused during
measurements or cleaning.
To order replacement probe components or a replacement probe, see Section
“Accessories” on page 48.
8.3 To replace the probe pre-membraned cap.
1. Unscrew counter clockwise the pre-membraned cap from the probe sensing
tip and discard.
2. Wash the probe under running water.
3. Mount the nozzle tip onto the syringe provided. Fill the syringe with the
refill solution through the tip of the plastic bottle.
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