EUTECH INSTRUMENTS CD 650, Инструкция по эксплуатации

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Figure 62: Positioning
of O-ring & Membrane
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 2.5 cm/sec.
The permeability of the membrane to oxygen varies greatly with
temperature. Therefore compensation is needed for this variation. The DO
probe comes with an in-built Temperature Compensation for the
membrane variation.
3.2.2 Probe Care
Under typical operating conditions, the probe should last for several years.
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 in clean water and wipe it with a soft
cloth or paper to avoid any hardening of deposits. If growth develops on
the probe, use a disinfecting chemical to clean.
3.2.3 Membrane Housing Replacement
Replacement of the membrane cap housing/ membrane 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.
Your new DO probe comes with replacement membrane
housing. To order more replacement membrane housing,
see the “Accessories” section page.
To replace the membrane cap (with pre-installed
membrane)
1. Replacement is much easier with single membrane
housing. Unscrew the old membrane cap housing.
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.