YSI Pro2030 - Manual (Page 21)

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Chemical cleaning: Remove the cap membrane and rinse the sensor with
deionized or distilled water. Soak the sensing section of the sensor in a 14%
ammonium hydroxide solution for 2 to 3 minutes or in a 3% ammonia solution
overnight for 8-12 hours (most household ammonia cleaners are typically
around 3%). Rinse heavily in cool tap water followed by a thorough rinsing with
distilled or deionized water. The anode should then be thoroughly wiped with a
wet paper towel to remove the residual layer from the anode. Trapping residual
ammonia under the new membrane cap can quickly tarnish the electrode and/
or give false readings and should therefore be avoided.
After performing a chemical cleaning on the polarographic sensor, lightly sand
the cathode and anode following the mechanical cleaning procedures described
previously.
If this procedure is unsuccessful, as indicated by improper sensor performance,
contact YSI Technical Support or the YSI authorized dealer where you purchased
the instrument.
Galvanic Sensors – Model # 605202
YSI recommends that the Sodium Chloride (NaCl) electrolyte solution and
cap membrane be changed every 2-4 weeks during regular use. In addition, the
electrolyte solution and membrane should be changed if (a) bubbles are visible
under the membrane; (b) significant deposits of dried electrolyte are visible
around the membrane; and (c) if the sensor shows unstable readings or other
sensor-related symptoms.
The Galvanic dissolved oxygen sensor is continuously reducing oxygen even
when the instrument is turned off. This factor allows the sensor to be used with
no warm-up period as soon as the instrument is powered on. However, because
the sensor is “on” all the time, some solid from the oxidation of the zinc anode
will form in the electrolyte within 1-2 weeks of activation. Small amounts of
the solid will generally cause no performance problems, but excessive amounts
may result in jumpy dissolved oxygen readings. The rate of solid formation is
dependent on the type of membrane installed. The formation of solids typically
form more rapidly with 5913 (1.25 mil PE) membrane, and less rapid with 5914
(2 mil PE) membranes.
Chemical cleaning should be performed as infrequently as possible.
First attempt a membrane change and recalibrate. If a new membrane
does not resolve the problem, then proceed with cleaning.
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At the time the cap membrane is changed, YSI recommends that you rinse the
anode and cathode (figure 12) with distilled or deionized water and wipe with
a clean paper towel. If white deposits are evident on the anode after cleaning,
YSI recommends that you remove this material by sanding the anode with
the 400 grit wet/dry sanding disc included in the membrane kit following the
“Mechanical Cleaning” instructions under the Polarographic Silver Anode
maintenance section of this manual. If there are deposits on the cathode, sand
the cathode with the 400 grit wet/dry sanding disc following the maintenance
instructions listed in this manual for the Polarographic Gold Cathode.
If this procedure is unsuccessful, as indicated by improper sensor performance,
contact YSI Technical Support or the YSI authorized dealer where you purchased
the instrument.
sensor storage
SHoRT TERM SToRAGE
The instrument is supplied with a grey calibration/storage sleeve that slides over
the probe guard. The sleeve is used for short-term storage (less than 30 days). Be
sure to keep a small amount of moisture (clean tap water) on the sponge in the
sleeve during storage. This is simply done to maintain a 100% water saturated
air environment which is ideal for short-term sensor storage. The sensors should
not be submerged in water.
LoNG TERM SToRAGE
The dissolved oxygen and conductivity sensors should be stored long term in a
dry state. When storing for more then 30 days, remove the cap membrane and
thoroughly rinse the dissolved oxygen sensor with distilled or deionized water.
once the sensor has been rinsed either blow it dry with compressed air or allow
The Galvanic electrolyte solution will appear milky white after use but
this will not affect the accuracy of the sensor unless there is excessive
build up. The color change is acceptable and normal as long as DO
readings remain stable.
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IMPORTANT: Be sure to: (1) Use only the fine sanding discs provided
and (2) Sand as mentioned in the above procedures. Not adhering to
either of these instructions can damage the electrodes.
WARNING: Do not perform the Polarographic chemical cleaning on
a Galvanic sensor.
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