Xylem IOLINE TRIS COMPATIBLE pH ELECTRODES - Handbuch

Instruction manual for
SCHOTT
®
Instruments
IoLine electrode series
Preparation and general
The electrodes of the IoLine series except the micro versions
(IL-MICRO-XXX) are delivered in a special watering vessel
with a bayonet lock. This vessel can also be used as storage
equipment between measurements. Micro electrodes are
delivered in a screwable glass tubing, due to their smaller
diameter
Before you pull out the electrode of the watering vessel with
the bayonet lock the lock must be unscrewed by turning
anticlockwise with line of sight on top of the electrode head.
Then the seal is released and the electrode is loosened. The
vessel contains watering solution L911. This solution
conditions the glass membrane and causes a faster response.
Therefore the vessel s
h ould be refilled with L911, alternatively
L300 (3 mol/l potassium chloride solution) can be used. In the
electrolyte chamber (chamber 3 in the sectional drawing) is
filled potassium chloride solution 3 mol/l. The filling level must
be at least as high as the inner diaphragm and the electrolyte
level should be 5 cm above the measured solution. This
electrolyte can be changed if required according sample. For a
stable measurement the conductivity of the solution should be
at least 10 mS/cm. The bridge electrolyte must be free of
silver ions.
The colored iodine containing solutions are incorporated in a
closed system and do not need to be refilled or changed.
For calibration and measurement the refill port slider in the
head of the electrode must be opened, to assure the flow of
electrolyte and stable and fast recording of the signal. The
diaphragm must immerse in the solution.
Measuring the pH-value
Please also note the usage instructions of the measuring
device during calibration and measurement. In order to
minimize inaccuracies in the measurement results, electrodes
used under extreme conditions or at the limits of the specified
usage range should be calibrated more frequently. For
accurate calibration, we recommend the use of our steam
sterilized, certified buffer ampoules to DIN 19 266.
Always use fresh buffer solution.
Storage and maintenance
Electrodes should be stored at a temperature of between 0 and
40 °C. Depending on storage conditions (temperature and air
humidity), the irrigation fluid in the cap may dry out
prematurely.
In this case, the electrode must be irrigated for at least 24
hours in L911 or 3 mol/l potassium chloride solution before it is
ready for use. Crystals in the electrolyte area can be dissolved
by warming in a water bath. The electrolyte solution should
then be replaced, and the correct potassium chloride
concentration checked.
Cleaning
Dirt and contamination at the pH-membrane and diaphragm
will lead to measurement inaccuracies.
• The glass membrane can be cleaned by rubbing off with a
fluff-free cloth soaked in ethanol.
• Coatings and deposits can be removed with diluted
mineral acids (e.g. hydrochloric acid 1 : 1).
• Organic contamination with the aid of suitable solvents.
• Grease can be removed with tenside solutions.
• Proteins can be removed with hydrochloric pepsine solution
(cleaning solurion L 510).
• After cleaning, rinse off the electrodes with distilled water, do
not rub dry.
• Ceramic diaphragms blocked from outside can be restored
to working order by carefully rubbing down with fine
sandpaper or a diamond file. Take care not to scratch the
pH glass membrane!
• Platinum diaphragms must not be subjected to any
mechanical treatment. Rinsing (e.g. vacuuming) may be
followed by chemical cleaning (e.g. with dilluted hydrochloric
acid).
• After cleaning, rinse off the electrodes with distilled water, do
not rub dry.
Quality
Every electrode must meet the strict quality requirements of
final testing. The durability depends mainly on the usage
conditions. Extreme conditions include for example high or
frequently fluctuating temperatures, strong acids and caustic
solutions and heavily contaminated solutions attack electrodes.
Hydrofluoric acid, sodium hydroxide and hot phosphoric acid
corrode glass.
Further Information
Further information can be found in the Laboratory catalogue
and in the Process electrodes catalogue of SI Analytics GmbH
or you will find more tips in the operating instruction of your
meter.
Subject to technical amendment.
GA_IoLine_d_us_T814147_111123
SI Analytics GmbH
Hattenbergstrasse 10
55122 Mainz
Germany
Phone +49 (0) 6131/66 5116
Fax +49 (0) 6131/66 5001
E-Mail: [email protected]
www.si-analytics.com
bridge electrolyte
chamber 3
head with integrated
refill hole
Internal
diaphragm
picture of an
exemplary electrode
sectional drawing
Also with integrated temperature sensor
diaphragm
Internal buffer pH glass
membrane
derivation element
reference electrolyte
chamber 2
refill port slider
staorage reservoir
for refernece
electrolyte
chamber 1
temperature sensor
reference element