Kobold APS-Z User manual

Operating Instructions
for
pH/Redox Electrodes
(Combination Electrodes)
Model: APS-Z/APK-Z/ARS-Z

APS-Z/APK-Z/ARS-Z
page 2 APS-Z/APK-Z/ARS-Z K04/1122
We don’t accept warranty and liability claims neither upon this publication nor in
case of improper treatment of the described products.
The document may contain technical inaccuracies and typographical errors. The
content will be revised on a regular basis. These changes will be implemented in
later versions. The described products can be improved and changed at any time
without prior notice.
© Copyright
All rights reserved.
1. Contents
1.Contents ........................................................................................................ 2
2.Note .............................................................................................................. 3
3.Instrument Inspection .................................................................................... 4
4.Regulation Use ............................................................................................. 4
5.Sensor installation ......................................................................................... 5
6.Calibration and measuring ............................................................................ 6
7.Cleaning ........................................................................................................ 8
8.Maintenance ................................................................................................. 9
9.Service life and warranty ............................................................................. 10
10.Order Codes ............................................................................................... 11
11.Disposal ...................................................................................................... 12
Manufactured and sold by:
Kobold Messring GmbH
Nordring 22-24
D-65719 Hofheim
Tel.: [phone]
Fax: [phone]
E-Mail: [email protected]
Internet: www.kobold.com

APS-Z/APK-Z/ARS-Z
APS-Z/APK-Z/ARS-Z K04/1122 page 3
2. Note
Please read these operating instructions before unpacking and putting the unit into
operation. Follow the instructions precisely as described herein.
The instruction manuals on our website www.kobold.com are always for currently
manufactured version of our products. Due to technical changes, the instruction
manuals available online may not always correspond to the product version you
have purchased. If you need an instruction manual that corresponds to the
purchased product version, you can request it from us free of charge by email
([email protected]) in PDF format, specifying the relevant invoice number and
serial number. If you wish, the operating instructions can also be sent to you by
post in paper form against an applicable postage fee.
The devices are only to be used, maintained and serviced by persons familiar with
these operating instructions and in accordance with local regulations applying to
Health & Safety and prevention of accidents.
When used in machines, the measuring unit should be used only when the
machines fulfil the EC-machine guidelines.
If you encounter difficulties during startup, please do not interfere with the electrode
in any way that is impermissible. By doing so, you could endanger your rights under
the instrument warranty. Please contact your supplier.
 Each electrode is a quality product and is individually tested and packaged.
 Storage should be in a dry room at -5 to +30°C. Because pH and redox
electrodes have limited suitability for storage, we do not recommend storing
them for longer than 6 months.
 All electrodes are provided with a rinsing cap or container for transport and
storage to prevent the sensor elements from drying out.
 The electrode should be kept in a 3mol/l solution of KCl.
 If the electrode has been stored dry for an extended time, however, it must
be conditioned before being used for measurements. For this purpose, the
electrode is immersed in a 3mol/l solution of KCl for about 24 hours.
 The pH-sensitive membrane glass must be handled carefully (no skin
contact, protect against damage, etc.)!
 Make certain that electrical connections and cables are kept clean and dry.
If you send the electrode back, we need a brief description of the fault:
o Electrode cannot be calibrated
o Display is not stable
o Other fault:

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Electrodes must not be allowed to dry out during use or storage!
Do not keep the electrode in distilled water!
3. Instrument Inspection
Instruments are inspected before shipping and sent out in perfect condition.
Should damage to a device be visible, we recommend a thorough inspection of the
delivery packaging. In case of damage, please inform your parcel service /
forwarding agent immediately, since they are responsible for damages during
transit.
Scope of delivery:
The standard delivery includes:
 pH/Redox Electrodes (Combination Electrodes) model: APS-Z/APK-Z/ARS-Z
4. Regulation Use
Any use of the device, which exceeds the manufacturer’s specification, may
invalidate its warranty. Therefore, any resulting damage is not the responsibility of
the manufacturer. The user assumes all risk for such usage.

APS-Z/APK-Z/ARS-Z
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5. Sensor installation
 Electrodes must be installed vertically. The maximum angle to the vertical
is 80°.
 The internal buffer must cover the inside surface of the membrane glass. Air
bubbles in the membrane chamber must be removed by light shaking of the
electrode in the vertical.

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6. Calibration and measuring
Always follow the instructions in the manual for the transmitter you are
using as well!
 When a new pH electrode is placed in operation with a measurement
amplifier, a calibration must be performed.
 Typically, a two-point calibration is required for pH electrodes. Two standard
buffer solutions are required (for example pH 7.0 and 4.0). Usually, the
buffer solutions are selected to bracket the later measurement range.
Rinse off the electrode with water between measurements!
First Step
Connect the pH/redox electrode with the transmitter and immerse it in a buffer or
test solution (for example pH 7.0 or 468 mV).
 With manual temperature entry, adjust the temperature of the buffer solution
on the measuring instrument.
 Wait until the display value for the pH/redox (and temperature) has
stabilized. Then adjust the pH/redox value of the first buffer/test solution on
the transmitter.
Rinse off the pH electrode with deionized water and carefully dry it with a soft cloth.
For redox electrodes the calibration is now complete

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Second step
 Immerse the pH electrode in a second buffer solution (for example pH 4.0
or 10.0) and wait until the display value has stabilized. Then enter the pH
value of the second buffer solution.
 The measuring instrument determines the zero point and slope of the
sensor.
 Rinse off the electrode with deionized water and carefully dry it with a soft
cloth.
 The calibration is complete.

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7. Cleaning
The membrane glass must never be exposed to aggressive or abrasive cleaning
agents (scouring milk, etc.)!
Cleaning the membrane glass must not result in any scratches!
 Impurities that have accumulated on the surface of the membrane glass and
diaphragm must be removed!
 The electrode must be adequately washed off after every cleaning!
 If careful dabbing with a soft moist cleaning tissue proves unsuccessful,
various chemical cleaning methods can be used depending on the type of
impurity:
Type of accumulation Cleaning agent
Lime and metal hydroxide Diluted hydrochloric acid (1-3%)
coatings
Greases and oils Organic solutions (for example ethanol) or
a solution containing a surfactant
(dishwashing detergent, etc.)
Protein Pepsin in diluted hydrochloric acid
Accumulation Cleaning mixture consisting of
containing sulfides hydrochloric acid and thiourea
Inorganic coatings Hydrochloric acid (0.1 mol/l) or caustic
soda (0.1 mol/l)

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8. Maintenance
 Under normal conditions (e.g. clean medium, stable, non-extreme pH
values) cleaning is recommended every 14 days with monthly calibration.
 Electrodes are naturally consumed by loss of salt from the reference system,
etc. A drift in measured values after some time is therefore normal
measuring behavior.
 If the measured values drift, the electrode must be cleaned and calibrated!
 Cleaning and calibrating cycles can be adjusted depending on the
application and process parameters.

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9. Service life and warranty
 All pH and redox electrodes are wear parts. Their operational capability
("service life") depends on care and conditions of usage! Depending on the
application, the time until an electrode must be replaced could vary from a
few days to several years. Because of this, it is not possible to offer a
credible guaranty for a minimum service life.
 If the glass is broken, claims under the warranty are normally not honored.
 If you believe there may be a defect in material or manufacturing, please
contact your supplier.