G 1501
Measurement Basics | 5
B-H86.0.12.DB2-2.1
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Solutions that contain high concentrations of silver ions
Substances that accumulate on the glass membrane or the diaphragm affect the
measurement and must be removed regularly. This can be achieved for example with
automatic cleaning systems.
5.1.5
Choosing a pH electrode
The GE 114 WD or GE 100 can be used for most applications. However, some areas
of application require special electrodes.
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GE 100 BNC is a universal electrode with two ceramic diaphragms and liquid elec-
trolyte.
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GE 101 BNC is preferably used for small sample amounts. It comprises a glass
electrode with two ceramic diaphragms and liquid electrolyte.
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GE 104 BNC is preferably used for measurements in low-ionic media, such as
rainwater, aquarium water and deionised water.
–
GE 114 WD is a universally applicable, durable and low-maintenance gel elec-
trode with Pellon diaphragm. It can be used for measurements in drinking water,
swimming pools, aquaria and slightly contaminated waste water.
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GE 117 BNC is a temperature-compensated gel electrode with two ceramic dia-
phragms and PH 13.5 cable screw coupling.
–
GE 120 BNC is an insertion electrode and is preferably used for measurements in
cheese, fruit and meat. For measurements in products containing proteins, the
electrode must be cleaned with a special cleaner. For this purpose, we recom-
mend the GRL 100 pepsin cleaning solution.
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GE 125 BNC is a waterproof, universally applicable, durable and low-maintenance
gel electrode with ceramic diaphragm. It can be immersed above the shaft for an
extended time.
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GE 151 BNC is a glass electrode and is preferably used in galvanic applications
for paints and lacquers.
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GE 173 BNC is an alkaline-resistant glass electrode with ground diaphragm and
gel electrolyte for chemical and waste water applications.
5.1.6
Service life
The service life of electrodes is normally at least 8 to 10 months. When cared for
properly, this can usually increase to more than 2 years. The actual life will vary de-
pending on the particular application.
5.1.7
Care and maintenance
NOTE
The glass tip of the electrode with the sensitive hydrated layer must be kept moist, e.g.
with 3 mol/l KCl solution in the storage cap. Accidental drying-out of the electrode can
be reversed under certain circumstances after storage for several hours in 3 mol/l KCl,
but this cannot be guaranteed.
NOTE
The GAK 1400 working and calibration set includes all necessary products for calibra-
tion, care and maintenance of the electrode. Normal cleaning takes place with the
