Hach-Lange 5338 - Manual (Page 4)

4
pH electrode 53 38
Introduction
The 53 38 is a pH electrode for general
use. Low maintenance electrode, as it
does not require monitoring of electro-
lyte level.
SAFETY NOTE
Before use with hazardous substanc-
es, find out about the relevant haz-
ards, protective measures, and what
to do in an emergency.
Electrode preparation
• Remove the storage protector
.
• Verify that there are not air bubbles
inside the membrane . They can be
removed by shaking the electrode as a
clinical thermometer.
Installation
In immersion, insertion, flotation housings,
etc. with PG 13,5 thread.
See Housing instruction manual.
In some cases the electrode is installed,
with the help of sockets and adapters,
directly onto pipes.
Calibration
See pH-meter instruction manual.
Measurements. Recommendations
See pH-meter instruction manual.
Ensure that the electrode’s specifications
are adapted to the process.
Sample must cover the diaphragm
.
Maintenance
• Deposits forming on the electrodes,
caused by continual exposure of the sen-
sors to a dirty or contaminated medium, is
one of the most frequent causes of prob-
lems when measuring pH. When possible
it’s recommended to use a housing with
automatic sensor cleaning system.
• When an electrode gets contaminated,
the simple rinsing with distilled water is
not suffi cient. The most suitable clean-
ing solution is one which acts in a more
selective way over the contamination
(look for regeneration solutions).
• Re-hydration. A “dry” electrode re-
covers by immersing it in diluted HCl
solution for several hours. It is recom-
mended to read the information sup-
plied with the electrode’s regenerating
solutions.
Troubleshooting
... the meter always shows the same pH
value.
Short circuit in the electrode or cable.
Replace the electrode.
... shifting of pH values.
Reference system contamination.
Replace the electrode.
... unstable reading.
Diaphragm blockage.
Clean, regenerate, replace the elec-
trode.
... impossible to perform calibration.
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