Maintenance And Storage Of Ph / Redox Electrodes; Dissolved Oxygen; Preparation Of The Oxygen Electrode (First Filling And Top-Up) - Tintometer Lovibond SD 335 Multi Manual De Instrucciones

5 .6 Maintenance and storage of pH / redox electrodes

Gel electrodes that cannot be topped up are wear parts, and their service life and measuring
accuracy depend significantly on their use, storage and care. Incorrect storage, as well as
particular samples, such as those with aggressive chemicals, high potential for contamination
and high temperature, can shorten the life expectancy of the electrode to a few months or
even weeks. Samples with very poor conductivity – that is, a very low salt content – prolong
the electrode's response time. Electrodes undergo a natural ageing effect, which leads to
a shift in the electrode's offset point and slope. To slow down the ageing process and to
preserve the associated performance and accuracy, please observe the following:
!
Never store pH and redox electrodes in distilled water or solutions with
a pH > 8! This would result in a drastic reduction in their service life.
To slow down the ageing process of the pH and ORP electrodes, we recommend
storing them in a suitable storage solution when not in use. Solutions with 3 M
KCl are particularly suitable for this purpose. Before immersing the electrode in the
storage solution, we recommend rinsing it carefully with distilled water.

6 Dissolved oxygen

6 .1 Preparation of the oxygen electrode (first filling and top-up)

Storage
solution
Unscrew the sealing screw
from the refill opening
Fill the sensor completely
with KOH via the refill
opening
52
The sensor is supplied dry and must be filled before first use!
Take care when working with KOH. The electrolyte is cor-
rosive. Avoid contact with the skin and protect the eyes!
*Suitable gloves according to DIN EN 420, for example made of natural latex, natural
rubber, butyl rubber, nitrile rubber, polychloroprene, or fluorinated rubber.
Remove the membrane
head by twisting it
Remove any air bubbles by
tilting gently
Fill the membrane head to
3/4 full with KOH
Close the refill opening
with the sealing screw
Screw the membrane head
firmly in place
Before first use: store the
sensor for 2 hours in the
storage flask (filled with
distilled water)
SD_335_1 10/2020