Aging
SenTix
®
HW-T 900(-P)
8
ba77090e03
06/2021
4
Aging
pH electrodes are consumables. Every pH electrode undergoes a natural
aging process. With aging, the responding behavior becomes slower and
slower and the electrode slope and asymmetry change. Moreover, extreme
operating conditions can considerably shorten the lifetime of the electrode.
Extreme operating
conditions
NOTE
pH electrodes must not be operated under extreme operating condi-
tions. The electrode could be permanently damaged by this.
Examples for extreme operating conditions:
Strong acids or lyes, hydrofluoric acid, organic solvents, oils, fats, bro-
mides, sulfides, iodides, proteins
High temperatures
High changes in pH and temperature.
The warranty does not cover failure caused by measuring conditions and
mechanical damage.
5
Maintenance and cleaning
Refilling the
reference
electrolyte
During operation, a small amount of reference electrolyte leaks through the
junction from the electrode into the test sample. If the level of reference elec-
trolyte becomes too low with time, refill it through the refilling opening. Refill-
ing is very easy with the enclosed dropping bottle. Proceed as follows:
Cut off the tip of the dropping bottle at a right angle until the opening in the
tip can be seen
Open the refilling opening of the electrode
Press the tip of the dropping bottle into the refilling opening while turning
it slightly
Pump the reference electrolyte in the shaft using the dropping bottle
Pull the dropping bottle out of the refilling opening while turning it slightly
if necessary.
