Maintenance (regeneration)
SensoLyt
®
MPP-A Pt
12
ba75488e02
07/2011
5
Maintenance (regeneration)
First-time
activation during
installation and as
required
For first-time activation, use the activating powder provided with the SORT/
RH reagent set. Use a paper towel to gather a small amount of activating
powder. Using moderate pressure, press the activating powder against the
moist (but not dripping) platinum electrode from two opposite sides and turn
the electrode to and fro several times. Activation happens mainly due to
abrasion. Then remove the adherent remains of activating powder under
running water with a soft brush (e.g. toothbrush).
Activation during
very long set-up
times
When changing from oxidizing to reducing test solutions and vice versa this
can result in set-up times that can take significantly more than an hour. In this
case pretreatment (activation) of the platinum surface can shorten the set-up
time. The type of pretreatment (reducing or oxidizing) is based on the pH val-
ue and the ORP voltage (U
H
) of the test solution where the latter must be es-
timated for the first measurement.
The type of pretreatment can then be determined using the following diagram
where U
H
refers to the normal hydrogen electrode:
Oxidizing pretreat-
ment
Immerse the platinum electrode for two to three
days in a sulfuric clorina solution. Clorina powder
for producing the solution is included in the SORT/
RH reagent set.
Note: The junction must not be immersed in the clo-
rina solution (see figure below)!
Reducing pretreat-
ment
When the electrode is ready for the test immerse it
in the RH 28 ORP buffer solution and wait for a sta-
ble measured value.
1000
8
00
6
00
4
00
200
2
0
4
8
10
12
1
4
6
0
pH value
U
H
in mV
oxidizing pretreatment
reducing pretreatment
