Hanna Instruments bl 7917 Manual Do Utilizador

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Reducing pretreatment: immerse the electrode for a few minutes in
HI 7091.
Oxidizing pretreatment: immerse the electrode for a few minutes in
HI 7092.
If the pretreatment is not performed, the electrode will take signifi-
cantly longer to respond.
As with pH electrodes, gel-filled redox electrodes are more suitable for
industrial applications due to lesser maintenance requirements. How-
ever, if working with refillable electrodes, the electrolyte level should
not fall more than 2½ cm (1") below the fill hole and topped up if
necessary. Use HI 7071 Refill Solution for single junction and HI 7082
for double junction electrodes.
In the event that measurements are performed with solutions contain-
ing sulfides or proteins, the cleaning of the diaphragm of the
reference electrode must be performed more often.
In order to have a correct functioning of the ORP electrode, immerse
it into HI 7020 and measure the response; the obtained value should
be within 200 and 275 mV.
After this functional test, it is suggested to wash the electrode
thoroughly with water and proceed to the oxidizing or reducing
pretreatment before taking measurements.
When not in use, the electrode tip should be kept moist and far from
any type of mechanical stress which might cause damage. This can be
achieved by installing the electrode in such a way that it is constantly
in a well filled with the sample (stream or tank). The protective cap
can also be filled with HI70300 Storage Solution if the electrode is
not being used at all.
Note: with industrial applications, it is always recommended to keep
at least one spare electrode handy. When anomalies are not
resolved with a simple maintenance, change the electrode to
see if the problem is alleviated.