Measuring The Redox Potential - JUMO 202710/20 Operating Manual

Measuring with temperature probe
5.3

Measuring the redox potential

Selecting the measurand
Definition
Measuring
Insert the pH combination electrode and the temperature probe into the
solution and gently stir until a stable measured value is achieved.
rH mV mV pH
H
ATC ok CAL AL Logg pH
If the device has been configured for a different measurand in a user-
defined operation, first select the measurand "mV" (see "Parameter
"InP": selection of a measurand", page 35).
The redox potential (or: ORP) indicates the extent to which the measured sam-
ple has an oxidizing or reducing effect in relation to the hydrogen standard
electrode.
This potential is often used in swimming pools as a measurand for the disin-
fecting effect of a chlorine. The redox value is also an important parameter for
aquarists as fish can only live within a particular redox range. The measured
value also plays an important role in drinking water treatment, water monitor-
ing, and in industry.
The measurement occurs with the commonly used silver/silver chloride com-
bination electrodes (reference system with 3 molar potassium chloride solu-
tion). The measured value can be taken directly ("mV" setting) or be automati-
cally converted with temperature compensation to the "hydrogen standard
electrode reference system" using the "mV
Calibration, such as with pH measurement, does not take place with redox
measuring. The suitability of combination electrodes can, however, be
checked at any time using redox test solutions.
Insert the redox combination electrode into the solution and gently stir.
rH mV mV pH
H
ATC ok CAL AL Logg pH
The measured pH value appears in the main display
and the measured temperature appears on the subsid-
iary display of the device.
H
The measured redox potential appears in the main dis-
play of the device.
If a temperature probe is connected, the measured
temperature also appears on the subsidiary display of
the device.
5 Measuring
" setting.
17