13.1
Notes
13.2
General information
13.2.1
Calibration methods for Redox sensors
Zero-point calibration
Two-point Calibration
WARNING!
During the calibration, the relays and analog output signals assume the config-
ured states!
The calibration of Redox sensors is based on measurements in test solutions
with a defined Redox potential.
This calibration method is used to determine the Redox zero point.
A test solution with a defined Redox potential is needed as a reference.
"mV" must be set as the Redox unit in the configuration of the Redox measuring
input.
v Chapter 9.5.3 "pH/Redox/NH3 analysis inputs", Page 102
This calibration is used to establish an application-specific measurement char-
acteristic curve where Redox potentials are represented as a percentage of con-
centration values. The Redox potentials of 2 solutions are measured.
Concentration values in percent are then assigned to the measured values by
the user.
Two process-typical sample solutions are needed as calibration solutions as a
reference.
"Percent" must be set as the Redox unit in the configuration of the Redox mea-
suring input.
v Chapter 9.5.3 "pH/Redox/NH3 analysis inputs", Page 102
Example: In a detoxification plant, the toxicity of a liquid is to be measured on
the basis of the Redox potential. The calibration requires 2 solutions:
•
the concentration of the highly toxic solution is given as 80 % by the user, for
instance
•
the concentration of the detoxified solution is given as 10 % by the user, for
instance
Using the Redox potential, the toxicity can now be measured and displayed in
percent.
13 Calibrating Redox sensors
29