JUMO AQUIS touch P 202580, Operating Manual

Page: 169 / 322

169
12 Calibration
in general
12.1 Notes
12.2 General information
The actual electrical characteristics of analysis sensors always deviate some-
what from the nominal specifications. The reasons for this include:
•
Like every measuring instrument, analysis sensors always have a certain
measurement uncertainty that results from manufacturing tolerances.
• During use, analysis sensors are exposed to chemical processes. Deposits
and wear phenomena caused by these processes result in changes of the
electrical characteristics of sensors.
To optimize the accuracy of measurements, analysis sensors must be calibrat-
ed. Calibrations are required:
•
during installation or when changing a sensor
• regularly at time intervals that must be specified by the user
• if implausible measuring values are displayed
• if process conditions change, e. g. as the result of equipment modification
Calibration timers can be configured to provide a regular reminder of when cal-
ibrations are due.
v
Chapter 10.10 "Calibration timers", Page 139
Each successfully completed calibration is recorded in the calibration
logbook.
v
Chapter 12.3 "Calibration logbook", Page 171
12.2.1 General procedure for calibration
True calibration (calibrating with routines)
After opening one of the calibration routines in the device, the user is guided
through a process with measurements and entries. In the course of this process,
the calibration values are determined and saved automatically.
Suitable calibration routines are available for every type of analysis sensor. The
individual calibration routines for the various sensor types are described in sep-
arate chapters.
v
Chapter 13 "Calibrating a pH measuring chain", Page 175 to Chapter 17 "Cal-
ibrating Ci conductivity sensors", Page 197
Execution of calibration routines requires that the following prerequisites be met:
WARNING!
During the calibration, the relays and analog output signals assume the config-
ured states!