216 AO2000 CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B
Automatic calibration
Definition
Automatic calibration means: Zero and span calibration run automatically
after starting.
Test gas supply
The test gas supply can be started automatically by means of the pneumatic
module’s solenoid valves or via external solenoid valves.
Depending on the gas supply circuit and the number of analyzer modules
installed there are several layout possibilities for the test gas supply (see
page 219).
Dew point
The dew point of the test gases must be approximately the same as the dew
point of the sample gas.
Analyzer modules with several detectors
In analyzer modules with several detectors (e.g. Uras26) all detectors are
calibrated simultaneously.
Starting the automatic calibration
Automatic calibration is started
• at time intervals determined by the internal clock
• by an external control signal or
• manually via the gas analyzer’s display and control unit.
Internal start
Automatic calibration is normally started cyclically on a time-controlled ba-
sis by the internal clock of the gas analyzer.
The cycle time is provided with a parameter with the calibration data (see
page 227).
External start
The "Start automatic calibration" control signal is needed for external start-
ing of automatic calibration:
Level Low 0 to 3 V → High 12 to 24 V edge. The Low → High transition
may also be generated by an external contact. After the transi-
tion the High level must be present for at least 1 s.
Input Digital input DI1 on Digital I/O module – "Status signals/ Exter-
nally controlled calibration" (see page 112) (standard function
block application)
To Next Page
Loading...
