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8019897/V2-0/2017-12| SICK
O P E R A T I N G I N S T R U C T I O N S | PowerCEMS100
Subject to change without notice
ADJUSTING
8
8
Adjusting
8.1
Adjustment purpose
It is unavoidable that some of the properties of Analyzer modules will change during the
operating time. This changes measurement results even when external conditions remain
identical.
This gradual change in measured results is known as drift. Zero point drift and reference
point drift exist. These drifts are measured during adjustment and the relation between real
concentration and measured value (characteristic curve) is corrected accordingly (see
The linearity of the characteristic curve (proportional relation between real value and mea-
sured value) can also be corrected afterwards .
Fig. 8: Adjustment functions (schematic)
8.2
Principle adjustment procedure
▸
A test gas is fed in.
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A measured value (actual value) is determined with this test gas.
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This actual value is then compared against the programmed setpoint value.
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The internal adjustment parameters are then corrected mathematically so that the
actual value then corresponds to the setpoint value.
To attain complete adjustment, this procedure must be performed twice for each measur-
ing component – once for the zero point and once for the reference point. Relevant
sequence control programs control these procedures.
When is adjustment
necessary
The PowerCEMS100 analysis system and/or the analyzers have to be adjusted:
●
approx. 12 - 24 h after commissioning
●
at regular intervals during operation
●
For emission measurement required by law according to the Certification or legal specifi-
cations (according to TÜV performance test report).
Zero point adjustment Reference point adjustment Linearity adjustment
Note
Choose larger adjustment intervals when possible (e.g. 3 or 6 months) when
permitted by the application or when expressly allowed (see TÜV performance
test report).
Note
▸
The specific adjustment cycles depend on the application and are not the
responsibility of SICK AG.