Servomex 07931001B, Руководство оператора

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07931001B revision 6 © Servomex Group Limited. 2020
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The graph above illustrates a typical scenario where a measurement is initially
unstable
–
that is, the measured concentration or transmission is varying outside
limits that would be considered normal operation. The standard deviation falls over
time as the measurement stabilizes. It passes through the stability threshold level
and remains below the threshold until the stability time has elapsed. At that point the
measurement would be judged to be stable.
In-line Validation Process Flow
The In-line Validation process is structured as a sequential series of steps where the
operator is informed at each stage of any action that they need to take. The table
below shows the complete sequence of steps through the validation process. There
are two columns of screen displays in the table. The column on the left shows the
sequence that is followed if each step in the procedure was successful, i.e. the
process is stable, and the span concentration is within the permitted range. The third
column on the right shows steps occurring if the validation has failed. When such a
condition is detected the sequence will be terminated early.
For example, in the following scenarios the validation might be terminated earlier:
1. The analyzer is in warming mode when validation is selected.
2. The analyzer is in fault mode when validation is selected.
3. The process measurement is not sufficiently stable to allow a meaningful
validation result to be obtained.
Note that if a failure occurs while the validation cell contains span-gas, the operator
will be instructed to purge with zero-gas before the analyzer returns to normal
process measurements.