EL3060 CONTINUOUS GAS ANALYZERS | OI/EL3060-EN REV. A 109
Shewhart control charts
Shewhart control charts are used to determine the combined precision and
drift of the AMS.
The differences d
t
between the measured values and the set points at the
zero point and the reference point are determined. These differences must
be less than or equal to the standard deviation s
AMS
multiplied by a factor of
2. If the difference for a measured value is greater, the measured value is
marked with the status "Out of Control".