Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 494)

<Appendix E Computation Scheme>
App.E-21
IM 11B08A01-01E
(5) Upper and Lower Limit Checking
Upper and lower limit checking of 32 points can be set as to the following items.
If the conditions of the specifi ed upper and lower limit checking are not satisfi ed, an alarm is
generated.
For signal level processing, the base level value, signal level, and noise value should be checked
according to the processing details. In peak processing, the following four upper and lower limits
can be checked for each peak:
1. concentration value (including the base level value, signal level value, noise value, and
computed value)
2. retention time
3. variation coeffi cient
4. tailing coeffi cient
For deviation component computation and additional computation processing, the upper
and lower limits of computed values can be checked. Multiple items can be checked for each
processing as follows.
Stream number
Processing number
Item (concentration, retention time, etc.)
Upper limit
Lower limit
Alarm level
The alarm status is removed when:
• the value falls within the range between the limits; or,
• the operation mode is changed.
2nd Edition : May 11, 2012-00
App.E