Teledyne GC-Pro/FID - Gas Chromatograph - Manual (Page 87)

GC-Pro FID Operation
Teledyne Analytical Instruments 73
Note: An alarm in 'alarm condition' is signaling that action must
be taken such as correcting the alarm or the analysis
concentration. If an active (not defeated) alarm has been
set to HIGH at 20.0 ppb, and the analysis concentration is
above that level, then the 'alarm condition' is occurring.
4.7.12.2 R ANGE
There are three settable analysis ranges on the GC-Pro FID
Analyzer. Both upper and lower bounds may be set. The value of each
limit on the currently selected range affects the corresponding upper and
lower value of the voltage and current of the analog outputs of the
analyzer as well as contact closures (if present) indicating which range is
current. The analog outputs from the 50–pin Equipment connector (see
Section 3.3.2.3 and Table 3-1) represent the proportion of the analysis
concentration to the currently selected range limit.
RANGE LIMITS: Ranges may be set for ppb, ppm, or percent
analysis however, range 3 can only be set at a value greater than range 2
and range 2 can only be set at a value greater than range 1.In addition,
the lower bound on each range must always be less than the upper
bound.
To set the ranges select “Range” from the SETTINGS screen. The
following screen will appear: