Teledyne GC-Pro/TCD - Gas Chromatograph - Manual (Page 86)

Operation GC-Pro TCD
Teledyne Analytical Instruments 72
CAUTION: IT IS NOT GOOD PRACTICE TO SILENCE AN
EXISTING ALARM BY SETTING THE ALARM
ATTRIBUTE TO ‘DEFEAT”. THE ALARM WILL NOT
AUTOMATICALLY RETURN TO “ACTIVE” STATUS.
IT MUST BE RESET BY THE OPERATOR. IF IT IS
NOT RESET, YOUR PROCESS WILL BE RUNNING
WITHOUT THE SAFEGUARDS THIS INSTRUMENT IS
DESIGNED TO PROVIDE.
When finished configuring the alarms, touch the ENTER button at
the bottom right corner of the screen. A confirmation window will pop
up and by selecting “OK” the new alarm configuration will be the active
settings. Then, by touching the HOME icon, all alarm 1 inputs will be
saved permanently. Touching the CANCEL button will abort the inputs
and return the previously saved values.
The ALARM 2 screen is an identical screen for configuring
ALARM 2.
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.
4.5.12.2 R ANGE
There are three settable analysis ranges on the GC-Pro TCD
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.