Teledyne GC-Pro/FID - Gas Chromatograph User Manual

Page 86

Operation GC-Pro

FID

Teledyne

Analytical

Instruments

is not related to relays that have both normally-open and
normally-closed terminals.

LATCHING: The latching property configures the alarm such that the
user must manually relieve the alarm condition even though the
concentration no longer violates the trip point of the alarm. So, if an
alarm is NON-LATCHING, and the analysis concentration temporarily
drifts above the trip point of a HIGH alarm, the alarm condition occurs
only during the time the concentration is above the trip point. If that
alarm were LATCHING, the alarm condition would persist (even though
the concentration is no longer above the trip point), until the user
released it.

RELEASING A LATCHED ALARM: When alarm conditions are
present, the relay associated with that alarm changes state. To reset from
an alarm condition, enter the Alarm 1 or Alarm 2 screen and disable the
alarm. Then re-enable the alarm. If the alarm condition still exists, the
alarm will again trigger.

TRIGGER POINT: This is the threshold at which an active alarm can
enter into alarm condition. If an alarm is HIGH, ACTIVE, and set at
20.00 ppb, then when the analysis concentration is at or above 20.00 ppb
an alarm condition is initiated or maintained.

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.