Percent Paramagnetic Oxygen Analyzer Part I: Control Unit
Part I: 4-17Teledyne Analytical Instruments
latching or nonlatching, and either failsafe or nonfailsafe, or, they can be
defeated altogether. The setpoints for the alarms are also established using
this function.
Decide how your alarms should be configured. The choice will depend
upon your process. Consider the following four points:
1. Which if any of the alarms are to be high alarms and which if any
are to be low alarms?
Setting an alarm as HIGH triggers the alarm when the oxygen
concentration rises above the setpoint. Setting an alarm as LOW
triggers the alarm when the oxygen concentration falls below the
setpoint.
Decide whether you want the alarms to be set as:
• Both high (high and high-high) alarms, or
• One high and one low alarm, or
• Both low (low and low-low) alarms.
2. Are either or both of the alarms to be configured as failsafe?
In failsafe mode, the alarm relay de-energizes in an alarm
condition. For nonfailsafe operation, the relay is energized in an
alarm condition. You can set either or both of the concentration
alarms to operate in failsafe or nonfailsafe mode.
3. Are either of the alarms to be latching?
In latching mode, once the alarm or alarms trigger, they will
remain in the alarm mode even if process conditions revert back
to no-alarm conditions. This mode requires an alarm to be
recognized before it can be reset. In the nonlatching mode, the
alarm status will terminate when process conditions revert to no-
alarm conditions.
4. Are either of the alarms to be defeated?
The defeat alarm mode is incorporated into the alarm circuit so
that maintenance can be performed under conditions which
would normally activate the alarms.
The defeat function can also be used to reset a latched alarm.
(See procedures, below.)
If you are using password protection, you will need to enter your
password to access the alarm functions. Follow the instructions in Section
4.3.3 to enter your password. Once you have clearance to proceed, enter the
Alarm
function.
Press the
Alarm
button on the front panel to enter the
Alarm
function.
Make sure that AL1 is blinking.