Teledyne 3020T - Manual (Page 51)

Trace Oxygen Analyzer Operation 4
4-15 Teledyne Analytical Instruments
to non-alarm conditions. This mode requires an alarm to be
recognized before it can be reset. In the non-latching mode, the
alarm status will terminate when process conditions revert to non-
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 4.4
to enter your password. Once you have clearance to proceed, ENTER the
ALARM function.
AL—1 AL—2
Choose Alarm
Use the DOWN/UP
control to blink your choice of alarm, AL-1 or
AL-2. Then ENTER to move to the next screen.
AL—1 1000 ppm HI
Dft—N Fs—N Ltch—N
Five parameters can be changed on this screen.
• Value of the alarm setpoint: AL–1 #### ppm (oxygen)
• Out-of-range direction: HI or LO
• Defeated? (Yes/No): Dft–Y/N
• Failsafe? (Yes/No): Fs–Y/N
• Latching? (Yes/No): Ltch–Y/N.
• To define the setpoint, use ENTER to blink AL–1 ####. Then
use the DOWN/UP control to change the number. Holding the
control on the DOWN or UP position, while the number changes,
speeds up the incrementing or decrementing. (Remember, the
setpoint units are always ppm O
2
.)
• To set the other parameters use ENTER to blink the desired
parameter. Then use DOWN/UP to change the parameter.
• Once the parameters for the alarm have been set, ENTER the
ALARM function again, and repeat this procedure for next alarm.
• To reset a latched alarm, go to
Dft– and then assert either DOWN
two times or UP two times. (Toggle it to
YYYYY and then back to N. N. N. N. N.)