Teledyne OT-3 - Manual (Page 35)

Trace Oxygen Analyzer Operation
Teledyne Analytical Instruments 27
When the alarms are set for delay and an alarm condition exists, the
display will alternate between the O
2
reading and the time in minutes
and seconds before the alarm will trigger. The alarm indicator on the
front panel will blink on and off. The delay time will continue to count
down until it reaches zero then the alarm relay will close. At this point
the display will stop blinking and the O
2
concentration will display
continuously. If a second alarm is reached after the delay time has
elapsed, it will trigger immediately without any delay. If the O
2
level
drops to below the alarm condition during the delay, the delay timer will
reset to the full delay.
If the alarm delay is set to 0 and an alarm condition exists, the
alarm indicator will blink and the alarm relay will close immediately.
When the O
2
level drops out of the alarm condition, the alarm relay will
drop out accordingly.
The alarm delay can be toggled on or off and the timing set through
the DELAY function. To set the alarm delay:
1. Press the UP and DOWN arrow keys simultaneously. The
display will indicate either PASS CODE or DELAY. If the
display indicates PASS CODE, then to set the delay, press both
arrow keys simultaneously again to toggle to DELAY.
2. While the display is blinking the word PASS DELAY, press the
UP arrow key to increase the delay. To decrease the delay, press
the DOWN arrow key. After three seconds the delay feature will
time-out and return to the analyze mode.
4.6 Keypad Lockout
The Model OT-3 has a keypad lockout feature which is designed to
prevent unauthorized changes to the analyzer. This feature is toggled on
or off via the PASS CODE function. To enable the keypad lockout:
1. Press the UP and DOWN arrow keys simultaneously. The
display will indicate either PASS CODE or DELAY. If the
display indicates DELAY, then to set the lockout feature, press
both arrow keys simultaneously again to toggle to PASS CODE.
2. While the display is blinking the word PASS CODE, press the
up or down arrow key to alter the code number. Any number
except 10 will lock the keypad.
3. After three seconds, the control unit will time-out and return
to analyze mode. With the keypad locked, pressing the keys