User guide

Percent Paramagnetic Oxygen Analyzer Operation 4
4-13
Teledyne Analytical Instruments
displays the rate of change as Slope= a value in parts per million per second
(ppm/s).
#### % Zero
Slope=#### ppm/s
NOTE:It takes several seconds for the true Slope value to display.
Wait about 10 seconds. Then, wait until Slope is sufficiently
close to zero before using ENTER to finish zeroing.
Generally, you have a good zero when Slope is less than 0.05 ppm/s
for about 30 seconds. When Slope is close enough to zero, ENTER it. In a
few seconds, the screen will update.
Once zero settling completes, the information is stored in the
microprocessor, and the instrument automatically returns to the ANALYZE
screen.
4.10 The ALARMS Function
The Model 3020M is equipped with 2 fully adjustable concentration
alarms and a system failure alarm. Each alarm has a relay with a set of form
“C" contacts rated for 3 amperes resistive load at 250 V ac. See Figure in
Chapter 3, Installation and/or the Interconnection Diagram included at the
back of this manual for relay terminal connections.
The system failure alarm has a fixed configuration described in chapter
3 Installation.
The concentration alarms can be configured from the front panel as
either high or low alarms by the operator. The alarm modes can be set as
latching or non-latching, and either failsafe or non-failsafe, 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