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Teledyne 3020M - Explosion proof paramagnetic oxygen analyzer User Manual

Page 49

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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