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Teledyne 3020M - Explosion proof paramagnetic oxygen analyzer User Manual

Page 48

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4 Operation

Model 3020M

4-12

Teledyne Analytical Instruments

If you have trouble zeroing, you may need to skip to section 4.8.1.3

Cell Failure.

Auto Mode Zeroing

Select

ZERO

to enter the

ZERO

function. The

ZERO

screen allows

you to select whether the zero calibration is to be performed automatically or
manually. Use the DOWN/UP control to toggle between

AUTO

and

MAN

zero settling. Stop when

AUTO

appears on the display.

Zero: Settling: AUTO
To Begin

ENTER to begin zeroing.

#### % Zero
Slope=#### ppm/s

The beginning zero level is shown in the upper left corner of the dis-

play. As the zero reading settles, the screen displays and updates information
on

Slope

(unless the Slope starts within the acceptable zero range and does

not need to settle further).

Then, and whenever Slope is less than 0.08 for at least 3 minutes,

instead of Slope you will see a countdown, such as

1 Left

,

0 Left

. These are

steps in the zeroing process that the system must complete, AFTER settling,
before it can go back to ANALYZE.

#### % Zero
1 Left=### ppm/s

The zeroing process will automatically conclude when the output is

within the acceptable range for a good zero. Then the analyzer automatically
returns to the ANALYZE screen.

Manual Mode Zeroing

ENTER the

ZERO

function. The screen that appears allows you to

select between automatic or manual zero calibration. Use DOWN/UP to
toggle between

AUTO

and

MAN

zero settling. Stop when

MAN

appears on

the display.

Zero: Settling: Man
To Begin

ENTER to begin the zero calibration. After a few seconds the first of

five zeroing screens appears. The number in the upper left hand corner is the
first-stage zero offset. The microprocessor samples the output at a predeter-
mined rate. It calculates the differences between successive samplings and