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Alarms – Teledyne 3000PA - General purpose percent oxygen analyzer User Manual

Page 44

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4 Operation

Model 3000PA

4-12

Teledyne Analytical Instruments

of the displayed value of the oxygen concentration (in ppm) for three min-
utes. Then the instrument automatically returns to the analyze mode.

4.4.2.2

Manual Mode Spanning

Press

Span

to start the

Span

function. The screen that appears allows

you to select whether the span calibration is to be performed automatically or
manually.

Span: Settling:MAN
For Next

Use the

∆∇

keys to toggle between

AUTO

and

MAN

span settling.

Stop when

MAN

appears, blinking, on the display. Press

Enter

to move to

the next screen.

Span Val: 20.90
Span Mod #

Press

(

) to permit modification (

Mod #

) of span value.

Use the arrow keys to enter the oxygen concentration of the span gas

you are using (20.90 if you are using air). The < > arrows chose the digit,
and the

∆∇

arrows choose the value of the digit.

Press

Enter

to enter the span value into the system and begin the span

calibration.

Once the span has begun, the microprocessor samples the output at a

predetermined rate. It calculates the difference between successive samplings
and displays this difference as

Slope

on the screen. It takes several seconds

for the first

Slope

value to display.

Slope

indicates rate of change of the

Span

reading. It is a sensitive indicator of stability.

#### % Span
Slope=#### ppm/s

When the

Span

value displayed on the screen is sufficiently stable,

press

Enter

. (Generally, when the

Span

reading changes by 1 % or less of

the full scale of the range being calibrated for a period of five minutes it is
sufficiently stable.) Once

Enter

is pressed, the

Span

reading changes to the

correct value. The instrument then automatically enters the

Analyze

func-

tion.

4.5

The

Alarms

Function

The Model 3000PA is equipped with 2 fully adjustable concentration

alarms and a system failure alarm. Each alarm has a relay with a set of form