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Teledyne 3020M - Explosion proof paramagnetic oxygen analyzer User Manual

Page 47

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Percent Paramagnetic Oxygen Analyzer

Operation 4

4-11

Teledyne Analytical Instruments

4.8.1.2

Manual Mode Spanning

ENTER

SPAN

from the MAIN MENU 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 DOWN/UP to toggle between

AUTO

and

MAN

span settling. Stop

when

MAN

appears on the display. Use ENTER to move to the next screen.

Span Val: 20.90
Span Mod #

Use UP to permit modification (

Mod #

) of span value.

Use ESCAPE/ENTER to choose the digit, and use DOWN/UP to

choose the value of the digit.

When you have finished typing in the concentration of the span gas you

are using, repeatedly select ENTER until the rightmost digit is reached, then, the
next ENTER will exit the Span Val field. One more ENTER will enter the new
span value, bring up the next screen, and start 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,

ENTER it. (Generally, when the

Span

reading changes by 1 % or less of the

full scale of the range being calibrated for a period of ten minutes it is suffi-
ciently stable.) Once you ENTER it, the

Span

reading changes to the correct

value. The instrument then automatically enters the ANALYZE function.

4.9

Zero Cal

The

ZERO

function on the MAIN MENU is used to enter the zero

calibration function. Zero calibration can be performed in either the auto-
matic or manual mode. In the automatic mode, an internal algorithm com-
pares consecutive readings from the sensor to determine when the output is
within the acceptable range for zero. In the manual mode, the operator
determines when the reading is within the acceptable range for zero.

Make sure the zero gas is connected to the instrument.