Trace Oxygen Analyzer Operation 4
4-15
Teledyne Analytical Instruments
sponds, within tolerance, to the value of the span gas concentration. 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
<ENT> For Next
Use the Δ∇ 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.
Press Enter to move to the next screen.
Calib. Holding time
Cal hold: 5 min
This menue allows the operator to set the time the analyzer should be
held in the AUTO span mode. It does not have any effect in the MANual
mode. Just press Enter key to continue.
Span Val: 000008.00
<ENT>Span <UP>Mod #
Press Δ (<UP>) to permit modification (Mod #) of span value.
Use the arrow keys to enter the oxygen concentration of the span gas
you are using (209000.00 if you are using air). The < > arrows choose the
digit, and the Δ∇ 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 a Slope on the screen. It takes several seconds
for the first Slope value to display. Slope indicates the 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 ten minutes it is