The Zero And Span Functions - Teledyne 3000TB Instruction Manual

Trace Oxygen Analyzer
To show negative oxygen readings on the display:
- Press the System key
- Use the Right or Left arrow keys and select More. Press Enter.
- Use the Right or Left arrow keys and select
"Show_Negative=NO".
- Use the Up or Down key to toggle from NO to YES.
- Press the Escape key twice to return to the analyze mode.
This preference is stored in non-volatile memory, so this configuration
is remembered after a power shutdown. If the instrument is cold started, it
will go back to default (not showingg negative oxygen readings).
4.4
Zeroing is not required in order to achieve the published
accuracy specification of this unit.
Zeroing will eliminate offset error contributed by sensor,
electronics, and internal and external sampling system and
improve performance beyond published specification lim-
its.
The analyzer is calibrated using zero and span gases.
Any suitable oxygen-free gas can be used for zero gas as long as it is
known to be oxygen free and does not react adversely with the sample
system.
Although the instrument can be spanned using air, a span gas with a
known oxygen concentration in the range of 70–90% of full scale of the
range of interest is recommended. Since the oxygen concentration in air is
20.9% (209,000 ppm), the cell can take a long time to recover if the
instrument is used for trace oxygen analysis immediately following
calibration in air.
Connect the calibration gases to the analyzer according to the instruc-
tions given in Section 3.4.1, Gas Connections, observing all the prescribed
precautions.
TRAK/HLD Auto-Cal
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Version Self-Test
Show_Negative=NO

The Zero and Span Functions

Teledyne Analytical Instruments
Operation 4
4-11