Percent Paramagnetic Oxygen Analyzer Part I: Control Unit

Part I: 4-11

Teledyne Analytical Instruments
TRAK/HLD Auto-Cal
PSWD Logout More
- Use the Right or Left arrow keys and select More. Press Enter.
Version Self-Test
Show_Negative=NO
- 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 The

Zero

and

Span

Functions

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 that it will 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 longer to recover if the instrument is
used for trace or less than 1% full scale 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.
Shut off the gas pressure before connecting it to the analyzer, and
be sure to limit the pressure to 40 psig or less when turning it back on.
Readjust the gas pressure into the analyzer until the flowrate (as read on
the Analysis Unit SLPM flowmeter) settles between 0.5 and 2.4 SLPM
(approximately 1-5 scfh).