The Zero And Span Functions - Teledyne 3020T Operating Instructions Manual

Operation
During preamp testing there is a countdown in the lower right
corner of the screen. When the testing is complete, the results are
displayed.
The module is functioning properly if it is followed by OK. A
number indicates a problem in a specific area of the instrument. Refer to
Chapter 5 Maintenance for number-code information. The results screen
alternates for a time with:
Then the analyzer returns to the ANALYZE screen.

4.8 The Zero and Span Functions

Note: 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 limits.
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 according to the instructions 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.
Teledyne Analytical Instruments
Power: OK Analog: OK
Preamp: 3
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Model 3020T
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