YOKOGAWA EXAxt ZR22G, User Manual, Page: 110 / 211

<7. Startup>
7-13
IM 11M12A01-02E
Enter
Mode: Manual

Points: Both

Zero gas conc: 1.00%

Span gas conc: 21.00%

Timing
Calibration setup
F7.16E.ai
Figure 7.27 Calibration Setup Display
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Calibration Setting Procedures
Select “Points” (calibration procedure) in the Calibration setup display to display the “Both, Span,
Zero” selection display. In this display, select “Both.”
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Calibration Gas Concentration Setting
(1) Zero gas concentration
If “Zero gas conc” is selected in the Calibration setup display, the numeric-data entry display
then appears.
Use this display to enter an oxygen concentration value for the zero gas calibration;
if the oxygen concentration is 0.98 vol%O
2
, enter 00098.
(2) Span gas concentration
With “Span gas conc” selected in the Calibration setup display, display the Numeric - data
Entry display and enter an oxygen concentration value for the span gas calibration; If
instrument air is used, enter 02100 for a 21 vol%O
2
value. When using the ZO21S Standard
Gas Unit (for use of the atmospheric air as a span gas), use a portable oxygen analyzer to
measure the actual oxygen concentration, and then enter it.
NOTE
• If instrument air is used for the span gas, dehumidify the air by cooling to a dew point of - 20
ºC and remove any oil mist or dust.
• If dehumidification is insufficient, or polluted air is used, a measurement accuracy may be
adversely affected.
7.12.2 Manual Calibration
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Preliminary
Before performing manual calibration, be sure that the ZA8F Flow Setting Unit zero gas flow
setting valve is fully closed. Open the zero gas cylinder pressure reducing valve so that the
secondary pressure equals sample gas plus approx. 50 kPa (or sample gas pressure plus
approx. 150 kPa when a check valve is used, maximum pressure rating is 300 kPa).
This applies even if you are using the ZR40H Automatic Calibration Unit.
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Calibration Procedures
This manual assumes that the instrument air is the same as the reference gas used for the span
gas. Follow the steps below to conduct manual calibration:
16th Edition : Mar. 19, 2020-00