Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 17)

<1. Overview>
1-2
IM 11M12A01-04E
CAUTION
• As this system uses ambient air for the reference gas, measuring accuracy will be affected by
the installation location.
• A stop valve should be connected to the calibration gas inlet of the equipment. The valve should
be fully closed unless calibration is in progress.
1.1.2 System 2
This system is for monitoring and controlling oxygen concentration in the combustion gases of a
large-size boiler or heating furnace. Instrument air (clean and dry air of oxygen concentration 21%)
is used as the reference gas and the span gas for calibration. Zero gas is fed from a cylinder during
calibration. The gas flow is controlled by the ZA8F flow setting unit (for manual valve operation).
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ZR202G Integrated type Zirconia Oxygen Analyzer
F1.2E.ai
ZA8F flow setting unit
Reference gas
Calibration gas
Needle
valve
Flowmeter
Instrument air
Air Set
Calibration
gas pressure
regulator
Zero gas cylinder
Calibration gas unit case
Stop valve
or
Check valve
Span gas(Same as Zero gas calibration)
100 to 240 V AC
Contact input
Analog output, contact output
Digital output (HART)
Figure 1.2 Example of System 2