Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 68)

<4. Pipomg>
4-8
IM 11M12A01-02E 8th Edition : Jan.13,2012-00
4.3 Piping for System 3
Piping in System 3 is illustrated in Figure 4.10. In System 3, calibration is automated;
however, the piping is basically the same as that of System 2. Refer to Section 4.2.
Adjust secondary pressure of both the air set and the zero gas reducing valve so that these
two pressures are approximately the same. The flow rate of zero and span gases (normally
instrument air) are set by a single needle valve.
After installation and wiring, check the calibration contact output (see Sec. 7.11.2), and adjust
zero gas reducing valve and calibration gas needle valve so that zero gas flow is within the
permitted range. Next check span gas calibration contact output and adjust air set so that span
gas flow is within the permitted range.
CHECK
OUT
ZERO GAS IN
AIR IN
Instrument air Approx.
1.5 l/min.
Flowmeter Flowmeter
REF
OUT
*2 *2
EV1 EV2
Solenoid valve
EV1, EV2
F2-6-3E.ai
*2: Needle valve is supplied as accessory with flowmeter
Figure 4.9 Piping inside in System 3
When blow back function is used by contact input to the ZR402G converter, install blow back
piping as illustrated in Section 4.3.1.
NOTE
Blow back function means the function to get rid of dust inside a probe in a high temperature
probe adapter by using compressed air, when a high temperature detector is used.
Instrument air
Pressure
reducing
valve
Air Set
Needle
valve
Flowmeter
Reference gas
Calibration gas
Check valve
~
Zero gas cylinder
ZR40H
Automatic Calibration Unit
ZR22G Separate type
Zirconia Oxygen Analyzer, Detector
ZR402G Converter
Calibration gas
unit case F4-9E.ai
EXA ZR402G
100 to 240 V AC
Contact input
Analog output, contact output
Digital output (HART)
Signal
(6-core shield cable)
Heater (2-core cable)
Figure 4.10 Piping for System 3