Yokogawa Single Channel Oxygen Analyzer System ZR22/ZR402 - Manual (Page 71)

IM 11M13A01-02E 4-2
4.1 Piping for System 1
Piping in System 1 is illustrated in Figure 4.1.
~
ZA8F flow setting unit
EXA ZR402G
ZR22S Separate type Explosionproof ZR402G Converter
Reference gas
Calibration gas
Stop valve
or
Check valve
Needle
valve
flowmeter
Instrument air
Air Set
Pressure regulator Zero gas
cylinder
F1.1E.EPS
Span gas (*)
* Calibration gas unit same as for zero gas.
Zirconia Oxygen Analyzer, Detector
100 to
240 V AC
Non-hazardous area Hazardous area
Figure 4.1 Piping for System 1
System 1 illustrated in Figure 4.1 requires piping as follows:
• Connect a stop valve or check valve to the nipple at the reference gas inlet of the
detector.
• If a high-temperature detector is used and the sample gas is under negative pressure,
connect an auxiliary ejector to the sample gas exhaust hole of the high-temperature
probe adapter (see Section 4.1.5, Figure 4.3).
• If a high-temperature detector is used and the pressure of the measured gas is 0.5 kPa
or higher, it is recommended that a needle valve (throttle) be used in the sample gas
exhaust of the high-temperature probe adapter (see Section 4.1.5, Figure 4.4).
CAUTION
• This is for lowering the sample gas temperature below 700
Њ C. If the gas temperature is
high and the pressure is also significantly high, the sampled gas temperature may not
reduced below 700
Њ C when reaching the detector.
On the other hand, if the sample gas temperature is lowered too much, condensation
may be produced in the high-temperature probe adapter. During wintertime, it is
recommended that the probe adapter be protected with an insulating material to
prevent condensation (see Figure 4.5).
For the usage of the high-temperature probe adapter, refer to Section 3.2.2.
᭹ If the dust sticking to the interior of the high-temperature probe adapter is to be
eliminated by blow-back while using the high-temperature detector, the air feed for
blow-back should also be taken into consideration.
CAUTION
• The probe is easily clogged if too much dust is contained in the sample gas such as in
a utility boiler or concrete kiln. To get rid of the dust with compressed air, the piping
from the air source is connected only during cleaning. Blowback piping can be
installed for dust cleaning as illustrated in Section 4.2.