Yokogawa Single Channel Oxygen Analyzer System ZR22/ZR402 - Manual (Page 72)

IM 11M12A01-03E 4-5
4. Piping
4.3 Piping for System 3
Piping in System 3 is illustrated in Figure 4.9. 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. 7.10.2), 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.
flow
meter flow
meter
REF
OUT
*2 *2
EV1 EV2
F2.6-3E.EPS
*2: Needle valve comes with flowmeter
It is recommended to use ZH21B dust protector to protect the probe output from dust
agitation (i.e., to prevent combustible materials from entering the probe cell) where
humidity measurements are made under dusty or combustible environment.
Instrument air
Calibration gas pressure regulator
Air Set
Needle
valve
Flowmeter
Reference gas
Calibration gas
Check valve ~
Zero gas cylinder
Model ZR40H Auto Calibration unit
Separate type Zirconia
High Temperature Humidity Analyzer
Model ZR22G Detecor Model ZR402G Converter
Calibration gas
unit case
F4.9E.EPS
EXA ZR402G
Conduit
100 to 240 V AC
Contact input
Analog output, contact output
Digital output (HART)
Signal
(6-core shield cable)
Heater (2-core shield cable)
Figure 4.9 Piping for System 3