Yokogawa Single Channel Oxygen Analyzer System ZR22/ZR402 - Manual (Page 68)

IM 11M12A01-03E 4-1
4. Piping
4. Piping
This chapter describes piping procedures based on three typical system configurations
for EXAxt ZR Separate-type Zirconia High-temperature Humidity Analyzer.
• Ensure that each check valve, stop valve and joint used for piping do not allow
leakage. Especially, if there is any leakage of from the calibration gas pipes and
joints, it may cause clogging of the piping or incorrect calibration.
• Be sure to conduct leakage test after pipes piping.
• Basically, apply instrument air (dehumidified by cooling to the dew point –20
°
C or
lower, and removing any dust, oil mist and the like) for the reference gas piping.
• When the instrument uses natural convection for reference gas, ambient air near the
detector is used for reference gas; therefore the accuracy of analysis will be affected
by ambient temperature changes or the like. If more accurate analysis is necessary,
use instrument air (dehumidified by cooling to the dew point –20
°
C or lower, and
removing any dust, oil mist and the like) for reference gas.
Stable analyzing can be conducted when using instrument air.
4.1 Piping for System 1
The piping in System 1 is illustrated in Figure 4.1.
~
EXA ZR402G
Separate type Zirconia
High Temperature Humidity Analyzer
Model ZR22G Detector
Model ZR402G Converter
Stop valve 100 to 240 V AC
~
Model ZO21S Standard gas unit
Calibration gas
F4.1E.EPS
100/110/115
200/220/240 V AC
Contact input
Analog output, contact output
Digital output (HART)
Signal
(6-core shield cable)
Heater (2-core)
Figure 4.1 Piping in System 1
Piping in System 1 is as follows:
• Place a stop valve through the nipple at the calibration gas inlet of the detector. Then
mount a joint for a 6 mm (O.D.)
ϫ4 mm (I.D.) soft tube at the stop valve connection
hole of the inlet side (see Section 4.1.2). The tube is to be connected to this joint
only during calibration.
CAUTION
• The stop valve should be connected directly to the detector. If any piping is present
between the detector and the stop valve, water may condense in the pipe, which may
cause damage to the sensor by rapid cooling when the calibration gas is introduced.
The stop valve should be closed except while the calibration gas is being introduced.
Piping is required if the air around the detector is not clean.
• The reference gas should have an oxygen concentration identical to that of fresh air
(21%).