Instruction manual

4.0 PIPING SM425 INSTRUCTION MANUAL
4.0 PIPING
This section describes piping procedures based on three typical system configurations for SM425
Separate-type Zirconia Oxygen Analyzer.
• Verify each check valve, stop valve, and joint used for piping does not leak. Calibration gas
leakage from pipes and joints may cause clogging of the pipes and inaccurate calibration.
• Test for leakage test after piping is installed.
• Verify instrument air is dehumidified to a dew point of -20°C or lower and free of particulate and
oil. Can also be used for the reference gas.
• Detectors using natural convection for the source of reference gas are affected by the ambient air
conditions near the detector. Process gas measurement accuracy can be influenced by changes
in the ambient air humidity, oxygen content, and pollutants. Consider using instrument air for
reference gas to improve measurement accuracy.
4.1 Piping for System 1
The piping in System 1 is illustrated in Figure 4-1.
Figure 4-1 Piping in System 1
Piping in System 1 is as follows:
• Mount a stop valve at the calibration gas inlet of the detector using a nipple. Mount a joint for a 6
mm (O.D.) X 4 mm (I.D.) soft tube on the stop valve (see Section 1.18.2). Connect the calibration
tube to this joint only during calibration.
42500001 REV A 67