Instruction manual

SM425 INSTRUCTION MANUAL 4.0 PIPING
Mount a check valve or stop valve (specified by Teledyne Monitor Labs) on the nipple (found on the open
market) at the calibration gas inlet of the detector as illustrated in Figure 4-8. (The check valve or the stop
valve may have been mounted on the detector when shipped.) Connect the flow setting unit and the
detector to a stainless steel pipe 6 mm (O.D.) ~ 4 mm or larger (I.D.) (or nominal size 1/4 inch).
Figure 4-8 Piping for the Calibration Gas Inlet
4.2.3 Piping for the Reference Gas
Reference gas piping is required between the air source (instrument air) and the flow setting unit. Also
between the flow setting unit and the detector.
Install an air-set (pressure regulator) in the piping between the air source and the flow setting unit. The
air-set (pressure regulator) should be close to the flow setting unit.
Use a 6 mm (O.D.) ~ 4 mm or larger (I.D.) (or nominal size 1/4 inch) stainless steel pipe between the flow
setting unit and the detector.
4.2.4 Piping to the High-temperature Probe Adapter
Refer to Section 1.18.4.
4.3 Piping for System 3
Piping in System 3 is illustrated in Figure 4-10. In System 3, calibration is automated. The piping is
basically the same as that of System 2. Refer to Section 1.19.
Adjust secondary pressure of both the air-set (pressure regulator) and the zero-gas reducing valve such
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, verify 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
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