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Manual
MS-00809-0100-0470
NOTICE
If you intend to use locally generated instrument air, ensure that the pressure is sufficient
and use filters and dryers to ensure the actuation gas will meet the preceding
specifications in order to avoid excessive maintenance.
3.8.1
Helium actuation gas
When using the carrier gas as the actuation gas, tee the actuation gas supply connection
from the helium supply after the carrier drier.
3.8.2
Alternative actuation gas
If a gas other than the carrier gas is to be used as the actuation gas, connect the supply
directly to the actuation gas port on the gas chromatograph's (GC's) gas manifold.
Use nitrogen, dry air, or some other non-hazardous gas as the actuation gas.
WARNING
Do not use hydrogen as actuation gas.
3.9
Connect to the calibration gas
The gas chromatograph (GC) requires a high quality, certified calibration gas to ensure
accurate analysis. Although the Rosemount 470XA is typically set for an automatic daily
calibration run in custody transfer applications, you can use Rosemount MON2020 to
configure calibrations for any time frequency or set it to manual calibration only.
Prerequisites
The calibration gas must contain each component that you want to measure, ideally near
the center of the expected range of the sample gas component.. To ensure that all of
the components in the calibration gas remain in the gas phase and that the composition
remains consistent, install a calibration bottle heater blanket and use insulated or heat-
traced stainless steel tubing between the calibration gas and the GC.
Table 3-3
can be used with most common natural gas applications.
Table 3-3: Ideal calibration gas component concentrations
Component
Methane
Ethane
Propane
i-butane
n-butane
2.2 dimethyl butane
neo-pentane
iso-pentane
Rosemount 470XA
lists the recommended ideal component concentrations for a calibration gas that
Recommended concentration
89.57%
5.0%
1.0%
0.3%
0.3%
0.015%
0.1%
0.1%
Installation
June 2023
39
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