Emerson Rosemount 370XA System Reference Manual page 139

System Reference Manual
7P00370-H01
The following table lists some common problems along with their
solutions:
Problem
A single stream cannot be selected
for analysis but other streams can, or
one stream appears to be
contaminating other streams.
An analytical valve is not actuating
correctly.
The retention times for the
components have shifted later in the
analysis run, or valve switching
noise is excessive.
The un-normalized total is erratic
and fluctuates with changes in the
sample pressure.
The module is contaminated by a
large amount of liquids, or the
response of the detectors has
dramatically reduced.
The analyzer has been exposed to
significant contamination that
resulted in a reduction in the
separation of the components.
If the carrier gas pressure is not
being controlled or there is
excessive drift on the baseline, the
carrier gas pressure control valve
should be replaced.
6 - 2
370XA Gas Chromatograph
Solution
"Replace a stream selection solenoid" on
page 6-2
"Replace an analytical valve solenoid" on
page 6-5
"Overhaul an analytical valve" on page 6-
7
"Overhaul the sample shut-off valve" on
page 6-22
"Replace the detectors" on page 6-31
"Replace the chromatograph columns"
on page 6-37
It may be difficult to diagnose whether
the issue is with the pressure control
valve or the pressure sensor, so it is
recommended to replace both if there is
a problem with the carrier gas pressure
control.
APRIL 2014