Teledyne 4020 - Hydrocarbon analyzer - Manual (Page 75)

Total Hydrocarbon Analyzer Operation
Teledyne Analytical Instruments 59
<▲▼> Use the <▲▼> keys to toggle between the Disabled,
User Select and Default (by Function) modes.
<Enter> Press when the appropriate function is displayed
on screen.
<Escape> Use Escape to move back to the Analyze Mode. Note that
the analyzer will now switch gas to the analyzer
depending on the choice shown on screen as detailed
below.
4.6.16.1 D ISABLED
When the valve selection mode “Disabled” is selected, the gas
connected to the sample port will be fed to the analyzer, i.e. the
“SAMPLE” port will always be open as the default stream fed to the
analyzer. During all modes of operation (Analyze, Span, or Zero), the
valve position will not be indicated on the screen as shown below.
or
and so forth for the zero mode.
4.6.16.2 U SER S ELECT
This option of valve selection allows the user to determine the
particular gas stream sent to the analyzer. Note that the valve selected
will be open during ALL modes of the instrument operation (Analyze,
Span and Zero).