When Is Start Run; Control Table Parameters-Solvent Vent Operation - Agilent Technologies 6890 Series Operating Manual

Part 4. Using the Solvent Vent Mode

When is Start Run?

Both the inlet and oven temperature programs begin at Start Run. All times—
such as Purge time—are measured from Start Run. When does Start Run occur?
• If the sample is injected manually, Start Run occurs when the user presses
the Start Run key.
• If a single injection per run is made using an autosampler, Start Run occurs
when the syringe carrier moves down to make the injection.
• If multiple injections per run are made using an autosampler, Start Run
occurs when the syringe carrier moves down to make the first injection of
the set. There are no Start Run signals for the rest of the injections in the set.
These additional injections take time. The inlet and oven temperature
programs, mainly the Init time values, must be adjusted to allow for this.
So must the various time values that control the inlet operation. This is
discussed in more detail under Large Volume injections, later in this chapter.
Control table parameters—solvent vent operation
Mode: The current operating mode—solvent vent.
Temp Actual and setpoint initial inlet temperatures.
Init time The time, measured from Start Run, when the initial inlet
temperature hold ends. Usually greater than Vent end time.
Rate # Temperature program rate for inlet thermal ramps 1, 2, and 3.
Final temp # Final inlet temperature for ramps 1, 2, and 3.
Final time # Hold time at Final temp 1, 2, and 3. This time is a duration; it
is not measured from Start Run.
Pressure Actual and setpoint inlet pressure before and after the vent period.
It sets the starting point of column head pressure.
Vent pressure The inlet pressure during the vent period. By decreasing the
inlet pressure while venting, solvent elimination proceeds faster. Also, the
The Programmable Temperature Vaporization Inlet
When is Start Run?
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