36 Advanced Operation
3 Method Development
Times
Press [Time] and enter desired values for the timing
parameters used by the HS.
For the 111 vial model, the HS uses these parameters when
determining throughput. The most important value to a
sequence of samples is the GC Cycle time. If too short, samples
will be prepared before the GC or GC/MS is Ready.
Depending on the sequence action settings, this can cause
aborted samples or unexpected results. If the GC cycle time is
too long, throughput may be reduced, but at least the HS
maintains sample processing in accordance with the method.
In addition, there are other timings that the HS considers
when loading vials into the oven. Among these are:
• A 30 second wait time for all heated zones to stabilize at
temperature
• Fixed wait times for actions such as tray moves, carousel
moves, and lifter moves
• Fixed wait times for valve switches
• Other internal processing times
The HS considers all of these timings, as well as the
sequence of method setpoints, to determine the most
efficient schedule for processing the sample vials.
Table 3 Time parameters
Parameter Comments
GC cycle time The total time required for the GC (or GC/MS)
system to return to a ready state after a run. See
To Determine the GC Cycle Time in the
Operation guide.
Vial equib time The time the vial spends equilibrating at
temperature in the oven, including any shaking.
In general, start with a value of at least 15
minutes if an estimated time is unknown.
Pres equib time The time allotted for the vial to equilibrate at
pressure during vial pressurization. The default
inject time is 0.50 minutes.
Inject time The time allotted to sweep the sample from the
sample loop, through the transfer line, and into
the GC. The default inject time is 0.50 minutes.
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