Micromeritics ASAP 2460, Operator'S Manual

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Analysis Conditions Files ASAP 2460 Operator’s Manual
3-22 246-42800-01 - Aug 2013
Dose Increments
option (continued)
•
Low Pressure incremental dose mode
- Choose this option when you
are performing an analysis of microporous materials. At low pressures
on Type 1 isotherms, the pressure points are very closely spaced, making
a useful pressure table difficult to define. Choosing this mode enables
you to measure equilibrium points at approximately equal intervals on
the quantity adsorbed axis. Each dose is fully equilibrated and recorded
as a data point.
In this mode, the sample is successively dosed with a specified amount
of gas until the first pressure point is reached. The first point is the
threshold value, triggering the transition from Incremental Dose Mode
to Pressure Table Mode. When the first pressure table value is reached,
Incremental Dose Mode is disabled, and points are recorded in
accordance with the specified pressure table. Because the data points
recorded during Incremental Dose Mode may define most of the
analysis, one point on the pressure table can be sufficient and serve as
the end point for the analysis.
This field is disabled if
First Pressure Fixed Dose Mode
is selected.
•
Dose amount
- Enter the amount of gas to be added to the sample for
each data point until the first point on the pressure table is reached.
Enabled when
Low pressure incremental dose mode
is selected.
•
Equilibration delay
- Enabled when
Low pressure incremental dose
mode
is selected.
Minimum:
Prevents premature equilibration caused by reduced
percentage sensitivity to pressure changes at the lowest pressures
.
Maximum:
Prevents the effects of long term temperature or pressure
drift, which may cause the instrument to wait an excessive length of time
for equilibration.
Field or Button Description (continued)