Micromeritics ASAP 2460 Operator's Manual page 305

ASAP 2460 Operator's Manual
4041- Cheng/Yang correction is inappropriate for some P/Po.
Cause:
Action:
4042- 0.0 cannot be a starting or ending pressure for a geometric progression from
low pressure.
Cause:
Action:
4043- 1.0 cannot be a starting or ending pressure for a geometric progression toward
saturation.
Cause:
Action:
4044- Points in the Langmuir report pressure table lie outside the collected data.
Cause:
Action:
246-42800-01 - Dec 2013
The Cheng/Yang correction is usually inappropriate for any P/Po above
the isotherm knee. In some instances, the computed pore sizes may
decrease above the knee. While it is possible to include these relative
pressures (usually above 0.1 P/Po) in the analysis, the computed pore
sizes for these pressures are usually meaningless.
Change the data points selected for the Horvath-Kawazoe report to
include only relative pressures at or below the knee of the isotherm, or
change the Horvath-Kawazoe report options so that the Cheng/Yang
correction is not applied.
You selected to generate a pressure table from a geometrically pro-
gressing range.
Change the 0.0 entered value.
You selected to generate a pressure table from a geometrically pro-
gressing range.
Change the 1.0 entered value.
Calculation assignments are not being used and more than one of the
report pressure table points is above the range of the collected data, and
more than one is below.
Change the report pressure table to be more consistent with the col-
lected data.
Appendix B
B-25