Micromeritics TriStar II 3020 Operator's Manual page 130

Analysis Conditions Files
Field or Button
Free Space button
(continued)
pº and T button
5-20
• Measure - select to measure the free space automatically over the
sample prior to data collection.
Lower Dewar for evacuation - lowers the Dewar during evacuation.
Enter the Evacuation time to allow for evacuation after the free space
measurement.
Outgas test - checks the system for sample outgassing after the free
space measurement. The outgas test seals the sample tube and monitors
the pressure. If the pressure rises more than 0.025 mmHg within the time
specified in the Outgas test duration field, outgassing is present. If
outgassing is found, the test repeats up to nine times with a 30-minute
evacuation time between each test. If the 10th test fails, the analysis does
not proceed and a cancellation message displays. Outgas testing slightly
increases analysis time, but it prevents continuation of analysis and
collection of erroneous data if outgassing is present.
• Enter - select to enter warm and cold free space.
Warm free space - sample tube gas capacity measured at room
temperature.
Cold free space - sample tube gas capacity measured with the Dewar
raised.
• Calculate - select to have the free space measurement calculated using
the sample and tube parameters.
Click to select options for obtaining the saturation pressure (Po) and
analysis bath temperature. Each selected option presents a different set of
parameters at the bottom of the screen.
Description (continued)
TriStar II 3020
302-42828-01 - Dec 2012