Micromeritics GEMINI VII KEYPAD Operator's Manual page 67

Analysis Condition Prompts (continued)
Field or Button
Free space
Previous
Measure
Calculate
Gemini VII Keypad Operator Manual
239-42801-01 (Rev E) — July 2021
Description
Typically, materials having surface areas greater than 25-50 m
can be analyzed accurately without free-space measurement.
Select the method for handling free-space measurement.
Choices: None, Previous, Measure, Calculate
Uses the free spaced applied to the previous sample.
Provides a more accurate, but slower, analysis. If analyzing a series
of samples with similar volumes, measure the first sample, then
select Previous for the remaining samples.
Provides high accuracy without the additional time required for free-
space measurement. This method also includes a balance volume
correction and a nonideality correction.
The free-space correction is calculated by dividing the sample mass
by the sample density to get the sample volume. When Calculate is
selected, the following prompt is displayed for entry of the sample
density. Enter the density of the sample to be analyzed.
(Pycnometers are available from Micromeritics for automatic density
measurement.)
Range: 0.000 to 99.999 g/cm
An approximate value is adequate to provide an accurate free-space
correction.
Analysis Conditions
3
2
/g
3 - 15