Adsorptive Properties
In 21CFR11 environments, this section is applicable only to members of the Developer group; however, members of the Analyst group may find information in this section helpful. Parameter file information that is available to Analysts is created by a member in the Developer group using information in this section. |
File > Open > [.ADP File]
(or click Edit next to the Adsorptive selection on the Analysis Conditions tab when in Advanced option presentation)
Adsorptive properties provide the adsorptive (analysis gas) characteristics for the analysis.
Selections | Description | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Adsorbate molecular weight [text box] | The molecular mass is used for the weight % column of the isotherm tabular report and the pressure composition isotherm plot. | ||||||||||||
Adsorptive [text box] | Name of the adsorptive gas whose properties are being defined. | ||||||||||||
Density conversion factor [text box] | Factor determined by obtaining the ratio of the gas density (STP) to the liquid density.
where
|
||||||||||||
Dosing Method [group box] |
Normal. Dose from a pressurized tank of gas attached to a gas inlet port. From Psat tube. Select if the Psat tube is to be filled with condensed adsorptive and dosed from the Psat tube. |
||||||||||||
Ideal gas law with non-ideality correction [selection] |
Use if there is no compressibility table for the gas being used or to match existing data. This factor adjusts the ideal gas law for calculating the quantity of gas in the cold free space. Most gases are nearly ideal near room temperature and at pressures not much above atmospheric pressure, so the cold free space is where the correction is most important. If selected, enter the non-ideality factor field. | ||||||||||||
Maximum manifold pressure [text box] | The highest pressure to which the manifold will be dosed. To avoid damage to the analyzer, this number is limited to 925 mmHg. Low pressure sources will require lower numbers. For gases to be used for dosing after charging a tube from a gas inlet, enter the maximum pressure for dosing from the inlet, not from the tube of condensate. | ||||||||||||
Mnemonic [text box] | Enter the mnemonic name for the adsorptive. . | ||||||||||||
Molecular cross-sectional area [text box] | The area that a single adsorbed molecule occupies on the surface of the sample. It is used in surface area calculations. | ||||||||||||
Non-condensing adsorptive [check box] | Select if using a non-condensing analysis gas. When selected, the Density conversion factor field and the PSAT vs T button are disabled. | ||||||||||||
Non-ideality factor [text box] |
Compensates for the forces of attraction between molecules in a real gas. This value is used for a calculated free space. | ||||||||||||
Psat vs T [button] | Click to edit the Psat vs Temperature table. The table contains saturation pressures and their corresponding temperatures. To edit, click in a field and enter the value. | ||||||||||||
Therm. tran. hard-sphere diameter [text box] |
Estimate of the molecular size used in calculating the thermal transpiration correction. |
||||||||||||
|