Application Note

Calculate High-Pressure Isosteric Heats Of Adsorption From Isotherms Measured At Differing Temperatures

Source: Micromeritics Instrument Corporation

An update in version 3.0 of Micromeritics’ MicroActive software allows for pasting HPVA II data into MicroActive sample files. This feature is extremely useful for fitting data to various isotherm models and for calculating isosteric heats of adsorption from isotherms measured at differing temperatures. The following instructions explain how to paste HPVA II data into MicroActive and use the sample files to calculate heats of adsorption:

Version 22.0.9 of the HPVA II Excel macro automatically prints columns of data with appropriate headers for pasting into MicroActive. Activate this function by selecting “Edit” from the “HPVA Options” menu. Check the “Print MicroActive Data” box and click OK.

When an isotherm report is generated the MicroActive data is located at the bottom of the spreadsheet. Copy the two columns of data, including the two column headers labeled "Absolute Pressure (mbar)" and either "Quantity Adsorbed (cm3/g STP)" or "Quantity Adsorbed (mmol/g)"

Micromeritics Instrument Corporation