Intrinsic Viscosity Models

ASTRA now supports converting specific viscosity (measured using the ViscoStar instrument) to intrinsic viscosity using the three standard formalisms, Huggins, Kraemer, and Solomon-Gatesman.

The only user interface change is in the Define Peaks view, where new viscometry data fields have been added. A new section entitled "Eta Analysis" contains the desired viscometry model (Huggins, Kramer, or Solomon-Gatesman) as well as the Huggins and Kraemer constants to use in the calculation.

ASTRA has historically used the Huggins relation with a "Huggins Constant" of zero, so existing ASTRA data files default to this setting.

Running the analysis with the defaults (Huggins, K’=0.0) we get the following (the results ASTRA has always produced for this data):

If we go to the "Define Peaks" view and switch to the Solomon-Gatesman formalism (which does not require any coefficients), we can see that the results are slightly different.

First, change the viscosity model to Solomon-Gatesman:

Then view the report and see the change in the results:

Finally, we can try the Kraemer model using a completely made-up Kramer Constant (K’) of 0.25:

This yields a final set of values for the data:

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