CSC Scientific Blog

A blog about test equipment

CSC Scientific Blog

How Long Does a Water Activity Test Take?

Posted by Amanda Ranowsky on Jul 27, 2017 8:00:00 AM

The answer to the question, “How Long Does a Water Activity Test Take?” is, as with most testing questions, “it depends.” Some water activity meters promise a test completed in a very short time; some in as little as five minutes. This time is an arbitrary selection that may or may not produce a satisfactory result.

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Topics: Bound Moisture, Free Moisture, Moisture, Moisture Analysis, Water Activity, water activity measurement

What is Moisture Content?

Posted by Art Gatenby on May 29, 2012 3:24:00 PM

Last week, as I was reflecting on a recent moisture content problem, I recalled our series “Loss-on Drying and Other Moisture Mysteries.” In that series I examined moisture chemistry in products. However, I did little to define moisture content.

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Topics: Moisture, Karl Fischer, Karl Fischer Titration, Moisture Analysis, Moisture Testing, Bound Moisture, Free Moisture, Water Activity

Loss-on Drying and Other Moisture Mysteries - Part V: Drying

Posted by Art Gatenby on Jun 15, 2011 12:55:00 PM

Just over six months ago, I began this journey explaining the simplest approach to measuring or determining moisture: Loss-on Drying. Little did I know how involved and esoteric it would become.

This voyage has taken me down mysterious paths through spooky theories, back to age-old chemistry concepts and into the vagaries of thermodynamics related to evaporation, vapor pressure, bound water and water activity. I have come full-circle; back to explaining Loss-on Drying -- a form of drying that I had assumed would be the simplest of all.

I thought the first four topics [evaporation, vapor pressure, bound moisture, water activity] were tough, complex, confounding and less-than-obvious. Drying -- defined as “the mass-transfer process of removing water (or other solute) by evaporation from a solid, semi solid or liquid” -- seemed easy.

As is often the case, reality makes “easy” a non-operative word. Such has turned out to be so with respect to the issue of drying.

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Topics: Free Moisture, Moisture Sorption Isotherm, Moisture Analysis, Moisture Testing, Loss-On-Drying

Loss-On-Drying Moisture Analysis and Other Moisture Mysteries Part III: Free and Bound Water

Posted by Art Gatenby on Jan 25, 2011 4:18:00 PM

In my previous missive about Loss-On drying, we discussed Vapor Pressure -- because logically it was next. As we continue to explore moisture, we learn how vital vapor pressure is when regarding the quirky issues of free and bound water.

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Topics: Moisture, Loss-On-Drying, Moisture Analysis, Evaporation, Bound Moisture, Free Moisture, Moisture Testing

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