At one end of the spectrum of the moisture world is the classic Speedy Moisture Tester where you use the reaction of water with calcium carbide to cause a mini explosion resulting in a moisture measurement reading. This method is used frequently for soils, concrete, and other like materials.
Topics: Moisture Sorption Isotherm, Moisture Analysis, Water Activity, Karl Fischer, Loss-On-Drying
Moisture Content and Water Activity - What Are They?
Posted by Art Gatenby on Nov 11, 2021 5:04:31 PM
Many accessing our web site ask questions such as:
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“How does water content affect water activity?”
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"How is water activity different from water content?”
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”Can I convert from moisture to water activity?”
I previously commented on water activity and now hope to clarify the differences between water activity and moisture content. Given that both of these measurements deal with water connected to a material, we must first understand of water content in a product.
Topics: Moisture Sorption Isotherm, Moisture Analysis, Water Activity, moisture content, moisture measurement, water activity measurement, water content measurement
Loss-On-Drying Moisture Analysis and Other Moisture Mysteries Part IV: Water Activity
Posted by Art Gatenby on Nov 11, 2021 3:27:32 PM
Loss-On-Drying moisture analysis seemed like a simple process until, in a state of naïve bliss, I promised to look at evaporation, vapor pressure and bound water. While I was otherwise occupied with hese realities, I offered to enter the world of witchcraft and folklore; water activity.
Topics: Bound Moisture, Moisture Sorption Isotherm, Moisture Analysis, Water Activity, Loss-On-Drying
Water Activity Measurement and the Illusion of Quick and Accurate
Posted by Art Gatenby on Aug 17, 2021 2:00:38 PM
Water Activity
Water activity is the water in a material available to support the growth of microorganisms. Consequently, the measurement of water activity is important in areas such as food processing, pharmaceutical production, products affected by mold, and a host of products that change characteristics when exposed to moisture.
Read MoreTopics: Water Activity, stop mold, chilled mirror, aw
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.
Topics: Bound Moisture, Free Moisture, Moisture Analysis, Water Activity, Moisture Testing, Karl Fischer, Karl Fischer Titration, Moisture
Moisture Content - Water Activity – Are They the Same Thing?
Posted by Art Gatenby on Mar 6, 2012 4:19:00 PM
The other day, I woke up with a lingering quandary: Are the concepts of
Moisture Content and Water Activity the same thing?
As usual, I’ve decided to take on the task of clarifying the difference. I hope I pull it off.
From the perspective of someone who supplies instruments that measure moisture content, water activity has not been a primary consideration. However, I believe that comparison and contrast of these important concepts will be useful.
Topics: Moisture Sorption Isotherm, Infrared Moisture, Moisture Analysis, Water Activity, Moisture Testing, bound water