One quiet night, I was musing over moisture analysis and how easy it is to do using loss-on drying. Little did I know what was in store.
Topics: Evaporation, Moisture Analysis, Moisture Testing, Loss-On-Drying, Moisture, moisture balance, moisture content
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
Regularly I’m asked the question; “How accurate is this moisture balance?”
The questioner asks for the answer in terms of percent (%) moisture. When I answer “it depends”, I always get the unspoken response, “Why did I ask this stupid idiot?”
When you ask about the accuracy of something like weight or temperature the answers are straight forward and relate to the instruments' precision. For example 25 grams or 50 degrees plus or minus (+/-) 0.1 gram or 1/2 degree.
Percent is Relative
When you ask the question of how accurate is my percentage reading, the answer becomes complicated. It’s complicated because percentage (%) is a relative term. For example, the answer for the result of a Loss on Drying (LOD) moisture test, is based on the size of the sample you use.
Using the example of a LOD moisture test we can understand the concept. The result of this type of test is calculated by subtracting the weight of the sample at the end of the test from the weight of the sample at the beginning of the test. This difference is divided by the initial weight of the sample. This procedure produces a % moisture result.
In the following analysis, the implication s of sample size and instrument precision will be illustrated. This will be based on a sample that has 23.5% moisture and an electronic LOD moisture balance that has a sensitivity of 0.001 grams and repeatability of ± .005 grams.
Topics: Moisture Analysis, Moisture Testing, CSC Digital Moisture Balance, Loss-On-Drying, Moisture, moisture balance, instrument accuracy
Topics: Moisture Oven Test, Moisture Analysis, Moisture Testing, CSC Digital Moisture Balance, Loss-On-Drying, Moisture, fast moisture test, moisture balance, moisture content, moisture measurement
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.Read More
Topics: Bound Moisture, Free Moisture, Moisture Analysis, Water Activity, Moisture, water activity measurement
As people who measure moisture, we at CSC Scientific work to find the best technique.Read More
Topics: Moisture Analysis, Moisture Testing, Moisture, capacitance, fast moisture test
One quiet night, long ago I was musing over moisture analysis and how easy it is to do using Loss-on Drying (LOD). Little did I know what was in store.Read More
Topics: Bound Moisture, Moisture Analysis, Moisture Testing, Loss-On-Drying
Five years ago, we published an article on in-line vs. off-line moisture measurement. At that time we debated whether these measurement systems should be called on-line or in-line. We chose to use the term "on-line". Since then, however, the world of the internet became known as "online". So, to avoid confusion, we changed our view and now refer to direct measurement as "in-line" moisture measurement.Read More
Topics: Moisture Analysis, Moisture Testing, Loss-On-Drying, In-Line Moisture Measurement
Can you do a fast moisture test?
The answer is, “maybe”.
The direct methods of Loss on Drying and Karl Fischer have the benefit that between them they can get a good moisture content result on almost any product or material.
But these tests usually take several minutes.
When you need the moisture content in a truck load of grain while the load is being dumped, or when you need to check several hundred bags of coffee at an auction, or when you need to get a moisture gradient in a pile of corn, a faster test is crucial.
Can you do it?
The short answer is, “yes”. There are, however certain caveats to this answer.
Topics: "Ask Art", Moisture Analysis, Moisture Testing
Karl Fischer Titration and Loss-on Drying (LOD) are both methods for determining moisture content in a product.
That’s where the similarities end, though. In this article, I will explain the difference between Karl Fischer Titration and Loss-on Drying, and offer some suggestions to help you choose the right method for your application.
Topics: Moisture Analysis, Moisture Testing, Karl Fischer, Karl Fischer Titration, Loss-On-Drying