We get the same two questions almost every week about the CSC Bostwick Consistometer:
1) What angle do I use to set it up?
2) How do I level the Consistometer?
The principle of the CSC Bostwick Consistometer is based on the slump cone. In this procedure, a cone is filled with the material to be tested. It is then set on a level surface with the open area facing downward. The cone is pulled away and after a fixed time, the amount that the material slumped is measured. The thicker the material, the less slumping occurs.
The answer, like most answers in the crazy measurement world, is, “it depends”. To find out what it depends on, we'll start with defining viscosity.
As usual when we pose a question, like:
Should you use Coulometric or Volumetric Karl Fischer to measure moisture in your product?
We often get a the reaction, “So Who Cares?” We'll try to answer both questions.
Coulometric Karl Fischer,
Volumetric Karl Fischer,
Karl Fischer Titration
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.
Karl Fischer Titration,
The CSC Sieve Analyzer
The CSC Sieve Analyzer was designed to deliver a record of a sieve test results, eliminate operator error and significantly reduce the time to process and calculate these results.
“How Many Ways are there to Measure Moisture?”
That is a recurrent question in early discussions about moisture measurement problems. Is frequently asked in connection with specific products and applications. This is a basic primer on the main techniques.
Most Used Methods to Measure Moisture Content
There are four core methods. They include the use of heat, chemicals, electrical properties and electrro magnetic phenomena.
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.
CSC Digital Moisture Balance,
In past ramblings on particle size analysis we have touched on shakers, ASTM standards, sieve checking, separating small particles, inhibitors like static charges and how to get sieve tests done. A couple of things that we rarely addressed.
Particle Size Analysis,
Quiet sieve shakers,
The definition of Liquid Surface Tension is simple.
It's the force that keeps a liquid from flying off into space.
However, the measurement of surface tension can take many forms, which can be confusing. In an attempt to get some clarity, we have articulated two principle measurement concepts in this article: drop-based measurement and force-based measurement.
Automatic Digital Tensiometer,
Automatic Surface Tension Measurment,
Surface Tension Measurement,
du Nouy tensiometer,
surface tension instruments,
surface tension analysis
The first recorded application of density measurement was for fraud detection. The density measurement concept then expanded to encompass determination of material composition and assessment of product quality.