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CSC Scientific Blog

Sieves – Old and New QC Issues

Posted by Art Gatenby on Jul 6, 2011 3:13:00 PM

In April, we published an article in "Powder-Bulk Solids" comparing certification process veracity with a sieve calibration process using calibrated glass microspheres (or beads). The certification process merely indicates that a sieve mesh conforms to a standard that has a wide tolerance regarding mesh openings. It is performed on a small number of openings. On the other hand, calibration using the calibrated beads results in a number representing the mean opening -- a result generated by actually performing a test encompassing at least 80% of the mesh openings.

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Topics: Sieve Shakers, Calibration, Particle Size Analysis, Sieve Calibration, Sieve Certification, Sieve Testing, Sieves, Sieving Process

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

Why Not A Bostwick Consistometer Calibration Standard?

Posted by Art Gatenby on May 11, 2011 12:35:00 PM

Customers want Bostwick Consistometer Calibrations.

When told that CSC Scientific does not calibrate Bostwick Consistometers, people ask .Then how can I calibrate my consistometer and where can I get a calibration standard?”.

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Topics: Bostwick Consistometer, Consistency, Calibration, Liquid Properties

Surface Tension – Tensiometer Update

Posted by Art Gatenby on Apr 29, 2011 2:11:00 PM

This ramble is about changes in the Surface Tension Equipment landscape.

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Topics: duNouy Rings, Tensiometer, Surface Tension Measurement, Surface Tension, Interfacial Tensiometer, Fisher Tensiomat, Liquid Properties

Loss-On-Drying Moisture Analysis and Other Moisture Mysteries Part IV: Water Activity

Posted by Art Gatenby on Mar 31, 2011 3:39:00 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 these realities, I offered to enter the world of witchcraft and folklore; water activity.

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Topics: Bound Moisture, Moisture Sorption Isotherm, Moisture Analysis, Water Activity, Loss-On-Drying

Who's Concerned About Sieve Shakers?

Posted by Art Gatenby on Mar 11, 2011 12:33:00 PM


The primary purpose of a sieve shaker is to provide motion to a sample in a test sieve.

An effective sieve shaker creates a motion that presents all the particles to all of the sieve openings and assists particles in passing through. This requires both rotary and vertical motion.

This process seems simple enough, but let's not be taken in.

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Topics: Sieve Shakers, Particle Size Analysis, Sieve Testing, Sieves

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

How Does Surface Tension Relate to Viscosity?

Posted by Art Gatenby on Jan 17, 2011 9:58:00 PM

You may recall that I promised to offer my interpretation as to how Surface Tension is related to Viscosity.

To begin with, liquid surface tension and viscosity share a common trait: they both involve properties of fluids. After that, things start to get murky.

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Topics: Wilhelmy Plates, Viscosity, duNouy Rings, Tensiometer, Surface Tension Measurement, Surface Tension, Interfacial Tensiometer, Liquid Properties

Loss On Drying Moisture Analysis and Other Moisture Mysteries II Vapor Pressure

Posted by Art Gatenby on Nov 22, 2010 5:55:00 PM

A while ago on these pages I agonized about loss-on-drying moisture analysis . As you may recall, my explorations of the drying process overwhelmed me with evaporation concepts , vapor pressure notions, water content complexities and water activity witchcraft, all just to dry something.
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Topics: Evaporation, Moisture Analysis, Moisture Testing, Loss-On-Drying

Having Trouble Performing a duNouy Ring Test in Thick Samples?

Posted by Art Gatenby on Nov 15, 2010 3:29:00 PM

My musings were interrupted this week with a pressing challenge. It was stated like this:

 “My duNouy ring kept falling off the arm hook when attempting to immerse it into a high-viscosity sample.”

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Topics: duNouy Rings, Surface Tension Measurement, Surface Tension, Interfacial Tensiometer, tensiometers, Liquid Properties

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