New particle size measurement technique uses air permeability for greater precision

August 22, 2017

New particle size measurement technique uses air permeability for greater precision

The Subsieve AutoSizer (Courtesy Micromeritics Instrument Corporation)

 

Micromeritics Instrument Corporation’s Particulate Systems Division, Norcoss, Georgia, USA, has announced a new instrument for the more precise estimation of the average particle size of powders. The new instrument uses an air permeability technique previously popularised by the Fisher Sub-Sieve Sizer, which is no longer available.

The Subsieve AutoSizer (SAS) measures the specific surface area of a powder by passing air through a packed powder bed and determining the pressure of the transmitted air by means of calibrated and traceable digital pressure transducers (also used for setting the packing force and input pressure) instead of the water-filled manometer standpipe (or bubble-rate pressure estimate, in the case input pressure) used in older methods. The specific surface area is then easily converted by the instrument to an equivalent spherical particle diameter using geometric and density considerations.

For over fifty years, the refractory metals, ceramics, lighting, other phosphors and pharmaceutical industries have relied on air permeability measurements to estimate the particle size of their materials. Some of these methods offer very imprecise results, leading to a large degree of rework and confusion in those industries. Because of its accurate and precise measurement of pressure by means of pressure transducers, the SAS reportedly provides much greater precision than traditional methods, allowing for appropriate particle size specifications to be set for both process and quality control, and for outgoing powder material specifications. The new instrument thus offers a fast and easily-obtained estimate of particle size in order to meet those specifications.

Several international standard test methods have been developed for use with the SAS, including ASTM Standard Test Methods B330 (for metals), C721 (for some ceramic materials) and E2980 (a general standard for particle size measurement of a wide range of materials). ISO Standard 10070, a general standard test method for this type of particle size measurement, is currently being revised for use with the SAS.

www.micromeritics.com

Recent issue of Powder Metallurgy review - your go-to resource to stay updated on the world of powder metallurgy and metal powders

In the latest issue of PM Review…

PM Review Spring 2023

Download PDF

Extensive Powder Metallurgy industry news coverage, and the following exclusive deep-dive articles and reports:

  • GKN Powder Metallurgy: A strategic vision for the future of permanent magnets for EVs
  • Building trust in the Powder Metallurgy industry: The role of standardisation and an update on recent work by ISO/TC 119
  • High-volume powder production for Additive Manufacturing: SMS group’s continuous metal powder production process
  • Development of enhanced-performance PM brake pads for high-speed trains by Beijing Tianyishangjia New Material Corp., Ltd.
  • The START project: Creating a sustainable supply chain for green energy harvesting products by Powder Metallurgy
  • World PM2022: Reviewing three innovative methods for metal powder production

The latest news from the world of metal powders, delivered to your inbox

Don't miss any new issue of PM Review, and get the latest industry news. Sign up to our weekly newsletter.

Sign up

Join our community

From the industry…

Discover our magazine archive…

The free-to-access PM Review magazine archive offers unparalleled insight into the world of Powder Metallurgy from a commercial and technological perspective through:

  • Reports on visits to leading PM part manufacturers, metal powder manufacturers and industry suppliers
  • Articles on technology and application trends
  • Information on materials developments
  • Reviews of key technical presentations from the international conference circuit
  • International industry news

All past issues are available to download as free PDFs or view in your browser.

 

Browse the archive

 

Looking for PM production equipment, metal powders, R&D support and more?

Discover suppliers of these and more in our
advertisers’ index and buyer’s guide, available in the back of PM Review magazine.

  • Powders & materials
  • Powder process, classification & analysis
  • PM products
  • Atomisers & powder production technology
  • Compaction presses, tooling & ancillaries
  • Sintering equipment & ancillaries
  • Post-processing
  • Consulting & toll sintering
Download PDF
Share via
Copy link