Introducing the all new Subsieve AutoSizer (SAS) II from Micromeritics

Micromeritics Subsieve AutoSizer (SAS) II

Developed as a direct and improved successor to the widely used Fisher Model 95 Subsieve Sizer (FSSS), the Micromeritics SAS II has improved the FSSS’s performance by offering easy-to-use automated functions together with electronically recorded data.

The SAS is designed to generate “Fisher number” results highly consistent with that of its predecessor (the Fisher FSSS). This is a crucial point, as the air permeability technique and the FSSS have been used as a benchmark for decades in many industries. Many applications use historical data and quality control standards, and a modern source of comparable, repeatable results is necessary.

What is Air-permeability Particle Sizing?

The air-permeability technique is well established for measurement of the Specific Surface Area (SSA) of a sample powder. The SSA measured by this technique has been found to be a useful parameter in various industries such as pharmaceutical, metal coatings, paints, and even geological samples.

The MIC SAS II utilizes dual pressure transducers to measure pressure drop across a packed bed of powder. By varying the sample height and porosity while controlling the flow rate of air through the sample, the SSA and average particle size can be determined using the Kozeny-Carman equation.

Features and Benefits

  • Superior Software – Sets a world-wide standard for instrument operation, data acquisition and handling, reporting and systems integration.
  • Quick and Easy Set-up – Simple step by step set-up, easy to follow; ensuring that no parameters are over looked.
  • Real Time Data Display – Data can be viewed as it is acquired simplifying method development.
  • Fisher Mapping – Optimizes data agreement with customizable Fisher correlation
  • ASTM Approval – Fully compliant with ASTM B330-12 and C721-14 standards for particle sizing of alumina, silica, and metal powders and related compounds. B330-15 – Metal Powders; C721-15 – Al2O3, SiO2 – Ceramics & E2980 – 15 – General particle size.
  • Fully Automated Analysis – Sample compaction and pressure stability are computer controlled for high repeatability.
  • Report Generation – Automatically creates PDF reports with custom company logos and typestyles.
  • Security Features – Optional password protection ties samples to user ID’s and protects configuration parameters from unauthorised change.
  • New Powerful Intuitive Touch Pad – User interface increases productivity and enables easy creation and retrieval of SOPs

Direct comparison of SAS and FSSS Results


Comparison trials between the Micromeritics SAS and Fisher FSSS have been carried out using a variety of samples. The graphs above compare the mean particle size data from the two instruments on powders of different sizes. One plot is based on results for inorganic (mainly tungsten) metal; the second on organic samples (mostly pharmaceuticals). There is exceptional correlation between the two sets of data. Numerous extensive studies have come to the same conclusion.