Are Your Measurements Fact or Fiction?

PoreSizer™ is a static image analysis system which measures particles, sieve meshes and filter pores. It uses an optical microscope and a high quality 1.4 megapixel camera, measures both size and shape, and includes a suite of detailed statistical and graphical outputs and pre-formatted certificates.

PoreSizer™ has been in development for a number of years and has gone through a rigorous validation process. It provides a transparent measurement process, which is traceable using certified reference standards, and is the foundation for the creation, verification and certification of all Whitehouse Scientific glass microspheres.

Image analysis is one of the internationally recognised primary methods of particle characterisation.

Charging and Expansion

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Video Support

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Operating Requirements

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PoreSizer™ displays measurement, live video, analysis and settings all on one screen, to make every function easily accessible. The system is easy to use, with extensive options for image adjustment, measurement calibration and statistical analysis of the results.

PoreSizer™ uses an optical microscope with a zoom lens and a 1.4 megapixel camera to capture slide images at 1392x1040 pixels. The live image can be digitally zoomed to focus on individual particles to achieve the sharpest possible image for accurate measurement.

Images can also be imported for measurement, e.g. from scanning electron microscopes (SEM) and transmission electron microscopy (TEM).

Particle size is determined by measuring the area of each particle and calculating the diameter of a circle that would occupy the same area (commonly known as the ‘Equivalent Circle Diameter’). PoreSizer™ also measures the maximum and perpendicular minimum axis, and particle perimeter.

Max axis
Min axis
Equivalent circle axis
Aperture X, Y
Aperture min, max
Aperture regularity
Wire size X, Y

Sieve aperture size is determined by measuring the maximum and minimum aperture dimensions. PoreSizer™ records the average of three measures in each direction. Aperture regularity refers to the aperture area versus the area of a square touching the aperture edges. The thickness of the wires is measured in the X and Y directions.

PoreSizer™ is a static image analysis system and can measure thousands of particles in just a few minutes. It automatically measures all particles on each slide, and includes algorithms to reject particle clusters, and particles touching the edge of the frame.

Sieve meshes can be analysed by measuring particle standards trapped by the mesh apertures, or measuring the mesh directly. PoreSizer™ records the maximum and minimum aperture sizes (taking three measures in each direction), the wire thickness (taking multiple measures in X and Y directions) and the wire count per inch.

Measurement is validated and traceable using certified reference standards and an NPL graticule. PoreSizer™ also includes a performance check workflow. This ensures the operator validates the selected calibration and image settings output the correct size, before measuring each sample.


PoreSizer™ includes a comprehensive suite of statistical and graphical outputs. The analysis can be tailored with multiple size and shape definitions, logarithmic and linear graphs, number and volume analysis and manual outlier removal. Data is saved in text files which can be imported into Excel for bespoke analysis, graphs can be saved as bitmaps, or printed as PDFs.



PoreSizer™ standard equipment

PoreSizer™ software (particle size and shape measurement, minimum size 2-3 microns)

  • 1.4 megapixel camera
  • Zoom microscope (12:1 zoom ratio, 3.97-0.01mm fov, infinity corrected, detented)
  • Microscope stand (fine/course adjustment)
  • x5 objective lens
  • Led illumination
  • Mechanical stage
  • Computer (mini PC, 16x10 monitor)

PoreSizer™ options

PoreSizer™ software (particle size and shape measurement, pore size challenge testing, sieve mesh measurement)

  • Whitehouse Scientific reference calibration microspheres for validation
  • NPL graticule
  • Precision sieve graticule
  • Additional objective lens (x2, x10, x20)
  • Low resolution microscope and macro stand for measuring sizes up to 10mm


PoreSizer™ can be purchased from the following distributers:

Porometer Ltd,

Begoniastraat 17,

9810 Eke,


Tel: +32 (0)9 252 25 35


Meritics Ltd,

1 Kensworth Gate,

200-204 High Street South,




Tel: +44 1582 704807