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MORE PRODUCTS FROM WHITEHOUSE SCIENTIFIC


New Method of Measuring Filter Pore Size Distribution


Whitehouse Scientific has developed a unique range of calibration microspheres for measuring the pore sizes of filters from over 1000 microns down to 0.1 micron. Different systems of challenge testing are used depending on the filter cut points. Above 20 microns, a high speed dry Sonic Filter Tester is used, while a wet ultrasonic system takes the measurement down to 2 microns using a combination of microscopy and narrow size distribution silica microspheres. In the sub- micron range a ‘Multimodal’ standard comprising of 10 non-overlapping latex microspheres in conjunction with a Disc Centrifuge can measure both filter cut points and pore size distributions.


Multimodal standard for determining filter pore size distribution Circle no. 521


Following the success of the 9 micron glass microsphere standard, Whitehouse Scientific has introduced a new range of Monosized silica microspheres from 10 microns down to 1.5 microns.


Whitehouse Sieve Standards Expose Inferior Mesh A study conducted by Whitehouse Scientific


exposed an imported sieve mesh as falling short of claimed performance specifications. Since many such meshes are used in critical industrial applications, these findings illustrate the importance of strict checks and calibration using proven methods.


The mesh was purchased as a ‘precision mesh’. Calibration using Whitehouse Scientific sieve standards revealed it to be an inferior product compared with its competitors, even though it had the same mesh rating (number of wires per inch). This finding was confirmed by microscopy.


The accuracy of Whitehouse Scientific’s sieve calibration microspheres allows detection of subtle performance differences even when microscope analysis might suggest different meshes are identical. The technique can be used even on the highest quality electroformed sieves.


Circle no. 522


Using a highly specific microscope certification procedure, all the silica standards are traceable to NIST and NPL international standards of length. They are available in sets of 10 bottles each containing 0.2 g of dry powder, either all the same size or as a mixed set as specified by the user. A certificate of analysis is enclosed.


Applications of the silica microspheres include filter testing, spacing applications and as respiratory or drug delivery models for the pharmaceutical industry.


Circle no. 524


New Monosized Silica Microspheres


Record Attendance at Filtration Society Meeting


Multimodal Standard for High Resolution Particle Sizing Instruments


As particle sizing methodologies grow ever more sophisticated, it is becoming increa - singly difficult to measure the degree of resolution offered by the latest instruments. Image analysis methods, for example, offer one of the highest resolutions available today but until now it has been difficult to quantify the resolution.


Whitehouse Scientific’s new Multimodal Standard is designed to address this challenge. In this standard, eight distinct peaks have been produced between 500 and 2000 microns. For very small particle sizes, a Multimodal Standard with ten peaks between 0.1 and 1.5 microns has been prepared for evaluation.


Circle no. 523


At the Filtration Society’s one-day technical meeting on advances in filter media held last November, seven speakers and representatives from 11 exhibiting companies joined 70 delegates for a programme that ranged from an update on filter media markets, through filter classification and regulatory requirements, to details of the latest high performance media. A well subscribed poster session featuring 5-minute oral presentations also attracted considerable interest.


“Our one-day technical meetings have become enormously popular and attract delegates from around the world,” said Graham Rideal, Science Correspondent for the Filtration Society. “We always aim to deliver focused content that provides a uniquely valuable day. Positive feedback from delegates suggests that this really is a successful approach.”


For details of Filtration Society events visit www.lboro.ac.uk/departments/cg/research/filtration/t echnical_meetings_2010.htm


Circle no. 525


LABMATE UK & IRELAND - JANUARY/FEBRUARY 2010 - ADVERTORIAL


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