At Powtech 2010 (27-29 April, Nürnberg, Germany) Whitehouse Scientific will exhibit the company’s new opaque standards for particle size analysis. Managing director Dr Graham Rideal will also present a lecture as part of the World Congress on Particle Technology (WPCT6), a scientific congress which this year takes place alongside Powtech. He will focus on the latest trends in particle size standards, from sub-micron multimodal standards to Image Analysis standards up to 2 mm in size.

Whitehouse Scientific’s new silver-coated opaque standard covers the size range from 19 to 190 microns. It has been the subject of a recent round-robin exercise involving examination by leading particle sizing laboratories and instrument manufacturers. Importantly, the new standard has been analysed within the Quality Audit Scheme of independent company LGC Standards, and has produced the best ever repeatabilites seen by laser diffraction analysers.

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.

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.
 

Whitehouse Scientific sponsors Philippines football team at Street Child World Cup

Whitehouse Scientific is sponsoring the Philippine’s national team at the first ever Deloitte Street Child World Cup. Street children representing nine countries will gather in Durban, South Africa from 14-23 March 2010, to play football and raise awareness towards gaining rights for street children all over the world. Donations for this cause can be made via the Amos Trust website at: www.streetchildworldcup.org

For many years Whitehouse Scientific has been an active supporter of children’s charities, from Children in Need in the UK to children’s work in Mongolia. In particular, over the last five years, the company has had a special relationship with the Mango Tree children’s home in Manila, which does a phenomenal job in rescuing disadvantaged children who find themselves in need or on the street.
 

Left: Dr Rideal 
Right: Gary Mabbutt,
former Tottenham Hotspur Captain
and England International

“The first stage is to gain their confidence” says managing director Dr Graham Rideal, who uses the universal language of music (his tenor sax) to get their attention. “Although they love Rock and Roll music, I was amazed that they know all the words to love song classics such as ‘I will always love you’” said Graham following a recent visit. Once a dialogue is established with local social workers, there is a good chance that a street child will be accepted into Mango Tree House.

Once in a stable and safe environment, there are so many opportunities for the children to blossom. In this Football World Cup year, boys and girls, both in homes and still on the streets of Manila, compete for places in the parallel world cup for street children. There can be no higher honour than representing your country at sport and so every place is fiercely contested.

“It has been tremendously fulfilling to think that I have played a small part in changing the lives of some of these children”, says Graham, who is now actively engaged in raising money to send the team across to Durban in South Africa.

This Deloitte Street Child World Cup marks the launch of a new Amos Trust initiative aimed at both celebrating the potential of street children, and providing a platform from which they can be heard. Those interested can also tune in to Blue Peter on BBC One to follow the action as presenter Andy Akinwolere mentors the British team.

Whitehouse Scientific produces precision glass microspheres for calibration and is the world's leading manufacturer of single-shot glass microsphere standards. Further information on primary methods of particle size analysis, as well as the company’s contribution to children’s causes can be found at: www.whitehousescientific.com

Record attendance at Filtration Society meeting
Record numbers of people attended the most recent of the Filtration Society’s popular one-day technical meetings. Held in Chester (UK) on 19 November 2009, the meeting focused on advances in filter media. Seven speakers and representatives from 11 exhibiting companies joined the 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 a great deal of interest.

The Filtration Society’s Science Correspondent Dr Graham Rideal, is pleased that the programme appealed to such a wide audience. “Our one-day technical meetings have become enormously popular and now attract delegates from around the world,” he said. “In today’s climate, if you take a day out of your schedule to attend a conference, you need to be confident that it is time well spent. When arranging the programme for these meetings we aim to deliver focused content that provides a uniquely valuable day for those who need to know about specific aspects of filtration. Positive feedback from delegates suggests that this really is a successful approach.”

The Filtration Society’s one-day meeting format, from which all delegates receive a bound set of notes, is proving highly successful, with attendee numbers growing year on year. Delegates are drawn from many areas, including process engineers, designers, technical and R&D personnel, research institutes and industry decision makers.

Filtration Society Autumn meeting focuses on advances in filter media

A one-day international technical meeting of the Filtration Society - Filter Media 4: Cost-effective solutions – is being held on Thursday 19 November 2009 in Chester, UK, to review the latest developments in the field. Speakers from Northdoe Ltd, Camfil Farr, Freudenberg Vliesstoffe, Porvair, Bekaert, Hollingsworth and Vose, and Europlasma will cover various aspects of filter media development, from markets and trends through to the latest high performance low pressure drop glass media.

Dr Graham Rideal of Whitehouse Scientific is Science Correspondent for the Filtration Society. “In the two years since we last held a meeting on filter media there have been many developments for both gas and liquid applications,” he said. “The meeting will feature key elements including the role of design, recent products borne out of industrial R&D, and case studies exemplifying modern filter media technologies.”

The Filtration Society’s one-day meeting format, from which all delegates receive a bound set of notes, is proving highly successful, with attendee numbers growing year on year. This meeting is expected to be especially useful for process engineers, designers, technical and R&D personnel, research institutes and industry decision makers. A trade exhibition will run alongside the conference programme.

Attendance is open to both members and non-members of the Filtration Society. For more event details, rates and registration visit:
 

Dr Graham Rideal, managing director of Whitehouse Scientific, will deliver a paper at Filtech 2009 describing ‘A new method of measuring pore size distributions using multi-modal particle size standards’. The work is being presented as part of the session on Filter Media Characterization and describes a novel technique developed by Graham Rideal and Jamie Storey of Whitehouse Scientific in collaboration with Dr B Schied of BS-Partikel in Germany. Filtech is an international conference and exhibition covering filtration and separation technologies and this year takes place from 13-15 October 2009 in Wiesbaden, Germany.
 

Introducing Multimodal Standard for high resolution particle sizing instruments

27 March 2009; Chester, UK: As particle sizing methodologies grow ever more sophisticated, it is becoming increasingly 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.

At ACHEMA 2009 (11–15 May; Frankfurt, Germany) Whitehouse Scientific will launch a new Multimodal Standard that 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.
 

Whitehouse Scientific has initiated external testing of a new particle size standard. The company has produced a 500kg batch of silver coated glass microspheres in the size range 15 to 150 microns. The first of its kind, this opaque standard is expected to have universal application and be compliant to the latest ISO and USP standards.

LGC Standards (Bury, Lancashire, UK) will carry out the statistical analysis of test results. Dr Graham Rideal, managing director of Whitehouse Scientific, feels that their involvement is an essential part of the testing process. “LGC Standards has an international reputation in the field of proficiency testing and has run many schemes over the years. Their independence in this type of exercise is really important, not only because of their experience, but also in maintaining anonymity of the test data. LGC Standards will be able to provide a statistically robust set of final certified values, which we hope will be recognized as being truly independent,” he said.

Subdivided into single-shot bottles from 2.5g down to 100mg, the opaque standard is suitable for all particle sizing methods, from laser diffraction and image analysis to optical zone sensing devices, and for both wet or dry analyses.

For more information about the standard or the current testing programme contact rideal@whitehousescientific.com 
 

A recent study carried out by Whitehouse Scientific exposed an imported sieve mesh as falling far short of its 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 tested was purchased as a ‘precision mesh’. Calibration using the 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 also confirmed by microscopy.

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

Whitehouse Scientific team wins Ray Mears experience in Terry Wogan’s Children in Need  auction

Having successfully bid in this week’s Children in Need auction on Terry Wogan’s Radio 2 breakfast show for the ‘things money can’t buy’, Whitehouse Scientific’s Graham Rideal and Jamie Storey are preparing to spend three days in Saskatchewan adventuring with survival expert Ray Mears, on the set of his new TV series.

Having seen active service with the Territorial Army, taken part in an Everest Base Camp walk, and successfully completed this year’s gruelling Mongol car rally, Lab Manager Jamie Storey is not one to shy away from a challenge and can’t wait to get started.

Accompanying him will be managing director Graham Rideal. While Graham is perhaps best known for his expertise in calibration matters, he is also an active worker for children’s charities in the UK and overseas. “We are always big supporters of Children in Need, but this was an irresistible opportunity to make a contribution and have a truly unique experience,” he said. “Bush-craft and outdoor activities are what we’re being promised, but I think it may be a step up from my boy scout days!”

The trip will take place around March next year, when it is promised that the weather will be “very, very cold”.

Organisers are celebrating the success of the most recent Filtration Society Conference, held in Chester on 28 October 2008. Around 80 international visitors attended the one-day ‘Filter Testing and Standards’ conference, which was sponsored by Whitehouse Scientific and supported by a ‘full to capacity’ trade exhibition. It examined the latest developments in filter testing and characterisation and their relation to quality standards

Dr Graham Rideal who heads the organising committee is delighted that the conference is becoming an increasingly important networking opportunity for anyone involved in filtration. “It was standing room only in some of the sessions,” he said, “and I was particularly pleased to hear comments from delegates and exhibitors that this is one of the friendliest conferences they come to. The high quality presentations give really useful, practical information and the format of the event allows plenty of opportunity to exchange views with colleagues in the industry.”

Another popular feature of the day was the poster session in which delegates received a ‘5-minute burst’ of information on a wide range of filter testing techniques.

Further one-day events scheduled for 2009 include: Regulatory issues in environmental control; Reducing the carbon footprint of filtration; and Recent developments in filter media. Full details are available at www.filtsoc.com

At Analytica China (23-25 September 2008, Shanghai) Whitehouse Scientific is focusing on its solutions for sieve calibration. The company produces a range of narrow size distribution, NIST-traceable ‘single-shot’ glass microspheres to a maximum size of 10 mm, specifically designed for calibrating sieves. Full guidance for their use is available on the company’s website, together with a freely downloadable sieve aperture calculator.

The glass microsphere method is the most unambiguous way of calibrating sieves according to their performance. Having only one dimension, microspheres either pass through or are retained by the sieve. For the test process, a vial of the beads is shaken on the test sieve for one minute and the percentage passing through is used to calculate the aperture size. The weight of beads in each vial is calculated to ensure that more than 80% of the sieve apertures are covered during calibration. This ‘single shot’ approach additionally removes the possibility of operator error through poor sub-sampling from a larger bulk of microspheres.

2008 is a special year for Whitehouse Scientific as the company celebrates its silver anniversary, having now produced and certified glass microspheres for 25 years. In that time the company has become established as the leading laboratory for glass reference standards and has produced more than one million single-shot bottles.
 

 
Whitehouse Scientific launches new opaque size standards
at PSA 2008

Following the success of the company’s

10–100 micron polydisperse clear glass standards, Whitehouse Scientific has prepared a new 500 kg batch of an opaque version of the glass beads. These will be on show at Particulate Systems Analysis 2008 (PSA 2008) being held from 2–4 September in Stratford-upon-Avon, UK.

The particle size standard is subdivided into single-shot bottles from 2.5 g down to 100 mg making it suitable for all particle sizing methods, from laser diffraction and image analysis to optical zone sensing devices analysing either in the dry state or as a suspension. 

The standards are all NIST traceable and have been analysed by more than 20 laboratories covering a range of techniques including laser diffraction, image analysis and sieve analysis.
 

The latest additions to the Whitehouse Scientific range of sieve calibration standards will be shown on the company’s stand at this year’s Analytica (1-4 April 08, Munich, Germany). The size range covered has been further extended, increasing the maximum size from the previous 3.35 mm diameter to 10 mm.  

2008 is also a special year for Whitehouse Scientific as the company celebrates its silver anniversary, having now produced and certified glass microspheres for 25 years. In that time the company has become established as the leading laboratory for glass reference standards and has produced more than one million single-shot bottles.

Whitehouse Scientific has also developed a new method of pore size analysis in filter media, measuring sizes from 5-1000 microns. Where filter efficiencies are required, maximum pore sizes down to 3 microns can be determined. 

All the standards, whether used for size calibration or pore size determination are NIST traceable. Visit Stand No: A1/357 to discuss your particle analysis or filtration calibration needs.

Whitehouse Scientific has responded to an increased interest in automated measurement of large particle sizes by introducing single size glass beads of greater than 1 mm in diameter. Traditionally, sieve analysis has been used for such large sizes, which are also near the upper limit of some laser diffraction methods of analysis. As image analysers now have a firm foothold in this sector, there is a requirement for NIST traceable reference calibration beads. The Monodisperse Standards have very narrow particle size distributions and come in sets of five single shot bottles, together with a NIST traceable test certificate. Application areas include pharmaceuticals, foodstuffs, polymers and speciality chemicals.

Whitehouse Scientific launches new E-brochure
To help customers order from the constantly expanding range of particle size calibration standards, Whitehouse Scientific has introduced a new E-brochure onto the company’s website. Whether the interest is in Polydisperse, Monodisperse or Sieve calibration standards, a single page brochure containing technical information and prices can be downloaded directly from the website. There is also a brochure for the recently introduced black Basalt beads. For those interested in more detailed scientific information, the Whitehouse Scientific library now contains 40 technical papers by the founder Dr Graham Rideal, and remains one of the most visited areas on the site. 

Whitehouse Scientific will unveil an attractive and highly practical new look for the company’s microsphere standards at Powtech 2007 (27-29 March 07; Nűrnberg, Germany) as it introduces a new packaging design throughout its extensive product range. The presentation of the standards has been completely updated with the introduction of new, more durable plastic bottles, individually held in foam and supplied in a clear plastic display case. At the associated Partec conference Dr Graham Rideal, managing director of Whitehouse Scientific, will also present a paper on the use of Whitehouse standards for image analysis.

Whitehouse Scientific has been producing glass microspheres for calibration for 24 years. The company is the highest ranking European certification laboratory for primary methods of particle size analysis and the world’s leading manufacturer of single-shot glass microsphere standards. The reference standards, nearly all of which are NIST traceable, range in size from 0.1 µm to 5.0 mm and are available as single size or broad distributions. Whitehouse also offers a unique calibration procedure for NIST-traceable measurement of filter apertures. 

Dr Rideal and members of the Whitehouse team will be available on the Whitehouse Scientific stand Hall 8/201 at Powtech 2007 to discuss individual calibration requirements.

Whitehouse Scientific will introduce a new filter efficiency test at Filtech 2007 (27 Feb – 1 Mar 2007; Wiesbaden, Germany). Using fine silica glass beads of 1.5, 2, 3, 4.5, 5 and 6 µm diameter, the new test enables measurement down to very fine pore sizes. The Whitehouse approach allows full NIST traceability, something that in the past has presented a challenge for users of fine pore size filters.

To perform the test, standards are made into a dilute aqueous suspension which is drawn through the filter medium using a simple vacuum system. Efficiency is measured by determining the percentage of standard retained in the filter.

Dr Graham Rideal, managing director of Whitehouse Scientific and former chairman of the Filtration Society, will also present a conference paper on 28 February, entitled: Challenge testing by precision glass microspheres – a new physical method of measuring pore sizes. He and other members of the Whitehouse team will be available on the company’s exhibition booth to discuss individual filter testing requirements

After two very successful years, the mantel of the chairmanship of The Filtration Society has been passed from Graham Rideal of Whitehouse Scientific to Lloyd Holiday of Larox. During his term of office, Dr Rideal saw the biggest growth in numbers of Corporate Associates of the Society in the organisation’s 40 year history.
 

A major factor contributing to the success of the Society has been its organisation of up to four one-day technical meetings each year, at which highly relevant and state-of-the-art information can be exchanged. The most popular series is centred around filter testing, and these meetings regularly attract international audiences from more than 10 different countries.
 

Lloyd Holiday brings to the office a large international network of his own and highly respected organisational skills. He will continue to build on the success of recent years to grow and further develop the activities and reputation of the Filtration Society.

Dr Graham Rideal (left) outgoing chairman of the Filtration Society with new chairman Lloyd Holiday (right)

Whitehouse Scientific, one of the most widely recognised and respected manufacturers of particle size calibration standards using glass microspheres, has added basalt microspheres to its range 

The transparency of standard glass microspheres presents problems for some particle sizing systems and technologies. Being opaque, the new basalt standards provide an alternative and long term solution. 

There are over 20 individual narrow distribution grades each with excellent sphericity, ranging in size from 50 microns up to 2 millimetres.  The calibration standards are supplied in convenient 100g lots.

Available for immediate purchase, the new basalt microspheres are designed for use in both lower grade and initial research applications. Should additional classification be required, this can be carried out on request to provide a higher grade certified standard with NIST traceability.

Sustained high demand has led Whitehouse Scientific to issue a new batch of the company’s NIST traceable glass microsphere standards for use with particle image analysis systems.

Four standards cover the range 50 to 5000 microns and are available in weights from 50 to 500 grams. They are calibrated by precision sieving methods and are traceable to international standards of length such as NIST and NPL. The standards have been developed to provide excellent resolution at the extremes of the size distribution.

Whitehouse Scientific’s managing director Dr Graham Rideal commented: “Particle characterisation by image analysis is becoming increasingly popular. It offers rapid analysis and provides unique information on particle shape. As a result we are seeing a high demand for standards which we anticipate will continue to grow.”

One-day Filter Testing conferences are amongst the most popular events organised by the Filtration Society. They usually attract in excess of 100 delegates and around 25 exhibitors from all over Europe.

This year’s event, which will be held on 3 October 2006 at the Coventry Transport museum (UK), may prove to be the most popular ever, as it revolves around ISO test methods.

The conference, organised by Dr Graham Rideal, chairman of the Society and MD of Whitehouse Scientific, will discuss all the major pore size measurement methods for wet and dry filtration. The sessions will be presented by leading European experts.

As well as the seven principal lectures, a poster session comprising ten short presentations and a comprehensive exhibition will ensure delegates are made fully aware of all the latest filter testing technologies.

As a bonus, delegates will receive free entry to the museum where they can see vehicles ranging from the first cars ever produced to Thrust, a supersonic land speed record holder.

The on-site calibration of test sieves has been further simplified by the introduction of new software from Whitehouse Scientific. Every sieve manufactured from 20 to 3350 microns, ranging in diameter from 40 to 450 mm, can now be unambiguously calibrated.

The new program will be provided free of charge to customers purchasing the company’s calibration standards. It allows the calculation of sieve apertures directly from the weight of glass calibration beads passing through the sieve. To determine the mean aperture size, the operator simply selects the nominal rating of the sieve to be calibrated and enters the initial weight and the weight of the beads passing through.

Using the new program it is possible to measure more than 80% of available apertures, with full NIST traceability, in under two minutes. The speed, simplicity and reliability of the Whitehouse procedures have eliminated the need to return sieves to the manufacturer for recalibration
 

Building on the continuing success of the company’s glass microsphere sieve calibration standards, Whitehouse Scientific has now extended the range and resolution of the series.

The aperture size of every sieve manufactured from 20 to 3350 microns can now be certified to NIST traceability. This extends the range’s capabilities from the 30 'primary' sieves that originally could be calibrated to include a further 30 intermediate sizes.

This new development is important not only in precision particle size analysis, but also for accurate separation processes. It is now possible, for example, to accurately distinguish between a 100 and a 106 micron sieve.

The Whitehouse sieve calibration standards are available in single shot bottles, minimising the possibility of sampling errors by the operator. They can be used for sieve diameters from 40 – 450 mm diameter.

Sales growth and increase in online purchasing for Whitehouse Scientific

Whitehouse Scientific has introduced an enhanced secure ordering and payment system on its website. With sales growing 20% year on year, the new system is designed to meet increasing worldwide demand for credit card purchase of the company’s calibration standards via the website.

Managing director Dr Graham Rideal anticipates a continued growth in demand for the high precision particle size, image analysis, filtration, sieve and other calibration standards for which Whitehouse has gained an international reputation.

“The technologies that our products support are now critical to the efficiency of a wide range of research, development and production processes,” he said. “The investment in and the application of these technologies may be highly significant in terms of financial and human resources. Ensuring that they perform properly and with maximum efficiency, reliability and traceability makes sound economic sense and our calibration standards and methodologies are part of this process.”

Whitehouse will introduce a number of novel products and line extensions in 2006, several of which will be launched at Analytica in Munich in April and ACHEMA in May.
 

Whitehouse Scientific MD appointed to serve 2nd term as Chairman of the Filtration Society

Dr Graham Rideal, managing director of standards and calibration company Whitehouse Scientific, has been elected to a second consecutive term as Chairman of the Filtration Society.

“The past year has been a busy, and I believe successful, one for the Filtration Society as we extend our activities and our international connections. I’m certainly looking forward to continuing that process,” said Dr Rideal. “Last year the Society and its members supported a wide variety of major industry events around the world, including the American Filtration Society/AIChE joint conference, HVAC Vietnam and HVAC China, FILTECH 2005 in Germany and Filtration 2005 in Chicago. As well as this, our own programme of seminars and technical meetings held in the UK has really taken off. We received tremendous support from the membership for our one-day meetings, which last year covered topics ranging from the use of filtration technologies to increase profits and reduce costs, to improving process efficiency through filter scale-up and evaluation. These events will be continued in 2006.”

The Filtration society http://www.filtsoc.com Is a charitable, non-profit making organisation which aims to advance and disseminate knowledge in the design and use of filtration and separation techniques. It has members in more than 25 countries around the world.
 

5 December 2005
 

Whitehouse Scientific lab manager resumes role after overseas posting

Whitehouse Scientific is welcoming back Jamie Storey who has worked for the company as Laboratory Manager since graduating from Newcastle University in 1999.  As a member of the Territorial Army, Jamie was called up in 2004 to serve overseas with the Royal Fusiliers of Tynemouth. Following this posting, he spent a number of months fulfilling some of his lifetime ambitions, including trekking to Everest base camp and following the Machu Picchu Inca trail in Peru. 
 

Jamie returns to Whitehouse Scientific in January 2006, where he will not only continue to manage the laboratory, but will also have a prominent role at conferences and exhibitions, and will be involved in generating technical materials for the company.
 

Whitehouse Scientific has further extended its range of filter pore size standards, with the inclusion of standards down to 0.5 micron.

These narrow distribution glass microspheres are used to ‘challenge’ filter media. Analysing the proportion of spheres passing through the filter enables determination of the maximum pore sizes present.

For pore sizes of greater than around 15 microns, the percentage of dry microspheres passing through can be related directly to pore size, simply using a calibration graph, and without the need to use particle size analysis. For pore sizes of below about 15 microns a wet suspension method is used and this extends the range to submicron regions. 

All measurements provide unambiguous results and are traceable to international standards of length, such as NIST.
 

One of the largest ever series of round robin tests, where a number of different laboratories analyse the same materials, has now been performed on Whitehouse Scientific's polydisperse particle size standards.

Under the auspices of the Laser Diffraction Proficiency Testing Scheme (LDPTS) more than 60 laboratories analysed four glass microsphere particle size standards covering the size range from 1 - 350 microns. While a number of testing laboratories produced results that were in excellent agreement with the certified standards, some showed significant deviations.

This work highlights the need for reference standards in combination with prescriptive methods of analysis. It also explains why there has been a significant surge in the use of such materials in laboratories performing precision particle size analysis.
 

New pore size measurement for air filters
Whitehouse Scientific, a leader in the field of particle size standards, sieve calibration and filter testing, has developed a new device for measuring the retention properties of filter elements in compressed air lines. The principle of the technique is to challenge the air filter with a dilute suspension of glass microspheres, drawn through a vibrating filter under vacuum. The particle size of the microspheres passing, as measured by microscopy and image analysis, provides an unambiguous measure of the cut point of the filter. This is especially important in critical applications such as pharmaceutical processing.

Hitherto, the performance of such filter elements could be measured only in sheet form. When fabricated into three-dimensional forms the retention properties could be seriously compromised. This is exemplified by tests performed in Whitehouse’s laboratories, where a five micron filter tested as a conical cylinder allowed the passage of microspheres of up to 130 microns in diameter.

Unique to the Whitehouse method is the use of narrow particle size distribution standards which give extremely accurate results that are traceable to NIST. Maximum pore sizes from more than 1 mm down to 3 microns can be measured.
 

Whitehouse Scientific’s sonic method of measuring the pore size distribution of a filter medium is being widely adopted for the certification of sand screens used in oil wells. Many major oil companies are now specifying the Whitehouse method to optimise the pore size of the screens, in order to maximise oil flow while retaining harmful sand. The accuracy and reliability of the Whitehouse method helps reduce the possibility of costly pipeline failure.

The incorrect specification of sand screens in oil wells can lead to ‘plugging’ or pipeline erosion. This effectively terminates oil production. With oil rig hire costing in the region of US$250,000 per day, re-drilling another bore hole of up to 15,000 metres can mean in costs in excess of US$20 million for ‘junking’ an oil well. Last year 14 wells in the South China Sea were ‘junked’ at a cost of $300 million simply because the pore sizes of the sand screens were incorrectly specified.

Whitehouse’s sonic method of pore size analysis allows the measurement of filter efficiency and assesses the pore size distribution across the entire filter medium. Measurement of pore size and the ability to distinguish between ‘open’ and ‘closed’ pores has also enabled subtle differences in filter media to be understood. The method is currently applicable to pores from 50 to 1000 microns.
 

Whitehouse Scientific MD joins Filtration News’ editorial advisory board

Dr Graham Rideal, managing director of Whitehouse Scientific and current chairman of the Filtration Society of the United Kingdom, has been appointed to the editorial advisory board of the US-based publication Filtration News.  

Dr Rideal, whose specialisation in this role is filter and media validation, is the only board member from outside the United States of America. As well as acting in an advisory capacity, he will also contribute a number of papers and articles to the publication. “I am very pleased to have been invited to join this respected group and to be able to play a role in the development and output of Filtration News,” he said.

Dr Rideal has recently developed a new and unique method for the measurement of filter cut points by the use of precision glass microspheres. These new standards can measure filter pore sizes with an accuracy of better than 1 micron with results traceable to International standards of length such as NIST (National Institute of Standards and Technology, USA).

For more information about Whitehouse Scientific please visit www.whitehousescientific.com and for information about Filtration News www.filtnews.com
 

Whitehouse Scientific has introduced a new 500 to 2000 micron particle size standard designed specifically for use with image analysis systems.

While the standard appears as a smooth Gaussian distribution using sieve analysis, it actually incorporates fine structural details that can be seen only by high resolution image analysers.

The new standard has been certified using Electroformed Sieve Analysis and Image Analysis. Both techniques are traceable to the NIST and NPL international standards of length.