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Technical Article: Temperature Influences on Measurement Accuracy

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Technical Article:
Temperature Influences on Measurement Accuracy


Writing for Manufacturing Engineering magazine, a publication of The Society of Manufacturing Engineers, Colin Robinson, Eastern Regional Metrology Manager for Vision Engineering Inc., discusses the effects of temperature influences on measurement accuracy …

Read the full article here:

http://www.sme.org/cgi-bin/find-articles.pl?&08jum003&ME&20080601&&SME&#article

Kestrel Ensures Blood Processing Medical Devices are in Specification

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Kestrel Ensures Blood Processing Medical Devices are in Specification


Gambro BCT are using a Kestrel non-contact measuring system to measure and inspect a wide range of medical device components as well as mould tools used in their manufacture.

Gambro BCT is a global leader in automated blood collection technologies. The UK headquarters in Gloucester is the European production centre for blood component technology disposables. These devices are used in the innovative new OrbiSac system, a machine developed to extract platelets from blood products. Platelets are increasingly in demand for donation to patients who are suffering from a variety of illnesses where these repair cells have been destroyed by disease or treatment.

 

 

Critical Devices

The disposable device used in the OrbiSac system is a complex assembly of several PVC tubes and soft PVC collection bags, assembled using precisely toleranced and quality controlled components. Whenever a platelet donor gives blood, a new, sterile collection system must be used. Due to the critical nature of the device, quality and functionality must be guaranteed with each device being carefully controlled and inspected during manufacture.

The Kestrel system is operated within the ENISO 14664-1 Class 8 standard clean room. The regular task that falls on the Kestrel is the accurate gauging of PVC tubing used within the disposable device. 1km reels of PVC tubing are delivered to Gloucester, where every batch is then sampled for accurate inner diameter (ID) and outer diameter (OD). A slice of tubing is examined on the Kestrel’s XY stage, allowing extremely accurate measurement of the diameter.

Adrian Mann, Senior Engineer commented that “the Kestrel offers significant benefits over conventional contact gauging methods. The PVC tubes are quite flexible so accurate, repeatable gauging is very difficult when using a number of inspectors”. The Kestrel is connected to a QC200 microprocessor, so operators follow a basic operating procedure and input points on the tube diameter using the simple to use keypad. Adrian continues “…for basic inspections, the system couldn’t be simpler. The operators multi-task throughout the production cell. This way, I don’t need to have a specialist engineer to carry out the measurements.”

 

 

Flexibility, Accuracy and Ergonomics

To ensure the best possible seal in the collection bags, an RF (radio frequency) welding technique is used. This provides a strong, water tight seal that is stronger than the bag itself. A secondary measurement task for the Kestrel is the gauging of the RF brass mould tools. These measurements allow the Kestrel to demonstrate its flexibility and accuracy, by allowing an engineer to measure the precise features of the brass mould tool against the original engineering drawing. Because of the true optical image used by Kestrel, edges and features are clearly contrasted in the viewing head, allowing edges to be precisely located despite being brass against brass.

Another advantage of the ergonomically optimised system is the large eye relief distance offered by the display head. The Gambro operators must wear eye protection to guard against any possible risk of solvent splashes. Kestrel allows safety glasses or prescription glasses to be worn, unlike conventional microscope eyepieces. This means that not only is the unit comfortable to use, operator safety is also assured.

Adrian Mann concludes “I’m very happy with my choice of measuring system; Kestrel has provided a flexible solution that is popular with the operators. Not only is it compact and simple to use, but it’s also very good value for money!”

Swiss Machined components

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Swiss Machined components

Rowan Precision are using Vision Engineering’s Kestrel manual 2-axis and Hawk 3-axis fully automatic measuring systems to measure a wide variety of Swiss Machined components.

For more than 20 years, Rowan Precision has been producing precision turned components at its production facility in Birmingham. Investment in the latest technology Swiss Machining centres allows for the manufacture of a wide range of components, from 0.5mm Ø through to 85mm Ø. Materials machined include aluminium alloys, stainless steels and plastics such as PTFE, resulting in an order book containing over 500 different component types.

To confirm that customers’ tight tolerances are adhered to, Rowan Precision has chosen two non-contact measuring systems from Vision Engineering. Kestrel is a 2-axis system, used for rapid, shop floor gauging applications. Hawk is an automatic 3-axis platform, used for more challenging measurement tasks where pre-programmed inspection routines can be run.

The products manufactured by Rowan Precision tend to be small, precision turned components with a number of complex internal and external features. For example, a typical application is the production of defence specification connectors, which must be made to extremely exacting requirements backed up by component traceability. These connectors have a number of broached key features, which ensure that the finished component will only locate into the correct socket. Accurate gauging of these broached features relative to a datum proved to be an extremely difficult and lengthy operation using alternative measuring techniques. When using a shadowgraph, the component had to be sectioned before a measurement was made. This not only destroys the part being measured, but is also extremely time consuming for the operator. The Vision Engineering equipment provides a true, optical view of the connector, allowing the operator to view both profiles and surface features. Using a combination of back lighting as well as incident illumination (lighting from above the part), even highly reflective, curved materials can be clearly viewed and measured.

Inspectors use the Kestrel as a shop floor measuring tool because it is simple to use, robust and provides fast results. The Kestrel is located alongside the CNC plant, allowing first off components to be taken directly from the machine for immediate inspection and measurement. Kestrel is straightforward to use, so operators and quality staff are comfortable making basic measurements.

The Hawk is a more capable piece of equipment and is located in the QC laboratory where it is used by specially trained Quality personnel. Hawk is a motorised 3-axis system with automatic Video Edge Detection (VED). This is run alongside a QC5000 PC package, which allows for measurement routines to be programmed and stored for future use. When frequent or multiple checks are needed on a particular component, the Hawk proves a useful tool for Rowan Precision as a previously configured program can be recalled and automatically run. All the Quality Engineer has to do is locate the component on the Hawk’s stage and start an inspect cycle. Once the routine is completed, a data report can be stored and printed, part of the data trail that is vital for quality systems and component traceability.

Chris Kent, a director of Rowan Precision explains why he chose the Vision Engineering equipment. “We wanted to find a measuring solution that would work for our entire range of production, from complex connectors through to stainless steel and plastic medical devices. Hawk and Kestrel offer us this flexibility and give us confidence in the accuracy and repeatability of our processes.”

Keeping Track of Quality

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Keeping Track of Quality

From its humble beginnings as a music carrier the Compact Disc (CD) or Digital Versatile Disc (DVD) is now entering its 3rd generation for the high definition market (HD DVD or Blu-ray). The one thing that needs to stay consistent is the high quality production of these polycarbonate replicas.

CD’s are a part of nearly everyone’s life, and they have become versatile enough for us to store data, copy data and for some, to use as a coaster… This is generally common knowledge, but how many of us are aware of how they are produced and how this can affect the overall quality of the disc and its output.

How they are made
CDs or any optical disc format are made from polycarbonate which has been injection moulded to reproduce the exact profile of the discs data. Before the molten granules of polymer are fed into an injection moulding machine from the hopper, the injection moulder is set with a nickel master called a Stamper. The nickel Stamper is an intrinsic part of the process, because if the stamper is anything less than perfect, the whole batch of CD’s (which could be thousands) could potentially be wasted.

With all the attention on the stamper preparation (due to the implications of any imperfections), the production of such an important part of the CD manufacturing process must produce a bead of sweat on the brow of the most experienced mastering engineer.

The Stamper

The Stamper is made of a disc that is punched from a nickel sheet 3.0mm thick. This procedure is implemented with precision because of the hardness and the thickness of the nickel. To ensure the stamper has been accurately punched it is essential that as part of the quality procedure, the stamper is measured using a non-contact method. This is because using a contact method like a sprung loaded bore micrometre will create denting in the punched ID and an oversize reading due to the relative softness of the nickel. This may also cause permanent damage to the hole geometry.

Sibert is a company specialising in supplying equipment to punch the nickel Stamper. After punching, Sibert measure them in 3-axes with a non-contact system from Vision Engineering. The discs are placed onto the glass stage with X-Y linear encoders with a resolution of 1μm and measured with specially modified graticules for repeatable results. The measuring accuracy for the nickel plates is ± 1.5μm. However, before measuring the disc, any protective coating must be removed and any dust or debris gently removed from the punched ID.

One of the clear advantages of using a manual non-contact method is how measurements can be taken by the human eye and therefore accounting for selective placement of the graticule. Automated processes may not take this into account and subsequently provide an inaccurate reading. The images below show how different the mono image can look when dust and debris are present on the profile edge.

Fig.1 (left) shows a clean and clear edge without dust and debris.

Fig.2 (right) shows an edge that is not very well defined due to the dust and debris.

In addition to this advantage using a non-contact method of measuring, other advantages using a non-contact optical method is when the punched radius is measured. Some automated machines focus on the radius rather than the bore (or punched entry point), hence this can sometimes give a oversize reading where the soft nickel has become slightly inverted during the punching process. The punch forms a curve in the nickel so objective placement of the cross hair graticule on the curve is necessary.

Steve Knight, Applications Manager at Sibert explains the importance or measuring the stamper and hole accurately.

“A four point measurement is optimum for accurate hole size, with the ‘unroundness’ reading also displayed. The cross hair should be placed carefully to avoid erroneous defects, which will affect the reading. It is equally as crucial to make sure the stamper is held flat onto a glass stage during measuring.”

The ID size can be calculated and displayed in three different ways including minimum circumscribed circle, maximum inscribed circle and the average hole size (gauss). The minimum circumscribed circle (taking any ‘unroundness’ into account) is the largest circle that can be inscribed over the maximum deviation point on the ID hole plot. This has no real use for a stamper and the ID measurement will always be larger.

The maximum inscribed circle is the maximum size perfect circle or shaft that will fit within the ID hole profile. In theory this should represent the stamper holder but in practice will produce an undersize reading.

Average hole size (Gauss). This is the average size between the two methods and they represent the optimum fit of the stamper onto the holder. Any small amount of irregularity in the bore will be adjusted as the stamper is fitted onto the holder, due to the softness of the nickel. ID measurements should also be verified on the other side of the stamper. The results should be within 2μm of each other.

To achieve a good quality, clean punched hole, the stamper hardness should be within 200 ± 10% HV0.3. The HV value is taken from the Vickers Pyramid, determined by the resistance of the material (in this case the nickel) to deform when an indenter is forced upon it. Stampers harder than this may have a ragged cut but stampers softer than this have an extensive punch entry radius.

Measuring the eccentricity ECC
Measuring the eccentricity (ECC) of the stamper and the stamper ID hole require high accuracy, this can be obtained by measuring them simultaneously so the ID size does not influence the ECC result.

The ID is measured first, followed by a media band. The distance between the centre points of the two circles is calculated as ECC (Total Indicator Reading TIR is twice ECC). When measuring for optimum ECC, the geometry of the punched hole also plays a part in the end result.

Quality and the future of the humble CD
Whether CD, DVD, HD or Blu-ray, the quality of the disc needs to be mass-produced to consistently high standards. This insight into the manufacture of optical discs can only tell us what we already know, the quality and performance you can expect to achieve from optical discs is extremely high. As the tolerance gets tighter and tighter and technology expands, we can only expect to find ourselves getting closer to the ‘real’ experience of either being at our favourite artists concert or sitting on the side lines of a film set.

Lynx captures Tiger

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Lynx captures Tiger

The Regional Agency of Environmental prevention in Emilia-Romagna, University of Ferrara (Biology department) and the Museum of Natural History in Parma have invested in 5 Lynx stereo zoom microscopes, to observe and count eggs from the Tiger Mosquito to forecast their arrival, understand and prevent their invasion into local communities.

The Regional Agency of Environmental Prevention in Emilia-Romagna (ARPA), Italy has invested in 5 Lynx Stereo Zoom Microscopes from Vision Engineering Ltd (Italia) for research into the Aedes Albopictus, Tiger Mosquito.

ARPA has invested in Lynx to check and count laths (narrow strip of straight-grained wood) and the Tiger Mosquito’s eggs. This is essential for understanding the mosquito and researching to meet the main objective which is to take control of the invasion by these ruthless insects in Northern Italy.

The Tiger Mosquito has historically only been prevalent in Asia but with factors such as global warming, they have invaded and thrived in other continents including both the Americas and Europe. It is thought that the invasion into the Americas and more specifically in Texas began in 1985 when a consignment of second hand tyres from Asia contained the insect/eggs and in two years the mosquito had spread from Texas through 17 states!!

Named the Tiger Mosquito because of it stripes, it can be up to 1cm in length and can lay anything between 100 and 300 eggs at one time. The female mosquito can frequent the lath to lay her eggs every couple of days resulting in an explosion of these insects.

With a preference for warm, damp conditions, the Tiger Mosquito inhabits reclaimed flood plains in Northern Italy where ARPA has placed several snares to encourage the Tiger Mosquito to lay their eggs. The lath snares are placed in small, dark waterways like reservoirs which naturally attract the insects to lay their eggs, ARPA can then collect the lath snares (weekly) and conduct their research.

Mosquito’s are renowned for carrying disease and one of the primary disease they carry is Chikungunya Fever, a haemorrhagic fevers (VHFs). First described in Tanzania in 1953, the fever is most likely to occur in young children from 5 to 9 years old, causing symptoms such as fever, crippling polyarticular arthritis, severe rash and sometimes conjunctivitis with bleeding of the skin and eyes. These diseases are one of the main reasons why the Tiger Mosquito’s need to be controlled where epidemics have been associated with poor control of mosquitoes.

Research by agencies such as ARPA, are key to understanding and eventually controlling the spread of these relentless insects. Initially, ARPA can forecast the influx of mosquitoes with their observations and counts of the eggs. However, ARPA activities cover all aspects of environmental control and additional custom-made activities on behalf of local clients, these activities include study & characteristics of ecosystems. ARPA has partnered up with The University of Ferrara (Biology department) and the Museum of Natural History in Parma, where they are striving to achieve an effective solution for the control of Tiger Mosquitoes.

Together with The University of Ferrara and the Museum of Natural History in Parma, ARPA have invested in the Lynx because the stereo microscope provides a very unique and patented Dynascope optical head. The Dynascope, ‘eyepieceless’ viewing head means technicians can observe and count the eggs with optimum comfort rather than being crouched over a traditional stereo microscope with a binocular head. Where technicians are using apparatus and instrumentation for hours, ergonomics is important not just because companies and organisations are investing in the health and safety of their staff, but because long periods of time spent in uncomfortable and positions means both accuracy and productivity is compromised.

The Lynx stereo zoom microscope provides technicians with up to x120 magnification with a fatigue free view. As well as the unique Dynascope viewing head, the Lynx is a modular system with versatile configurations and accessories. The bench stand seen in figure 3 provides a 14-point LED ringlight for cold white light (essential when observing life science subjects) in addition to substage illumination. Other configurations include different stand options, a variety of optical heads and accessories designed to enhance your viewing comfort, such a wedges to angle the head for maximum viewing performance. Digital image capture and cataloguing can be used with the stand for archiving; the oblique and direct viewer can provide views of the subject at 34° with a 360° rotation; and a variety of other accessories can enhance the versatility, allowing the system to be used for a variety of tasks including:

– Checking the morphology of cells
– Cell counting
– Measuring
– Observing
– Dissecting

With ARPA’s continuous investment in constantly updating instrumentation and development of new methods and technology, the agency for environmental protection can continue to support the local ecosystems with research and development in protecting the local environment from pests such as the Aedes Albopictus, Tiger Mosquito.

The Fine Art of Optical Inspection

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The Fine Art of Optical Inspection

 

Antique art restorer Lloyd Williams finds resolve in the new Mantis magnification stereo viewer from Vision Engineering, for his magnificent work restoring art and antiques using a wide variety of techniques and materials under magnification.

Lloyd Williams has over 35 years experience of restoration in a wide range of techniques, materials, periods and styles. From 17th century Mogul cabinets and art objects, French Empire presentation firearms, Chinese furniture, Spanish Colonial tortoiseshell and silver boxes, to European scientific instruments. Techniques include: stone, wood and iron carving; gold and silver damascene work; engraving and painting.

Lloyd utilises the Mantis for many tasks including working in gold and silver for example, an antique butt plate from a 17th century German wheel lock sporting gun has gold and silver foil applied to it using damascene technique requiring optimum clarity and accuracy. The gold and silver are applied after a series of intersecting parallel knife-cut lines have been made to allow the gold or silver foil to be interlaced, generally referred to as the damascene technique. After the surface has been cleared of remaining detail (if insufficient to include in the new work), hatching is applied to prepare for penetration of the foil.

Damascene technique is one of many processes that Lloyd uses to apply decorative designs to antiques. A priority when applying any technique under magnification is to establish a good working distance, especially when using tools to create cavities to inlay stones or jewels. Mantis provides a substantial working distance up to 96mm with the X4 objective lens and advantageous flexibility with a universal stand. The Universal stand can be bolted to a workbench quickly and easily using the ‘G’ clamp provided or simply bolted to the work surface.

Offering visually tangible benefits, the new Mantis is a dynamic and versatile tool for art restoration. With a large field of view and depth of field Lloyd can confidently pursue his activities under magnification with the superior stereo image delivering maximum depth and field of the subject. Mantis provides up to 34mm field of view of the subject with the X4 objective lens.

Mantis illuminates the subject with 24 LEDs, benefiting users such as Lloyd because the illumination remains cold unlike traditional lamps that generate heat when they are used for long periods. Needless to say, minimising effects such as these is crucial in art restoration when working with heat sensitive materials such as tortoiseshell.

Ergonomic considerations alone dictated that Mantis should function with an apparent distance to the image of a viewed object identical to that of the actual distance to the real object. As art restorers frequently alternate their views from the magnified object image to the actual object (especially when manipulating the part), this eliminates the need for the eyes to refocus each time ? a tangible advantage in reducing eyestrain and fatigue.

Lloyd explains “Without a doubt, Mantis has met with my expectations and has delivered an outstanding alternative to conventional magnification. The ergonomic advantages of the Mantis stereo viewer are unparalleled with any conventional microscope. I have been highly recommending it to other antique and art restorers in the field and will continue to do so.”

Oblique lens system with all-round view

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Oblique lens system with all-round view

The ABS electronic Meiningen GmbH Company in the Dreissigacker industrial estate of the theatre and culture town of Meiningen in southern Thuringia regards itself as a service provider for automation, component placement and controller solutions with a spectrum of performances ranging from customised printed circuit component placement to complete module development and fabrication.

The business enterprise has shown continuous growth since its foundation in 1998 by managing director Andreas Oertel. Two years later it was already necessary to purchase land on which building started in May of the following year and was completed by the end of the same year. As a result, on 2.1.2002 the company and its 18 employees moved into the new production and administration building commissioned with state-of-the-art technology in the Meiningen-Dreissigacker industrial estate, which covers 87.5 hectares and is thus the biggest in the southern Thuringia region. More than 70 companies from the processing industries, precision and special mechanical engineering, the producing sectors and the building trades as well as commerce and services have already established themselves here, and industrial sites are still available for occupation.

Today ABS electronic has already quintupled its staff to 65 employees, eight of them working in administration and the remaining 57 in production. The steady growth is based on consistent customer orientation, team spirit and the use of earnings for new investments to secure the technological head start. The characteristic features of the business are high quality and adherence to deadline dates, for which the eight Lynx stereomicroscopes in use in the vertical pillar and 34° rotation angled optics configuration are responsible, among other things. The company has also developed into a training establishment recognised and tested by the Chamber of Industry and Commerce.

Inspection and reworking

The Lynx stereomicroscope was developed using Vision Engineering’s patented Dynascope technology which provides the user with exceptionally good ergonomics because no restrictive eyepieces are used. All of the robust microscope’s functional elements are easy to use, without consequent loss of image quality. The eyepiece less lens system makes a decisive contribution to improved head position freedom and less eye tiredness. The latest developments in the optical design area ensure that the eyes and hands can work together in a natural way, which in turn leads to higher throughput, greater accuracy and fewer rejects. The zoom magnification range from x2.1 to x120 yields sharp images at long working distances and great depth of focus. The modular design enables accessories and options to be interchanged quickly. For example it can be converted in no time from the instrument configuration for reworking (small magnification and long working distance) to inspection configuration (high magnification, optimum image area, documentation option).

The Dynascope technology enlarges the exit aperture and thus the beam path to achieve improved freedom of movement for the head and neck structures. This also results in the unrestricted ability to wear vision aids, in addition to an ergonomic body posture in front of the system. Moreover the system provides three-dimensional viewing, whereby the apparent distance from the image of the object being viewed corresponds to the distance from the real object. The operator has no need to refocus his eyes constantly when he/she looks away from the microscope and directly at the object.

The pillar stand variant as used at ABS electronic ensures greater flexibility and user friendliness. For example the pillar option comprises an adjustable, swivelling pillar stand for direct attachment to the operator’s working surface, or alternatively with a coated baseplate for easy transport. The crank handle option enables easy vertical adjustment when frequent changes in working distances are necessary. The product range also includes a robust, focusable table-top tripod with specimen holder and transmission illumination together with options for a sliding stage or measuring stage.

The “34° Rotation” angled lens system allows the user to view an object from an angle of 34° to the vertical axis. A rotation of 360° around the object being observed enables an improved stereoscopic view of three-dimensional objects, for example soldered joints on PCBs, drilled holes, cut edges and thread shapes. The lens system can be pivoted out for a vertical view. The accessory that the Thuringian service provider also uses is available as a manual and a motorised version.

Models

Another model is the “Rigid 25°” angled lens system that enables the user to observe objects being examined from a fixed angle of 25°, for example during printed circuit board inspection. On the other hand an ergotube allows a variable setting of the direct-view/inclination angle. Digital, video and 35-mm roll film camera adapters are used to attach the relevant cameras, and there are modular multi-media solutions for image archiving, acquisition, processing, analysis and documentation. When attached to a camera, the images are stored at high resolution in the camera and afterwards transferred to a PC where they are archived, inserted into a QA report or sent by E-mail. Storage takes place in JPEG format and is usable by popular programs without conversion. A 2-station multiplier enables the stereo zoom range to be increased by a factor of x1.5 or x2 without impairing the working distance. By using measuring and comparison graticules the operator can measure objects and compare them by means of a scale. Standard graticules such as a hairline cross or measuring scale are available, and customer-specific graticules can be supplied on request.

  • Even spectacle wearers can test effortlessly
  • Testing workplaces with stereomicroscopes in fabrication
  • A Meiningen company

ABS electronic also made an early start on the changeover to lead-free. Thus the company’s main focus is on the placement of components on printed circuit boards, in addition to the development and manufacture of industrial controllers. For example there has been investment in a new wave soldering machine and an additional component placement machine as well as an automatic template printer and various rework stations.

The transport boxes for the modules that are delivered are also used by the customer for his own production processes, which means a saving of time and cost. Fabrication ranges from a single item to a medium-sized mass production run of 20,000 items. The automatic component insertion equipments process the whole spectrum of components from, among others, 0201 up to QFP, BGA, uBGA, CBG, CSP or Flip Chip. The work in all the fabrication areas is carried out according to the ESD (Electrostatic Discharge) Guidelines. Great importance is placed on the quality of the individual printed circuit boards fitted with components as specified by the customer. Customers at home and abroad value above all the high quality of the products in addition to the quickest possible processing of orders. Therefore the modules are inspected using a modern AOI (Automated Optical Inspection) technique and tested before they are delivered. The company has been certified since 2003 in accordance with DIN EN ISO 9001:2000. This also includes company-specific vocational training that is implemented in co-operation with other high-tech businesses and institutions of higher education. Effective environmental protection is an integral part of the corporate philosophy. In addition to fulfilling the EU’s RoHS Directive (Restrictions on the use of Hazardous Substances in electronic equipment), which specifies lead-free production when processing printed circuit boards, the company guarantees the far-reaching conservation of environmental resources. For example the buildings are heated in winter and cooled in summer by heat pumps.

www.visioneng.de & www.abselectronic.de

Lynx boldly goes where no-one has gone before

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Lynx boldly goes where no-one has gone before

Man’s ongoing quest to understand the origins of the universe is currently getting a helping hand from an unlikely source: Woking-based optical inspection innovator, Vision Engineering. The Max Planck Institute for Chemistry, based in Mainz, Germany, has recently purchased several of Vision’s advanced Lynx™ inspection systems for use in its Cosmochemistry and Geochemistry departments, from where the study of solar system materials takes place.

The user-friendly Lynx utilises a viewer assembly rather than eyepieces to deliver a pin sharp stereo image and permit a greater degree of body position freedom for the operator. It is currently being employed by the Institute to help study isotopic compositions of various compounds found in meteorites, and will also soon be used to study lunar samples brought back from the moon landings, and interplanetary dust particles. The samples include materials that, in all likelihood, come from the planet Mars, as well as tiny particles within the most unprocessed meteorites that predate the Earth’s solar system, known as ‘stardust’.

“The Lynx is used as part of a technique called Thermal Ionisation Mass Spectrometry, or TIMS”, explains Uli Ott, Senior Scientist at the Max Planck Cosmochemistry department. “This is used to date samples and to identify isotopic abundance anomalies, which provide important information on the stellar sources of the chemical elements.” TIMS involves dissolving a given sample in acids and separating the relevant element to be studied using ion exchange columns. A microlitre of the solution is then deposited onto a small filament ribbon, typically just a millimetre wide and a few centimetres long, and made of tantalum, tungsten or rhenium. Special chemicals are then added to improve the yield and dry the ribbon before it is loaded into a mass spectrometer.

“In order to get the best results, the deposition process is vital”, states Ott. “When depositing such a small amount of liquid onto such a small area, and trying to get that liquid in a central position, a clear view of the process is imperative. That is where the Lynx comes into its own.”

The ergonomic Lynx delivers a high resolution image to the eyepieceless stereo viewer using Vision’s patented dynascopic disk. The unique infinity-corrected afocal design makes the apparent distance to the viewed object image identical to that of the real object, eliminating re-focussing of the operator’s eye to reduce the likelihood of fatigue. Lynx also benefits from a large field of view, magnification of up to x160 and a superior camera offtake. The large working distance between the Lynx objective lens and the filament ribbon makes manipulation easy and improves hand-to-eye co-ordination, as Ott explains: “With such a good view, the deposition of the solution onto the filament ribbon is at an optimum. This provides the highest possible signals in the mass spectrometer and, therefore, the highest accuracy in isotopic ratios.”

“Historically we have used a camera and video screen, or standard microscopes”, says Ott. “But the Lynx allows relaxed and easy 3-dimensional viewing that not only aids the operator, but also enhances the end results we get from the spectrometer tests. It is uniquely suited to the application in the Cosmochemistry department and is a great addition to our facility and capabilities.”

Non-contact optical (visual) testing of electronic components

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Non-contact optical (visual) testing of electronic components

Non-contact optical (visual) testing of electronic components

Optical (visual) tests on small, complex components impose great demands on the tester. When the work is also carried out in a three-shift operating system, as happens at the Paragon AG Company in Suhl, Germany, a manufacturer of electronic components, the testing instruments must also satisfy special requirements regarding their ergonomic handling in addition to the technological demands. This is why eyepieceless viewing systems are used for visual testing by microscopy.

The high-tech company Paragon, founded in 1988, develops and manufactures system solutions for automotives, electronic solutions and buildings engineering through the symbiosis of electronics, mechanical engineering and software. The German sites are in Suhl, Heiden¬heim, St. Georgen and Cadolzburg, and the head office is in Delbruck. The Suhl factory, which is the subject of the present report, focuses on products for in-car electronics. This starts with communications technology and goes all the way to the air quality sensors for air-conditioning systems. Paragon is, among other things, world market leader in the manufacture of air quality sensors for the automobile industry.

Thomas Gunther from Paragon’s production management explains: “We manufacture here on automatic fabrication lines on which Vision Engineering’s instruments are also used for the visual monitoring. Firstly these optical inspection systems are used to check soldered joints in the SMD (surface-mounted device) area, and secondly they are also used to check modules and to repair them in the context of trouble-shooting. In addition they are also employed for the quality control of the mechanical connections in the context of the qualification of modules.”

Thus at Paragon the whole operation is a thorough visual checking. However, the test instruments also play their part in new developments. For example they are also used for process qualification steps and technological new starts, i.e. when a master component placement is made for a particular product, a 100% visual check is then carried out under the microscopic testing system.

About 15 optical inspection systems for visual testing are in use in the production facility at Paragon. The stations in the photo are also used for small repairs on the components.

Continuous use and ergonomics

The optical inspection systems that are used have been marketed in Germany by the English company Vision Engineering for more than 20 years and they differ significantly from classical microscopes. Marketing representative Walter Dirschl, who is responsible for supporting Paragon, explains that: “We regard ourselves as more than manufacturers of work equipments, i.e. the difference compared to classical microscopes lies in that fact that staff can work on these systems for prolonged periods, e.g. an entire shift as at Paragon. The user adopts an unconstrained body attitude and sitting position during the inspection work, as a result of which he/she does not suffer any neck and back problems and over-strained eyes or headaches.”Moreover, various lens systems were developed for electronics applications like those here in Suhl. For example a soldered joint can be viewed not only from above but all round from all sides. For Thomas Günther, the ability to inspect soldered joints in three dimensions and from all sides represents a great benefit. Technologically this is the decisive speciality of Vision Engineering’s test systems. In principle the microscopes are constructed like stereo microscopes. The only difference is that instead of the eyepieces, Vision Engineering has developed a “Projection Head”. Two beam paths are brought into this projection head. The latter then contains a disk on which about 3.5 to 4 million lenses are positioned by photo technology. Each of these lenses individually splits up the beam path and feeds it into the projection lens so it can be seen by the observer. This creates an optical image at a point where the microscopy can be carried out at a large working distance from the image. This is also a decisive advantage for spectacle wearers, because they can continue to wear them during the entire inspection work. For the same reason the instruments do not need any refraction adaptation either. This technology also completely eliminates the danger of infections caused by direct eye contact with the eyepiece by different persons.

Renishaw Relies on Mantis Macro Stereo Viewers

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Renishaw Relies on Mantis Macro Stereo Viewers

Renishaw plc employs the use of Vision Engineering’s Mantis® Macro and Mantis® Elite stereo viewers to inspect dental frameworks for finished quality, precision and fit.

Renishaw has been manufacturing innovative measuring solutions for over 33 years and has recently identified the need within dentistry for a refined and accurate process for crown and bridge framework manufacture. In doing this, Renishaw has designed and developed incise™ ? a revolutionary dental CAD/CAM system that focuses on accuracy at every stage of the process, beginning with the first impression taken by the dentist. To support its own digital checking procedures, Renishaw uses Vision Engineering’s range of Mantis® stereo viewers to assist with all aspects of the process, from quality assessment of machine parts to visual inspection of the finished frameworks.

Renishaw’s Dental Products Division has taken a radical review of the conventional way dental restorations are manufactured. From this, the incise™ process was born, providing an innovative solution to the manufacture of all-ceramic parts. Traditionally, the dental industry has used metal in the production of crown and bridge frameworks. Occasionally metal crowns can cause reactions resulting in gum recession and exposure of unattractive metal collars that are prone to decay collection and staining.

Renishaw’s incise™ process uses a strong, hard ceramic material called zirconia. The material is biocompatible so is extremely friendly to oral tissues encouraging better oral health. The metal-free core gives the benefit of a more natural, translucent appearance.

The accuracy of marginal fit that the incise™ process can achieve means increased resistance to decay and staining, resulting in a longer lasting restoration. To optimise the accuracy of the whole process from start to finish, Renishaw has been working closely with dentists and dental technicians to improve the overall quality of the finished restorations. Renishaw provides a set of guidelines to help eliminate errors at each stage of the impression and die process, ensuring the precision of the finished reconstruction.

Process overview

Initially, the patient has a consultation where the dentist provides a prescription for reconstruction to restore ideal jaw function or to improve aesthetics. The teeth are then prepared and, using Renishaw’s proven techniques and materials, the dentist takes impressions of the teeth and surrounding tissues. The patient is fitted with temporary restorations to protect the prepared areas and the impressions are sent to the dental laboratory, together with any other relevant information on the patient’s clinical situation. Even at this early stage, it is vital that the impressions are free of defects. From the impressions, stone models are made of the upper and lower jaws which are then articulated together to represent the patient’s bite. The model of interest is sectioned and the prepared areas are removed, trimmed and measured using the incise™ scanning machine, which generates a three-dimensional representation of the stone model. The machine scans the model using a contact scanning probe, digitising the complex form of the preparation replica. Data from the scan is then sent electronically to Renishaw’s milling centre in Gloucestershire where the zirconia framework is manufactured.

Renishaw incise™ frameworks are supplied with a certificate of conformance, showing an analysis of the framework fit to the original stone model. The zirconia framework and the certificate are packaged and sent back to the dental laboratory for porcelain build-up. The finished restoration is returned to the dentist along with the certificate. The dentist will then complete the process by removing the temporary and fitting the incise™ restoration, checking the colour match and contacts with surrounding teeth and the essential marginal fit. When the dentist and patient are happy, the crown or bridge is permanently cemented in place.

When the project was in its infancy, Renishaw was using several methods of inspection including loupes. Although this method gave adequate magnification, the practicalities of inspecting through such equipment was not ideal, especially for long term use. Bryan Austin, Director & General Manager of the Dental Products Division at Renishaw visited a number of dental laboratories during the early stages of the project and immediately identified how they were using the ergonomic Mantis stereo viewer from Vision Engineering. Bryan Austin explains, “With the hours that are spent by production staff peering into eyepieces of microscopes or loupes, it made sense to invest in equipment that provided maximum comfort as well as optimum clarity. The Mantis delivered everything we needed to successfully carry out our visual inspection process. With the certificate of conformance that we are providing to our customers, it is imperative that we produce crowns and bridges that are a perfect fit. We use the Mantis to inspect the machined parts giving us total confidence that our incise™ scanning machine is producing accurate dimensions, resulting in prosthodontic parts that are a precise representation of the patient’s teeth”. Bryan goes on to explain how having an inspection station changed the whole mindset of the inspector. “After we designed the inspection station using the Mantis, we found that when the inspectors physically took the framework over to the system and initiated the inspection procedure, it changed their whole psyche”.

The upper image shows four anterior porcelain jacket crowns, three of which were 30 years old. It is obvious where the poor fit of the crowns has caused the gums to recede, exposing dark margins & collecting decay. The second image shows the same patient with newly fitted incise™ crowns. The gums look extremely healthy and the aesthetic result is superb.

Before the ceramic frameworks are dispatched back to the laboratory, they are inspected using the Mantis range of stereo systems from Vision Engineering. Renishaw has invested in a Mantis Elite stereo viewer and a number of Mantis Macro viewers with straight through viewing. After the parts have been machined, they undergo a final inspection. The cold bright white LED light of the Mantis range provides adequate illumination to inspect the uniformity of the parts.

The incise™ scanning system is validated to BS EN ISO10360 part 4 (an international standard relating to the accuracy of contact scanning systems) and all restorations are produced under a BS EN ISO13485 quality system.

With Renishaw introducing innovative measurement solutions and proven technology like the incise™ system into the medical devices industry, including dental technology, the benchmark has now been set for high precision and quality.