| 1. |
- Dickerhof, M., et al.
(författare)
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Towards an european approach for characterisation of multimaterial micromanufacturing process capabilities
- 2012
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Ingår i: Precision Assembly Technologies And Systems. - Berlin, Heidelberg : Springer. - 9783642281624 ; , s. 200-209
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Konferensbidrag (refereegranskat)abstract
- The paper describes a comprehensive approach for the modelling and description of technologies available within a European Research Infrastructure consisting of distributed research infrastructures all over Europe. The resulting knowledge management system integrates the partial approaches of several European research activities in this area to a comprehensive description format for technical capabilities as well as maturity and economic aspects.
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| 2. |
- Mattsson, Lars, 1950-, et al.
(författare)
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How reliable are surface roughness measurements of micro-features? : Experiences of a Round Robin test within nine 4M laboratories
- 2008
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Ingår i: 4M 2008. - Dunbeath : Whittles Publishing. - 9781904445760 ; , s. 139-142
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Konferensbidrag (refereegranskat)abstract
- Surface roughness of tiny micro machined features is not easy to verify. The statistical variation of the surface itself can be the limiting factor that hampers tolerance verification. In this paper we have studied this effect and we also test the performance of 10 different surface profilers over a very well specified surface area. For this area 6 profilers yielded the same result within a standard deviation window of ±6%. For other areas, on top of narrow bars and in narrow and deep channels, a much larger spread in the Round Robin results were found.
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| 3. |
- Nilsson, Bruno, et al.
(författare)
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Fast four-channel fibre-optic displacement sensor for measuring impact waves at low cost
- 2006
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Ingår i: Measurement science and technology. - 0957-0233 .- 1361-6501. ; 17:5, s. 1162-1166
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a fast four-channel fibre-optic sensor for measuring dynamic surface displacements caused by shock waves. Light from an LED emitter is sent through a plastic fibre and reflected from the surface back into the fibre. The intensity of the reflected light gives the distance to the surface unambigously. Based on simple principles and utilizing inexpensive components, micrometre and microsecond resolution is achieved at lower cost and with easier usage than for interferometric methods and with better reliability than an accelerometer. The sensor is comparatively easy to set up. It is battery operated for reduced sensitivity to electromagnetic interference. The design of the fibre probe facilitates access in narrow and hostile environments.
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| 4. |
- Nilsson, Bruno, et al.
(författare)
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Fast, low-cost fiber-optic displacement sensor
- 2005
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Ingår i: 17th International Conference on Optical Fibre Sensors, Pts 1 and 2. - BELLINGHAM : SPIE-INT SOC OPTICAL ENGINEERING. - 0819458554 ; , s. 783-786
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Konferensbidrag (refereegranskat)abstract
- We have developed a fiber-optic sensor for measuring dynamic surface displacements caused by shock waves. Light from a LED emitter is sent through a plastic fiber and reflected from the surface back into the fiber. The intensity of the reflected light gives the distance to the surface. Based on simple principles and utilizing inexpensive components, micrometer and microsecond resolution is achieved at lower cost and easier usage than for interferometric methods and with better reliability than an accelerometer. The sensor is comparatively easy to set up. It is battery operated for reduced sensitivity of electromagnetic interference. The design of the fiber probe facilitates access in narrow and hostile environments.
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| 5. |
- Temun, Attila, et al.
(författare)
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Assessment of digital cameras for micro-structural sensing of low contrast surface features
- 2005
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Ingår i: Proceedings of the First International Conference on Multi-Material Micro Manufacture 2005, Karlsruhe, DE. - Amsterdam : Elsevier. - 0080448798 ; , s. 253-257
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Konferensbidrag (refereegranskat)abstract
- Evaluation of three digital cameras are presented focusing on their capabilities and applicability in the detection of low-contrast surface features on the micrometer level. The key to a successful identification of surface flaws on microstructured surfaces, such as silicon wafers is the ability to determine minor deviations in the reflectance of an object surface. Micro-topography of a surface, surface structure and surface roughness has a strong influence on the amount and direction of scattered light. Different portions of the surrounding illumination are reflected on different parts of an uneven surface, hence the resulting contrast-variation on the illuminated surface has a strong correlation to the surface structure itself. In our work we discuss the possibilities of using either of the investigated cameras for the automated visual inspection of micro-structured surfaces. The cameras - two of them equipped with CCD and one with CMOS image sensors - are studied in an environment which is similar to standard surface appearance measurements, involving human observers. The specimens, featuring different surface structures are imaged in a well-controlled environment under varying illumination conditions. Experimental results of spatial resolution and contrast sensitivity are presented.
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| 6. |
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| 7. |
- Temun, Attila, et al.
(författare)
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Localizing micro-defects on rough metal surfaces
- 2006
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Ingår i: Proceeding of the 2nd International Conference on Multi-Material Micro Manufacture 2006, Grenoble, FR. - Amsterdam : Elsevier. - 9780080452630 ; , s. 169-172
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Konferensbidrag (refereegranskat)abstract
- In this paper we present a study of reflectance measurements to a direct metrological problem. Our aim is to estimate progressive surface wear by detecting minute defect development in surface microtopography on Ra 0.7 μm rough stainless steel surfaces subject to mechanical wear from hard particle deposits on a metal bar. The investigation was carried out by using a standard CMOS digital camera with a macro objective. It demonstrates how surface scattering measurements can provide a viable alternative in circumstances where traditional roughness measurement techniques fail to deliver the expected results and, due to certain restraints, laboratory-type surface measurements are not applicable either. Our work is based upon measuring variations in the amount and direction of scattered light, reflected from the inspected surfaces, featuring microirregularities. We will show that it is possible to identify the extent of surface flaws by statistically evaluating the recorded brightness information. The developments in this paper can provide basis for a future quality control system devoted to on-line surface measurements of micro components.
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| 8. |
- Tilert, Dan, et al.
(författare)
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Measurement of Explosively Induced Movement and Spalling of Granite Model Blocks
- 2007
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Ingår i: International Journal of Impact Engineering. - : Elsevier BV. - 0734-743X .- 1879-3509. ; 34:12, s. 1936-1952
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Tidskriftsartikel (refereegranskat)abstract
- Charges of high explosives have been buried (countersunk) in granite blocks and detonated. This article describes the measurement and evaluation of the shock wave propagating through the granite blocks. It also demonstrates how the shock wave data can be used to improve computer simulations of granite's behaviour. The overall goal has been to investigate how granite withstands penetrating weapons, that first penetrate the ground and then detonates within the created cavity. Several variables have been investigated. It is shown that water content of the granite can increase the shock wave amplitude with up to a factor 2, and a crack in the granite often attenuates the shock wave amplitude with a factor 4 or more. Also, the granite block thickness needed to prevent internal crack formation has been investigated.
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