Time filter

Source Type

Leach R.,National Physical Laboratory United Kingdom | Haitjema H.,Mitutoyo Research Center Europe
Measurement Science and Technology | Year: 2010

In this review we will discuss many of the problems that are encountered when designing and carrying out comparisons of surface texture measuring instruments. Previous comparisons are discussed to highlight some of the key issues. The limitations of stylus and optical instruments are identified with a focus on the spatial bandwidths in which they operate. Guidance is given on how to design comparisons to avoid variations in the results that are due to the operating principles and bandwidth limitations of the instruments involved. Methods for matching the bandwidths of different instruments are presented and some examples are given that highlight potential problems. The software aspects of instrument comparisons are also discussed. Finally, some advice is given on how to compare profile and areal surface texture measurements. © 2010 IOP Publishing Ltd. Source

Leach R.K.,University of Nottingham | Giusca C.L.,National Physical Laboratory United Kingdom | Haitjema H.,Mitutoyo Research Center Europe | Evans C.,University of North Carolina at Charlotte | Jiang X.,University of Huddersfield
CIRP Annals - Manufacturing Technology | Year: 2015

In this paper, the calibration and verification infrastructure to support areal surface texture measurement and characterisation will be reviewed. A short historical overview of the subject will be given, along with a discussion of the most common instruments and directions of current international standards. Traceability and uncertainty will be discussed, followed by a presentation of the latest developments in software and material measurement standards. The concept and current infrastructure for determining the metrological characteristics of instruments will be highlighted and future research requirements will be presented. © 2015 CIRP. Source

Chandra A.,Iowa State University | Anderson G.,Iowa State University | Melkote S.,Georgia Institute of Technology | Gao W.,Tohoku University | And 2 more authors.
CIRP Annals - Manufacturing Technology | Year: 2014

Solar cells gained significant interest recently due to the rapid increase in fossil fuel costs and renewed attention to sustainability. The effectiveness of a solar cell in energy harvesting hinges on three key characteristics: efficiency of energy conversion, reliability and life expectancy, and cost. All three attributes are critically influenced by surface and interface properties inherent in the design and manufacture of these devices. This paper starts with an exposition of solar cell manufacturing, followed by discussion of efficiency enhancement, reliability issues, and cost and energy footprint reduction. The role of surface and interface modifications in realizing such improvements is assessed. © 2014 CIRP. Source

Haitjema H.,Mitutoyo Research Center Europe
CIRP Annals - Manufacturing Technology | Year: 2015

Roundness measuring instruments exhibit roundness deviation of the spindle in the 20-30 nm range, and are specified as such. This requires test methods that deliver uncertainties within this range. In order to be feasible such a method must be carried out with a limited amount of measurements within a limited time. In this paper an analysis of the multi-step method for roundness calibration is presented, that analyses the method in terms of its Fourier components and its calculation. From this, an alternative calculation is derived that is as complete and accurate, but requires less measurements to be taken and achieves a higher level of completeness in error separation. Measurements are presented that illustrate the validity of the method and give an estimate of the lower limit of uncertainty that can be achieved, in this case 4 nm. © 2015 CIRP. Source

Haitjema H.,Mitutoyo Research Center Europe
Surface Topography: Metrology and Properties | Year: 2015

The 2.5-dimensional (2.5D) roughness parameters were standardized in 2012. With their increasing use in science and industry, the request for traceability and uncertainty evaluation for these parameters follows logically. This paper gives an overview of the problems and possibilities that appear when uncertainties have to be associated with values that are derived from a measured surface topography, suchasthe Ra-value of a periodic specimen, the RSm value of a type-D standard, and the Sa-value of a single cut off length of a type D standard. It is shown that straight forward implementation of the methods described in the 'Guide to the Expression of Uncertainty in Measurement' (GUM) leads to impossible and impracticable equations because of the correlations between some millions of measurement points. A practical solution is found by considering the main aspects of uncertainty, as these are given in the recent ISO 25178 standards series, and applying these to a measured surface topography as a whole. © 2015 IOP Publishing Ltd. Source

Discover hidden collaborations