Length Measurements are included in countless ways throughout our daily lives, and there is a well-documented need for geometric measurements throughout the modern world. Industry and especially high technology is dependent on accurate length measurements – from the thread of a nut to precision-machined parts in a marine engine and down to the tiny structures on microchips in for example hearing aids and computers. Almost all material products require an accurate international scale for length and geometric shape in order to be specified, manufactured or traded.
Denmark has designated two metrology institutes within “length”.
Danish Fundamental Metrology A/S
DFM is designated in the subfields Basic length measurements, Dimensional metrology, and Micro/Nano.
DFM maintains primary length standards in the form of a frequency stabilized lasers referenced to molecular absorption lines. The lasers have a very well-defined wavelength, which ensures traceability in interferometric length measurements. DFM offers interferometric calibration of gauge blocks of the highest accuracy class (reference standards) with lengths from 0.5 mm to 100 mm. Furthermore, DFM offers calibration of distance measurement instruments and linear actuators by use of laser interferometry.
DFM’s activities within dimensional metrology includes calibration of roughness measurement instruments, roughness standards and hole plates. These activities were transferred from DTU Mechanical Engineering (CGM) to DFM on 1 January 2016.
The micro- and nanoscale area covers a wide range of geometrical measurements in a range from approximately one nanometre to several hundred micrometers, which have in common that they are measured by special instruments and methods. Examples include calibration of reference gratings in terms of grating periods and step heights using atomic force microscopy, optical microscopy or so-called scatterometry. In scatterometry the dimensions of surface structures are determined indirectly from measurements on light scattered of the surface.
For further information, see www.dfm.dk
Danish Technological Institute – Metrology & Quality Assurance
DTI is designated in the subfield Dimensional metrology.
DTI offers calibration within length and form, such as calibration of gauge blocks, measuring tapes, cylinder and spheres. DTI also offers calibration of handheld measuring instruments, such as dial indicators, micrometers and calipers, as well as external calibration of profile projectors and microscopes.
DTI’s activities within dimensional metrology also includes measurements using tactile and optical coordinate measuring machines (CMMs, where the optical CMM measurements are accredited), as well as CT (Computed Tomography) Scanning. CT Scanning makes it possible to perform dimensional measurements of both outer and inner structures without cutting, or in other ways destroying, the sample.
For further information, follow the link.
Danish Fundamental Metrology
DK-2800 Kongens Lyngby
+45 45 25 5876
Niels Thestrup Jensen
Danish Technological Institute
Metrology & Quality Assurance
+45 7220 2956