Dynamic Length Metrology (DLM) for measurements with sub-micrometre uncertainty in a production environment

Leonardo De Chiffre, Hans Nørgaard Hansen, Jesper Henri Hattel, Daniel González Madruga, Giuseppe Dalla Costa, Mads Rostgaard Sonne, Ali Mohammadi

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review


Conventional length metrology for traceable accurate measurements requires costly temperature controlled facilities, long waiting time for part acclimatisation, and separate part material characterisation. This work describes a method called Dynamic Length Metrology (DLM) developed to achieve sub-micrometre accuracy on metal parts, or micrometre accuracy on polymer parts, directly in a production environment. The method consists in the simultaneous measurement of all quantities affecting dimensions of a part over time (dynamically), involving a number of sensors and reference artefacts, followed by mathematical or numerical modelling of the thermo-mechanical effects. It is hereby possible concurrently to predict condition-specific material properties as well as part dimensions at any point, time, temperature, humidity, etc. Knowing all systematic errors and influencing factors, and their combined effect, on a given length, it is possible to calculate the corrected length at 20°C, zero measuring force, etc. An estimation of the measurement uncertainty U can be obtained following the guidelines of the GUM, dimensional values and their uncertainties being the final result of the analysis. Preliminary investigations have indicated that the approach is viable, either using analytical modelling or FEM. An expanded uncertainty (k=2) lower than 0.4 μm was achieved using a steel gauge block as workpiece.
Original languageEnglish
Title of host publicationProceedings of euspen’s 16th International Conference & Exhibition
Number of pages2
Publication date2016
Publication statusPublished - 2016
Eventeuspen’s 16th International Conference & Exhibition - East Midlands Conference Centre, Nottingham, United Kingdom
Duration: 30 May 20163 Jun 2016


Conferenceeuspen’s 16th International Conference & Exhibition
LocationEast Midlands Conference Centre
Country/TerritoryUnited Kingdom


  • Metrology
  • Low uncertainty
  • Production environment


Dive into the research topics of 'Dynamic Length Metrology (DLM) for measurements with sub-micrometre uncertainty in a production environment'. Together they form a unique fingerprint.

Cite this