33 Original Scientific Paper Kapłonek, W., Kukiełka, K., Kukiełka, L., Nadolny, K., Hloch, S. CLSM-BASED MEASUREMENTS OF THE SURFACES OF THE EXTERNAL ROUND THREADS ROLLED ON COLD Received: 16 March 2014 / Accepted: 14 April 2014 Abstract: In recent years, a rapid development in optical metrology has been observed. In many applications, optical measurement systems are very broadly utilized due to their unique properties. In this work the Authors analysed the possibility of using a new advanced measurement technique based on confocal laser scanning microscopy, for the purposes of garnering precise measurements of the surface of external cold rolled round threads. During experimental tests The 3D laser microscope LEXT OLS4000, produced by Olympus, and equipped with OLS4000 2.1 dedicated software, was used. The test results obtained enabled a proper analysis of the important features of the assessed surface, particularly in terms of determining the correctness of the performed thread rolling process. Key words: Confocal laser scanning microscopy, 3D measurements, image analysis, cold rolling thread process CLSM- na bazi merenja spoljašnje površine hladno valjanih navoja. U poslednjih nekoliko godina primećen je brz razvoj u optičkoj metrologiji. U mnogim primerima, optički sistemi merenja se veoma široko koriste zbog svoje jedinstvenosti. U ovom radu autori analiziraju mogućnosti korišćenja nove napredne tehnike merenja na osnovu konfokalne lasersko skenirane mikroskopije, za potrebe preciznog merenja spoljne površine kod hladno valjanih navoja. Tokom eksperimentalnih testova korišćen je 3D laserski mikroskop LEKST OLS4000, proizvođača Olimpus, podržan sa namenskim softverom OLS4000 2,1. Rezultati testa dobijeni omogućuju pravilnu analizu značajnih karakteristika procesirane površine, naročito u pogledu utvrđivanja ispravnosti navoja nakon procesa valjanja. Ključne reči: Konfokalno lasersko skenirana mikroskopija, 3D merenje, analiza slika proces hladnog valjanja navoja 1. INTRODUCTION In the last few years there has been a large increase of interest in the capabilities offered by modern optical metrology [1] within the scientific and engineering community. It's hard to imagine scientific research in areas such as mechanics [2], materials science [3], microelectronics [4] or the broader activities related to quality control [5] carried out in the automotive, aerospace and machine industries, without the use of modern measurement systems based on optical techniques. The rapid and dynamic progress in developing the next generation of these systems has also made it possible to extend the scope of the areas in which such systems may potentially be applied, with a particular focus on those areas in which no solutions had yet been found [6]. Optical metrology utilizes a variety of such measurement techniques. Some of the most important that have rapidly developed in recent years are: − interference microscopy, using monochromatic laser radiation (from visible range and IR) or white light for very precise 3D surface measurements (WLI-White-Light Interferometry) [7]), − confocal laser scanning microscopy, using laser radiation for imaging and precise 3D surface measurements [8], − optical profilometry, using a chromatic aberration phenomenon for precise 3D surface measurements and analysis [9], − digital/opto-digital microscopy, using LED (Light- Emitting Diode) or halogen light for the rapid imaging and 2D/3D surface measurements required within many laboratory/industrial applications [10]. Among the above mentioned optical techniques, a special role especially in the measurement and analysis of technical surfaces, is played by the new advanced variety of confocal microscopy, called confocal laser scanning microscopy (CLSM) [11]. This method, characterized by a high accuracy and repeatability of measurements, was adapted from the biological/ medical sciences to the field of technical sciences and industry. In this work, the use of CLSM for precise measurement of the surface of cold rolled round threads was proposed. Brief characteristics of this method, taking into account the genesis of its development as well as the principles of operation of instruments based on it (Section 2), were also described. In the following part of the work (Section 3), was presented an example of the use of just such an instrument - the 3D laser microscope LEXT OLS4000 produced by Olympus - used in the recording of precision surface measurements of round threads. A description of the methodology and a review of selected results obtained during the tests are given in the final part of the work (Section 4). 2. CHARACERISTICS OF THE CLSM TECHNIQUE 2.1. The genesis of the CLSM technique Confocal microscopy is a technique originally developed in the mid 1950’s in the United States by