LFSB Surface Roughness Standards (1985 and 2010)

(on loan from the University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Laboratory for Precise Length Measurement)

 

Surface roughness standards are used to calibrate instruments that measure surface texture — a property crucial for friction, wear, lubrication, and corrosion resistance.

In 1985, at the Laboratory for Precise Length Measurement of the Faculty of Mechanical Engineering and Naval Architecture in Zagreb, Prof. Sanjin Mahović, PhD, developed the first Croatian roughness standards, known as LFSB standards. They were made of monocrystalline silicon with measuring structures formed in a layer of silicon dioxide, and parts of the surface were gold-plated to enable interferometric measurements. This design made it possible to create exceptionally uniform structures at the nanometre and micrometre scale — something that could not be achieved at the time with steel or glass.

 

Their metrological excellence was confirmed by the national metrology institutes of Germany (PTB) and Italy (INRIM), as well as by the laboratory of the renowned UK instrumentation manufacturer Taylor-Hobson. Thanks to their reliability and innovative design, LFSB standards were purchased by metrology organisations in Austria, Italy, Slovenia, the Netherlands, Serbia, Bosnia and Herzegovina, and North Macedonia.

In 2010, in collaboration with the Ruđer Bošković Institute and the company MikroMasch Trading OU, new LFSB nano-standards were developed. They were designed to support a wide range of measurement techniques used in modern nano-measurement systems — including atomic force microscopes, scanning tunnelling microscopes, interferometers, focus-variation microscopes, stylus instruments, and others.

 

Together, the two sets illustrate the evolution of Croatian metrological excellence from the 1980s to the present day.

 

(First box: standards from 1985 | Second box: nano-standards from 2010)