The colour, with the particularity to be defined simultaneously as a physical quantity and as a psychophysical quantity, is one of the concepts that can link hard sciences and behavioural sciences. From the viewpoint of behavioural sciences colours are basically measured with nominal scales, and in hard science colours are measured with interval scales. Our hypothesis is that the main relation that must be preserved during colour measurement is a metric. We suggest then that colours must be measured with metrical scales. The fuzzy metrical scale is preferred due to the possibility to define it like a nominal scale.

Development of reference hardness blocks for the high hardness range by the powder metallurgy process will be presented in this paper. Development would start with the selection of powder, matrix and grain growth inhibitors as well as parameters related to the technological process of obtaining which are related to milling, compacting and sintering. Mentioned would be realized in order to ensure the measurement traceability of the Vickers hardness for the Republic of Croatia for the high hardness range and to contribute to the spectrum of materials and processes of manufacturing reference blocks for the Vickers hardness on the global level.

I-Chih Ni, Sheau-shi Pan, Jian-Lin Huang, Sheng-Jui Chen The Primary Rockwell Hardness Standard System was set up in the Center for Measurement Standards since July 1996 till June 1997. During the time, a laser interferometer, HP10737R 3-axis compact interferometer system was used to measure the effect of pitch and yaw of the Rockwell Hardness machine. While the geometry of the diamond was not determined. In order to increase the performance of hardness measurement .In this paper, we will present the results of indenter geometry by µ-CMM in CMS.

The current paper describes the results of measurements conducted during the improvement of the national primary hardness standard machine on Vickers scales. As a result of improvement, the range of applied loads has been expanded from 0,098 N to 0,0098 N. This helped to provide the uniformity of hardness measurements on Vickers scales HV0,005, HV0,002 and HV0,001, expand the standard machine application area as well as reduce measurements uncertainty on the primary standard machine as a result of studying geometrical parameters of reference indenters with the help of a new high-precision complex. A base for the development of a new national hardness standard machine in the field of nanoindentation at the loads of less than 0, 0098 N has been created.

Conventional rebound hardness tests like Shore and Leeb hardness tests are mainly applied for massive and large specimens like mill roll. For small or thin specimens, however, “mass effect,” i.e., loss of impact energy due to vibration of specimens during impact cannot be ignored. Nakamura and Maki proposed a simple rebound hardness test using a small ball indenter that is expected to reduce the mass effect.
In this paper, we developed a prototype of a free-fall-type rebound hardness tester and carried out experiments to provide fundamental information necessary to establish Nakamura-Maki method industrially.
Impact velocity and rebound velocity of ball indenters are estimated from free-fall height and rebound height, respectively. Experimental parameters are impact velocity, size, and materials of ball indenters. The most important result obtained is that coefficient of restitution, i.e., rebound hardness, is almost independent of the size of ball indenters and the rebound hardness scale can be set once other experimental parameters were fixed. Further study will be necessary to optimize experimental conditions and to measure accurate impact and rebound velocities in order to realize a versatile tester based on Nakamura-Maki method.