1,721,057 research outputs found
EURAMET supplementary comparison between INRiM and UME in Rockwell hardness scales (HRA - HRBW - HRC) - EURAMET.M.H-S1.a.b.c
Full text linkThis report describes a bilateral EURAMET Supplementary Comparison on Rockwell hardness scales of two national metrology institutes of Italy and Turkey, INRiM and UME, respectively. The pilot laboratory is INRiM in the comparison where three sets of hardness reference blocks for the Rockwell Hardness scales of HRA, HRBW and HRC were used. Each set of blocks consists of four hardness reference blocks for HRA and HRBW and five blocks for HRC hardness scales. The comparison was realized as planned in the Technical Protocol with some delay. The measurement results and uncertainty assessments declared by INRiM and UME are in consistency with each other
A suitable geometrical model for the verification of Knoop indenters with Gal-Indent optical system
Full text linkISO 4545-2 and 4545-3 of Knoop hardness tests require the geometrical verification of the indenter. INRiM hardness laboratory developed a specific measuring system, commercialized by Galileo-LTF as Gal-Indent optical system, which is used for the verification of Vickers indenters. This system is able to measure the vertex angles of the indenter between two opposite faces, and the four quadrilateral base angles. Using such quantities as inputs of a suitable geometrical model, the geometry of Knoop indenters can be verified. This work deals with the description of the system and the geometrical model
CCM pilot study overview: geometrical measurement of the Rockwell diamond indenter
Full text linkThis paper describes an overview of the capability of the NMIs that participated on the CCM Pilot Study measurement systems, conducted by the CIPM/CCM/Working Group on Hardness, to characterize the Rockwell hardness diamond indenter geometry, by measuring the included cone angle, the straightness of the generatrix, the spherical tip radius, the deviation of the local radius and the tilt angle. Nine NMIs took part in this study: INMETRO (Brazil); INRiM (Italy); KRISS (South Korea); NIM/PR (China); NIMT (Thailand); NIST (USA); PTB (Germany); TUBITAK UME (Turkey); VNIIFTRI (Russia), where INMETRO (Brazil) served as pilot laboratory
Verification of Knoop indenters with a Vickers-addressed optical system
No full textISO 4545-2 and 4545-3 of Knoop hardness tests require the geometrical verification of the indenters. INRiM hardness laboratory, in cooperation with Galileo-LTF®, has developed the Gal-Indent optical measuring system for the verification of Vickers indenters. This system can measure the vertex angles between two opposite faces, the quadrilateral base angles and the pyramid axis tilt angle. Using these measured quantities as inputs of a suitable geometrical model, the angles between the opposite edges at the vertex of Knoop indenters, nominally 172.5° and 130°, and the angle between the pyramid and indenter holder axes can be verified with an expanded uncertainty of 0.05°. Comparison of experimental measurements performed on three different Knoop indenters, previously verified by an accredited laboratory, shows compatible results. The proposed geometrical model could be easily implemented by laboratories that adopt similar measuring systems addressed for the verification of Vickers indenters without any modification of the experimental apparatus
Bilateral comparison in Rockwell C hardness scale between INRiM and GUM
Full text linkThis bilateral comparison in HRC is conducted in order to confirm the accuracy claimed by National Institute of Metrological Research in Italy (INRiM) and Central Office of Measures in Poland (GUM). Also, this study compares the difference of measurement results between two modernized deadweight-type Rockwell's hardness standard machines (HSMs) from GUM and primary hardness standard machine (PHSM) from INRiM. The hardness blocks of about 20 HRC, 35 HRC, 45 HRC, 50 HRC, 60 HRC and 65 HRC, which all have uniformity less then ±0.4 HRC according to EN ISO 6508-3, were used in this comparison
EURAMET key comparison between INRiM and UME in Vickers hardness scales (HV1 - HV30) - EURAMET.M.H-K1.b and c
Full text linkThis report describes the method and results of a bilateral EURAMET Key Comparison in Vickers hardness scales of two National Metrology Institutes (NMIs) of Italy and Turkey, INRiM and UME, respectively. The Pilot Laboratory (PL) is INRiM in the comparison in which one set of hardness reference blocks with three hardness levels for the Vickers Hardness scales of both HV1 and HV30 was used. The comparison was realized as planned in the Technical Protocol with some delay. The aim of this comparison is to link the UME measurement results to the CCM.H-K1.b.c through the PL (INRiM) as a participant of the CCM key comparison. The measurement results and uncertainty assessments declared by INRiM and UME are in consistency with each other and UME results are also in consistency with the CCM.H-K1.b.c Key Comparison Reference Values (KCRVs). The CCM.H-K1.b.c was realized during 2001 to 2003 to investigate the metrological equivalence of national standards among national metrology institutes (NMIs) within the CCM
Practical Implications to the Improvement of Hardness scale definitions
No full textRecently, in the framework of the Working Group on Hardness (WGH) of the Consultative Committee for Mass and Related Quantities (CCM) of the Comité International des Poids et Mesures (CIPM), the opportunity to improve the definitions of the hardness scales has been discussed. In this paper is investigated, from the theoretical point of view, the benefits in terms of decreasing of uncertainty subsequently to the approval of new definitions. The analysis will be done on the most important Rockwell, Vickers and Brinell hardness scales, but it will be possible to extend the benefits easily to all other scales
- …
