C. Kuzu, E. Pelit, İ. Meral
DESIGN AND DEVELOPMENT OF HARDNESS INDENTATION MEASUREMENT SYSTEM AT TÜBİTAK UME

Developments in reference standards in Hardness Laboratory of TÜBİTAK UME (National Metrology Institute of Türkiye) and the demand received from calibration and testing laboratories forced us to develop a new hardness indentation measurement system (HIMS) that covers all Brinell, Vickers and Knoop hardness indentation measurements. In this design it has been aimed at automatization of measurements, constitution of different methods for determination of border of indentation and in turn measurement of the size (diameter and diagonal length) of indentations. In this paper design, installation and metrological characterization of HIMS developed by TÜBİTAK UME Hardness Laboratory is explained in detail.

Sun Qinmi, Li Haibin, Li Xuefei, Cheng Yuanyuan
DESIGN OF A NEW TYPE OF BUCHHOLZ HARDNESS TESTER

This paper describes a new type of Buchholz Indentation Hardness Tester used in Buchholz Indentation test for paint and varnishes. This new type tester uses a bridge structure to connect two cantilever sensors together, so we can instantly know the magnitude of the acting load on paint and varnishes. The design overcomes the defects of the previous load changes that could not be accurately predicted. At the same time we can use the adjustment hole to accurately adjust the level of the hardness tester, to ensure the standardization of the measurement process. By evaluating the uncertainty of the measurement results, the newly designed hardness tester ensures the accuracy and reliability of measurement results.

C. Kuzu, E. Pelit
A NEW APPROACH TO FORCE TRACEABILITY IN HARDNESS MEASUREMENTS

Force traceability in hardness measurements is provided via force measurement devices which are requested to have an accuracy Class 0,5 for hardness calibration machines, an accuracy Class 1 or accuracy of 0.2 % for hardness testing machines according to ISO 376 as indicated in the relevant ISO hardness standards. The most accurate way of having force traceability is to have the force measurement device calibrated against high accurate force standard systems. In this paper investigation and results of providing force traceability of force measurement instruments calibrated against deadweight type hardness standard machines is explained in detail.

C. Kuzu, E. Pelit, İ. Meral
INSTALLATION AND METROLOGICAL CHARACTERIZATION OF ROCKWELL-BRINELL-VICKERS HARDNESS STANDARD MACHINE AT TÜBİTAK UME

After successful implementation of two hardness standardizing machines at TSE (Turkish Standards Institution) in Rockwell and Brinell-Vickers hardness scales separately, it is aimed to combine them in a newer design and install in Hardness Laboratory of TÜBİTAK UME (National Metrology Institute of Türkiye). Design of such a national standard was made for Rockwell, Brinell and Vickers hardness scales within the scope of an internally funded project. In this paper installation and metrological characterization of the Rockwell-Brinell-Vickers hardness standard machine (RBVHSM) with dead weight force application system and laser interferometer developed by TÜBİTAK UME Hardness Laboratory is explained in detail.

M. Zackaria, F. Menelao, D. Nimptsch, T. Stegmaier, P. Beisel, P. Reinstaedt, U. Brand, R. Tutsch
UNIVERSAL AUTOMATION APPROACH FOR EFFICIENT CALIBRATION OF ROCKWELL HARDNESS REFERENCE BLOCKS

Hardness reference blocks play a pivotal role in ensuring traceability of hardness measurements. However, it is challenging to calibrate them in accordance with part three of the ISO 6508 without performing time-consuming pre-measurements. Previously, a method was developed and tested at the PTB for the Rockwell scale HRA which used data from the preload phase to automate the calibration process. We now present a novel method that extends the existing automation method to every standardised Rockwell scale. Furthermore, this method is universal in nature and not restricted to PTB’s standardised Rockwell hardness testing machine. Important parameters which pave the way towards the universal automation are addressed. The results of the established characteristic curves are validated by an interlaboratory comparison. This approach accelerates the entire calibration procedure, eliminates the need for an expert user and guarantees a standard-compliant measurement.