STUDY OF THE BEST MEASUREMENT CAPABILITY IN ROCKWELL SCALE AT THE BRAZILIAN NMI INMETRO'S PRIMARY HARDNESS STANDARD MACHINE
Jorge Trota Filho, Sérgio Pinheiro de Oliveira, Islei Domingues da Silva, Renato Reis Machado, Cláudio Afonso Koch
Abstract:
This paper shows the actual status of an on-going metrological research that aims an upgrade of the current Rockwell C hardness scale´s best measurement capability (BMC), e.g. 0.3 HRC, referred to the Primary Hardness Standard Machine installed at the Brazilian NMI INMETRO. This value complies with the ISO hardness standards and the GUM uncertainty guide as well as the main eight uncertainty sources and respective sensitivity coefficients for the direct calibration method, detailed in the EURAMET hardness guide. This work shows that an increasing knowledge of the actual calculated sensitivity coefficients yields a consequent reduction in the BMC. These experimental coefficients were estimated by the use of up to six uncertainty sources. In this case, the BMC changed to 0.17 HRC (two significant digits) or 0.2 HRC (one significant digit).
Keywords:
Rockwell C hardness, hardness calibration, best measurement capability
Download:
IMEKO-WC-2009-TC5-548.pdf
DOI:
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Event details
Event name:
XIX IMEKO World Congress
Title:

Fundamental and Applied Metrology

Place:
Lisbon, PORTUGAL
Time:
06 September 2009 - 11 September 2009
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