A metrology-based Rockwell hardness scale is established by a standard machine and a standard diamond indenter. Both must be established through force and dimensional metrology with acceptably small measurement uncertainties. In 1994, NIST developed a microform calibration system for the calibration of standard Rockwell diamond indenters. This was based on a stylus instrument using calibration and check standards, and NIST-developed calibration and uncertainty procedures. These calibrations are traceable to dimensional standards. Since 1995, about 100 indenters have been calibrated at NIST. These calibrations show high accuracy and long term reproducibility. One of these indenters was selected as the primary standard indenter for the establishment of the U.S. Rockwell hardness scales with metrological traceability, stability and reproducibility.
Proceedings Title: 15th World Congress of International Measurement Confederation Proceedings
Conference Dates: December 23, 1998
Conference Location: Osaka, -1
Conference Title: International Measurement Confederation
Pub Type: Conferences
diamond intender, Rockwell hardness, traceability