Determination Model of Phase-Change Correction for High Precision Gauge Block Calibration

AbstractWhen gauge blocks are calibrated by the laser interferometer technique, phase-change corrections play a crucial role in the measurement uncertainties. In order to reduce the source of uncertainty, phase-change correction must be known and be compensated to the measured results. We present here a determination based on knowledge gained from the stacking method and the known value of phase correction of quartz. It is a fast and robust method. Phase-change correction of any pair of auxiliary plates and gauge blocks can be calculated by using our model. This method is suitable for the national metrological institutes (NMIs), calibration laboratories and industries where calibration of various gauge block materials are carried out and measurement uncertainty within 30 nm is adequate. The experimentally observed phase-change corrections were compared with the calculated values according to our model. The comparison illustrates a good agreement. The measurement uncertainty of gauge block calibration using our interferometer system is 24 nm

Development of the Probe Calibration System for the Roundness Measuring Machine

AbstractThe calibration system of the probing system used in roundness measuring instrument has been developed at the national institute of metrology (Thailand), NIMT. The calibration system was designed, constructed, validated and used to calibrate sensitivity and linearity of the probing system. This calibration system can help to reduce use of magnification setting standards which are need to be calibrated by the oversea national metrology institutes (NMIs) in order to retain traceability chain to the SI unit. The calibration system does not only help in reducing expense due to purchasing, maintenance and calibration of the magnification standard but also yield a measurement technology that can be transferred to the industries. The measurement uncertainty for the roundness measurement is [9.4, 0.01×R] nm where R is the measured roundness error of the workpiece in nm

Final report on APMP regional key comparison APMP.L-K6: Calibration of ball plate and hole plate

open14sìThe comparison in this Final Report is part of the CIPM-MRA (Comité International des Poids et Mesures - Mutual Recognition Arrangement). The Report is also available in the open-access KCDB (Key Comparison Data Base) through the website of the BIPM (Bureau International des Poids et Mesures, www.bipm.org).The results of the APMP key comparisons on ball plate and hole plate (APMP.L-K6.2007) are reported. Both transfer standards were provided by NMIJ, Japan. The ball plate standard is 532 mm by 532 mm in nominal dimension and 25 spheres are embedded. Thirteen National Metrology Institutes (8 from APMP, 5 from other Regional Metrology Organizations) participated in the ball plate measurement comparison. The hole plate standard is 550 mm by 550 mm in nominal dimension and there are 44 cylindrical holes in it. Nine National Metrology Institutes (5 from APMP, 4 from other Regional Metrology Organizations) participated in the hole plate measurement comparison. The comparison started in May 2006 and finished in October 2008. The participants used different measurement techniques which were used for their routine calibration services. For determining the key comparison reference values, a two-dimensional coordinates-based analysis was performed. The measurement results on the ball plate show good agreement in ten out of thirteen participants. In contrast, those on the hole plate are in agreement for five out of nine participants.Takatsuji, Toshiyuki; Eom, Taebong; Tonmueanwai, Anusorn; Yin, Ruimin; van der Walt, Floris; Gao, Sitian; Thu, Bui Quoc; Singhal, R P; Howick, Eleanor; Doytchinov, Kostadin; Valente de Oliveira, José Carlos; Lassila, Antti; O'Donnell, Jim; Balsamo, AlessandroTakatsuji, Toshiyuki; Eom, Taebong; Tonmueanwai, Anusorn; Yin, Ruimin; van der Walt, Floris; Gao, Sitian; Thu, Bui Quoc; Singhal, R. P; Howick, Eleanor; Doytchinov, Kostadin; Valente de Oliveira, José Carlos; Lassila, Antti; O'Donnell, Jim; Balsamo, Alessandr

APMP L-K4 Key Comparison, Calibration of diameter standards

A regional key comparison, APMP.L-K4, was held in 2008. To demonstrate the equivalence of routine calibration services offered by NMIs to clients, participants in this APMP.L-K4 comparison agreed to use the same apparatus and methods as routinely applied to client gauges. There are 14 laboratories from NMIs involved this key comparison, which included CMS/ITRI, NMIJ/AIST, NPL-I, NIMT, Puslit KIM-LIPI, NMISA, MSL, NMIA, NML-SIRIM, VMI, KRISS, SCL, NMC/A*STAR and NSCL. This report describes the measurement results of five diameter standards including two rings and three plugs. The calibrations of this key comparison were carried out by laboratories during the period from May 2008 to November 2010. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA

Angle comparison using an autocollimator

Autocollimators are versatile optical devices for the contactless measurement of the tilt angles of reflecting surfaces. An international key comparison (KC) on autocollimator calibration, EURAMET.L-K3.2009, was initiated by the European Association of National Metrology Institutes (EURAMET) to provide information on the capabilities in this field. The Physikalisch-Technische Bundesanstalt (PTB) acted as the pilot laboratory, with a total of 25 international participants from EURAMET and from the Asia Pacific Metrology Programme (APMP) providing measurements. This KC was the first one to utilise a high-resolution electronic autocollimator as a standard. In contrast to KCs in angle metrology which usually involve the full plane angle, it focused on relatively small angular ranges (±10 arcsec and ±1000 arcsec) and step sizes (10 arcsec and 0.1 arcsec, respectively). This document represents the approved final report on the results of the KC