Your search for "Toshiyuki Takatsuji" returned 20 results

The dependence of Young-fringes contrast on both formation condition of specklegrams and readout condition of specklegrams has been investigated theoretically and experimentally. The ratio N of a periodic distance of the Young fringes to the average diameter of speckles forming the fringes determines the Young-fringes contrast. It is desired that the ratio N becomes larger than 1.1 in order to obtain fully developed Young fringes with a high contrast.

The National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ) developed nanometric lateral scales (design pitch: 25 nm) consisting of a GaAs/InGaP superlattice (multilayer) for atomic force microscope (AFM) and scanning electron microscope (SEM) calibration. The pitch of the fabricated nanometric lateral scales was measured using our AFM with a differential laser interferometer (DLI-AFM) and the uncertainty in the pitch measurements was evaluated. The average pitch and its expanded uncertainty (k = 2) were 25.39 nm and 0.43 nm, respectively. The quality of the developed scales was high enough to make them a suitable candidate for CRMs. On the basis of the obtained results in this technical study, the fabrication procedure and layout of the nanometric lateral scales will be optimized for the future distribution of these scales.

The results of the CCL key comparison on the calibration of a step gauge and ball bars are reported (CCL-K5). Nine NMIs participated in the comparison. The measured artifacts were a step gauge of 1000 mm length and three ball bars: two made from steel (400 mm and 800 mm in length) and one from Super Invar (800 mm long). The Key Comparison Reference Value (KCRV) for the step gauge was the mean of four laboratories, and the mean of all participants for the ball bars. The data for the step gauge have been analysed into constant and proportional components to reduce the quantity of data and separate out the random variation in measurements from proportional errors which generally have a different cause. All participating NMIs measured the step gauge and were generally in good agreement. Some results revealed problems with this measurement, and as such, helped to improve the measurement procedures of these NMIs for the future. Only a few NMIs delivered data for the ball bars and these results were in good agreement.

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 (MRA).

A simple method of evaluating the measurement capability of a practical Fizeau-type flatness measurement machine is proposed. In this method, by measuring only the peak-to-valley (PV) value of a calibrated test flat, the measurement capability of the flatness measurement machine for the PV value is evaluated while maintaining the traceability of the measurement. A simple approximate equation for estimating the measurement capability of the flatness measurement machine is presented.

The results of the APMP key comparison on step gauge (APMP.L-K5.2006) are reported. The transfer standard was provided by NMIJ, Japan. This standard has 620 mm nominal length and 32 measurement faces. Thirteen National Metrology Institutes (10 from APMP, 3 from other Regional Metrology Organizations) participated in this comparison. The comparison started in December 2005 and finished in December 2007. Participants have used different measurement techniques, which are normally used for calibration services. The measurement results are in good agreement except for three laboratories. For determining the key comparison reference values, all faces data from three laboratories and one (face 30) datum from one laboratory were excluded.

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).

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.

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).

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).

A spherical cat's-eye retroreflector made from a glass material having a refractive index of two was developed. The geometrical sphericity of the cat's eye and the sphericity examined optically were approximately 100 nm and 500 nm respectively. The discrepancy between these two values is discussed. This optical device is very versatile in terms of applications since it is free from viewing angle restrictions.

A laser tracking interferometer system developed by us is capable of measuring the coordinates of a target retroreflector. In this system, a self-calibration algorithm is used to determine system parameters such as the arrangement of laser trackers and the initial lengths of interferometers. The self-calibration algorithm is a least-squares method, hence in the algorithm a residue of measurement results is evaluated as a criterion of convergence. The relationship between the measurement error and the arrangement of the laser trackers was experimentally investigated. On the basis of these investigations, a new definition of the residue used in the self-calibration algorithm is proposed.

This paper proposes a calibration method for a coordinate measuring machine (CMM) using a laser tracking system. The laser tracking system can measure three-dimensional coordinates based on the principle of trilateration with high accuracy and is easy to set up. The accuracy of length measurement of a single laser tracking interferometer (laser tracker) is about 0.3 µm over a length of 600 mm. In this study, we first measured 3D coordinates using the laser tracking system. Secondly, 21 geometric errors, namely, parametric errors of the CMM, were estimated by the comparison of the coordinates obtained by the laser tracking system and those obtained by the CMM. As a result, the estimated parametric errors agreed with those estimated by a ball plate measurement, which demonstrates the validity of the proposed calibration system.