Antti Lassila, Jorma Jokela, Markku Poutanen, Xu Jie
Measurement of a baseline with Väisälä interferometer is a traditional high accuracy length measurement in geodesy. An accurate length up to 1 km is achievable by interferometrically multiplying the length of a 1 m quartz bar. Therefore, the absolute length of the bar should be known with small uncertainty. A measurement setup and procedure for calibration of length of a quartz bar by combined white and laser light gauge block interferometer has been developed. The calibration procedure, results and uncertainty evaluation are presented. A standard uncertainty of 35 nm has been achieved.
XVII IMEKO World Congress
· TC14
· 2003
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Lifong Zou, Dayananda Samarawickrama, Kevin Seymour, Ken Stout
Quality control is applied to almost every procedure during the manufacturing process in industry. However, it is not used commonly in restorative dental practice. The surface contour or shape of the tooth is very irregular, a 'so called' free form surface. Measurement of such a free form surface needs a specified strategy to satisfy the measurement accuracy. This paper attempts to propose an optimal measurement strategy to measure the occlusal molar tooth surface, in order to achieve a degree of measurement and quality control in restorative dental practice.
XVII IMEKO World Congress
· TC14
· 2003
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Tanfer Yandayan
A new design of mechanical gauge block comparator for calibration of long gauge blocks is described. The comparator is constructed by modification of a commercially available universal length measuring machine. It is able to compare the different nominal size gauge blocks with its 300 mm measurement range. This has the advantage that a reference metric size gauge block can be used to calibrate the inch size square or rectangular section gauge blocks or vice-versa. Line scale of the length-measuring machine, which is calibrated by a laser interferometer and gauge blocks, is used for the...
XVII IMEKO World Congress
· TC14
· 2003
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Sarwat Zahwi, Monier Koura, Alia Mekawi
The nominal conditions for measuring surface roughness when using stylus instruments are specified in ISO 3274. Deviations from these nominal conditions lead to significant deviations of the measured roughness parameters. An uncertainty evaluation has been made on five roughness parameters for three calibration standards. The methods and procedures for uncertainty evaluation are to i) calibrate and evaluate the uncertainty in the condition for the measuring instrument, ii) evaluate the influence of each individual deviation on the results of measurement, and iii) combine the effect of these...
XVII IMEKO World Congress
· TC14
· 2003
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A. Titov, I. Malinovsky, C.A. Massone
New calibrated double-sided method of interferometric length measurements with quartz reference plate is reported. The method is free from wringing errors, and can be used for the improvement of measurements of material artefacts. Limitations of the interferometric measurements are discussed. Some systematic errors are measured with a sub-nanometer resolution.
XVII IMEKO World Congress
· TC14
· 2003
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K. Umetsu, R. Furutani, T. Takatsuji, S. Osawa, T. Kurosawa
A new calibration approach of a coordinate measuring machine (CMM) using a laser tracking system is proposed. According to the conventional approach of the laser tracking system, trilateration principle is mainly adapted. Therefore one retroreflector and four laser trackers are required. Though this approach is capable of attaining high accuracy measurement, measuring volume is likely to become smaller due to physical limitations for middle size CMM. Consequentially, we need new approach, which uses the least laser trackers in numbers. In this paper, effective calibration strategy to...
XVII IMEKO World Congress
· TC14
· 2003
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Ch. Papageorgiou, Th. Laopoulos
This paper introduces a different approach to the measurement of the time-of-flight of ultrasonic signals. Frequency variation monitoring and recording is used to determine accurately the arrival time of the ultrasonic signal. A high speed Digital Signal Processor (D.S.P.) is used for both: transmission and direct measurement of the frequency of the incoming signal in every single period and with an accuracy of about 0.1%. The proposed configuration offers small size and low cost solution to displacement measurements with a remarkable performance in terms of accuracy, range and measurement...
XVII IMEKO World Congress
· TC14
· 2003
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José Sánchez, Saúl Santillán, Sergio Padilla, Benjamín Valera, Rigoberto Nava, Gerardo Ruiz
Abstract - One purpose of Virtual Instrumentation in Metrology, is to empathise properties that put instrumentation away from idealisations. In actual instrumentation, geometric deviations trend to occur in relations 10 -5 , 10 -7 of maximum displacements, requiring their representation in amplified way. If distortion of mechanisms is amplified hundreds times for its representation in CAD, many problems occur: linearity is lost between geometric relations; it is difficult to represent errors simultaneously for many axis and many degrees of freedom; operation of mechanisms doesn't satisfy...
XVII IMEKO World Congress
· TC14
· 2003
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Ken Shimojima, Ryoshu Furutani, Kiyoshi Takamasu, Kenji Araki
Articulated Coordinate Measuring Machines (A-CMM) are commercial products. However, it is difficult to keep the traceablity of it, because the calibration of A-CMM is performed by the manufacturer’s own method. We planed to use 3D artifact, which had 9 balls for calibration, and test it. The kinematical model of A-CMM was described in D-H notation. In A-CMM measurement, a cone-shaped stylus was used. We measured the artifact in five different locations and orientations. Because the artifact has nine balls, 45 points in total ware measured. the parameters were determined in each location and...
XVII IMEKO World Congress
· TC14
· 2003
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Atsushi Taguchi, Takashi Miyoshi, Yasuhiro Takaya, Satoru Takahashi
With the advance of microtechnology, inprocess or in situ measurement techniques for measuring surface profiles of engineered micro parts have been increasingly required. We have proposed an optical measurement technique, the optical inverse scattering phase method, which can be applied to the in-process measurement of micro-surface profile with the accuracy in the nanometer order. An instrument has been designed and developed on the basis of the proposed principles, and verified by measuring an ultra precision grid plate having rectangular pockets 44nm deep at intervals of 10µm. The...
XVII IMEKO World Congress
· TC14
· 2003
· Download