scholarly journals Precise linear measurements using a calibrated reference workpiece without temperature measurements

2018 ◽  
Vol 7 (2) ◽  
pp. 609-620 ◽  
Author(s):  
Dmytro Sumin ◽  
Rainer Tutsch
Keyword(s):  
Thermal Expansion ◽  
Measurement Uncertainty ◽  
Temperature Measurements ◽  
Coordinate Measuring Machines ◽  
Measuring Instrument ◽  
Linear Measurements ◽  
Linear Measuring ◽  
Require Temperature ◽  
Linear Measuring Instrument

Abstract. We suggest a procedure for the correction of the errors caused by thermal expansion of a workpiece and the scale of a linear measuring instrument (coordinate measuring machines, length measuring machines, etc.) when linear measurements are performed at nonstandard temperature. We use a calibrated reference workpiece but do not require temperature measurements. An estimation of the measurement uncertainty and application examples are given.

scholarly journals Evaluation and Optimization of Task-oriented Measurement Uncertainty for Coordinate Measuring Machines Based on Geometrical Product Specifications

2018 ◽  
Vol 9 (1) ◽  
pp. 6 ◽  
Author(s):  
Yinbao Cheng ◽  
Zhongyu Wang ◽  
Xiaohuai Chen ◽  
Yaru Li ◽  
Hongyang Li ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Evaluation Model ◽  
Optimization Method ◽  
Practical Significance ◽  
Measuring Instruments ◽  
Coordinate Measuring Machines ◽  
Measurement Instruments ◽  
Practical Applications ◽  
Geometric Product ◽  
Task Oriented

Measuring instruments are intended to be intelligent, precise, multi-functional and developing multidirectionally, scientific, and reasonable; the reliable evaluation of measurement uncertainty of precision instruments is also becoming more and more difficult, and the evaluation of the Coordinate Measuring Machines (CMM) measurement uncertainty is among the typical problems. Based on Geometric Product Specification (GPS), this paper has systematically studied the CMM uncertainty for evaluating the size and geometrical errors oriented toward measurement tasks, and thus has realized the rapid and reliable evaluation of the CMM uncertainty for task-oriented measurement. For overestimation of the CMM uncertainty for task-oriented measurements in the initial evaluation, a systematic optimization solution has been proposed. Finally, the feasibility and validity of the evaluation model and the optimization method have been verified by three different types of measurement examples of diameter, flatness and perpendicularity. It is typical and representative to systematically solve the problem of the CMM uncertainty for evaluating the measurement tasks targeted at dimensions and geometric errors, and the research contents can be effectively applied to solve the uncertainty evaluation problems of other precision instruments, which are of great practical significance not only for promoting the combination of modern uncertainty theory and practical applications but also for improving the application values of precision measurement instruments.

scholarly journals Research of three dimensional laser scanning coordinate measuring machine

2018 ◽  
Vol 232 ◽  
pp. 02015
Author(s):  
Zhihua Jiang ◽  
Wenjian Zhang ◽  
Lizhen Cui
Keyword(s):  
3D Printing ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Coordinate Measuring Machine ◽  
Coordinate Measuring Machines ◽  
Measuring Instrument ◽  
Calibration System ◽  
Measuring Range ◽  
Measuring Machine

Three dimensional laser scanning coordinate measuring machine is suitable for the measurement of 3D printing products, and its measuring range depends on the three coordinate measuring machine. It is the main 3D printing product measuring instrument [1]. In this paper, the principle of laser scanning three coordinate measuring machine is analyzed. The accuracy and reliability of the calibration system for 3D printing products are verified. According to the newly revised JJF 1064 Calibration specification for coordinate measuring machines [3], it is calibrated.

Geometriemessungen auf Werkzeugmaschinen*/Geometric measurements on machine tools - Minimization and calculation of measurement uncertainty

2016 ◽  
Vol 106 (11-12) ◽  
pp. 782-786
Author(s):  
M. Ohlenforst ◽  
P. Dahlem ◽  
M. Peterek ◽  
R. Prof. Schmitt
Keyword(s):  
Measurement Uncertainty ◽  
Machine Tools ◽  
Shop Floor ◽  
Coordinate Measuring Machines ◽  
Time Saving ◽  
Specific Measurement ◽  
Large Measurement ◽  
Measurement Uncertainties

Geometriemessungen auf Werkzeugmaschinen sind immer häufiger gefragt. Insbesondere bei der Großbauteileproduktion bieten sie ein hohes Potential, um Kosten und Zeit zu sparen. Anders als Koordinatenmessgeräte sind Werkzeugmaschinen rauen Umgebungsbedingungen von Produktionshallen ausgesetzt, welche die Messungen deutlich beeinflussen können. Der Fachbericht befasst sich mit einem Vorgehen, um umweltbedingte Störeinflüsse und die damit induzierten Messunsicherheiten zu bestimmen und zu reduzieren.   Geometric measurements on machine tools are getting more and more important for the production of large parts due to the big cost and time saving potential. Unlike coordinate measuring machines, machine tools are exposed to rough shop floor conditions generating large measurement uncertainties. The article describes a procedure to define and reduce these disturbances and the specific measurement uncertainties.

Measurement uncertainty assessment of Coordinate Measuring Machines by simulation and planned experimentation

2011 ◽  
Vol 4 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Francesco Aggogeri ◽  
Giulio Barbato ◽  
Emanuele Modesto Barini ◽  
Gianfranco Genta ◽  
Raffaello Levi
Keyword(s):  
Measurement Uncertainty ◽  
Uncertainty Assessment ◽  
Coordinate Measuring Machines

scholarly journals Application Of Bias Randomization In Evaluation Of Measuring Instrument Capability

2015 ◽  
Vol 22 (4) ◽  
pp. 513-520
Author(s):  
Paweł Fotowicz
Keyword(s):  
Measurement Uncertainty ◽  
Significant Role ◽  
Gaussian Distribution ◽  
Uncertainty Budget ◽  
Systematic Effect ◽  
Measuring Instrument ◽  
Rectangular Distribution ◽  
Modern Metrology ◽  
Randomization Method ◽  
Instrument Quality

Abstract The paper deals with the problem of bias randomization in evaluation of the measuring instrument capability. The bias plays a significant role in assessment of the measuring instrument quality. Because the measurement uncertainty is a comfortable parameter for evaluation in metrology, the bias may be treated as a component of the uncertainty associated with the measuring instrument. The basic method for calculation of the uncertainty in modern metrology is propagation of distributions. Any component of the uncertainty budget should be expressed as a distribution. Usually, in the case of a systematic effect being a bias, the rectangular distribution is assumed. In the paper an alternative randomization method using the Flatten-Gaussian distribution is proposed.

scholarly journals Calibration bath uncertainty in precision temperature measurements

2019 ◽  
pp. 9-13
Keyword(s):  
Temperature Gradient ◽  
Measurement Uncertainty ◽  
Temporal Stability ◽  
Temperature Stability ◽  
Bath Temperature ◽  
Temperature Measurements ◽  
Temperature Control System ◽  
Radial Temperature ◽  
Working Volume ◽  
Precision Temperature

Calibration baths are widely used in many laboratories worldwide for the calibration of thermometers by comparison. They come in different shapes and sizes and use different media (water, alcohol, silicon oil etc.), but a certain nonuniformity of theused media is always present. During precision temperature measurements, uniformity (homogeneity and temporal stability) of a calibration bath is of the utmost importance since its contribution to total measurement uncertainty is the largest. The temperature gradient can be described as a change of temperature at different positions inside the bath working volume. Temporal temperature stability depends on many factors such as: the bath temperature, control system, bath construction and the flow of the used media inside the bath, just to name a few. In this paper, we investigate uniformity of a cylindrical calibration bath. Homogeneity is determined by measurement of axial and radial temperature gradient inside the bath. Stability is examined by observation of the change in temperature reading during certain period of time. The obtained results are compared with manufacturer specification and can be used for determination of calibration bath contribution to total measurement uncertainty during calibration of thermometers.

A Virtual Instrument for SEM Uncertainty Analysis

2014 ◽  
Vol 613 ◽  
pp. 101-107
Author(s):  
Dominic Gnieser ◽  
Carl Georg Frase ◽  
Harald Bosse ◽  
Rainer Tutsch
Keyword(s):  
Measurement Uncertainty ◽  
Virtual Instrument ◽  
Metrological Traceability ◽  
Measuring Instrument ◽  
Measurement Instruments ◽  
External Disturbances ◽  
Optical Lens ◽  
Parameters Uncertainty ◽  
Essential Components ◽  
Virtual Measuring Instrument

To assure the metrological traceability of a measurement, it is required to perform an analysis of the measurement uncertainty specific to the measurement task. An approach to estimate the measurement uncertainty for complex systems is the so-called virtual measuring instrument: The measuring process is simulated taking into account its influencing parameters and a statistical analysis is performed by means of Monte-Carlo calculations. We present the development of such a virtual measuring instrument for scanning electron microscopy (SEM) which allows to estimate the measurement uncertainty in compliance with GUM for dimensional measuring tasks in nano- and microsystems technology. By application of this virtual instrument, model based corrections of systematic errors are made possible and the cognition of the strength of different perturbing influences can lead to recommendations to optimize measurement instruments and methods. The virtual model programmed in MATLAB is called ‘vREM’, it includes all essential components of the measuring chain of an SEM as modules: The electron source, the electron-optical lens-system, the scan-generator, the interaction of the electrons within the object, electron detectors, simple analysis procedures and consideration of external disturbances. By adjusting parameters uncertainty contributions can be assigned to the virtual probe, the virtual specimen and the virtual detector signals.

Sign in / Sign up

Export Citation Format

Share Document