scholarly journals Three-Dimensional Temperature Measurement by Laser-Holographic Interferometry. Numerical Simulation of Light Deflection and Its Quantitative Compensation for Measurement Error.

1994 ◽  
Vol 37 (4) ◽  
pp. 912-917 ◽  
Author(s):  
Seizo Kato ◽  
Naoki Maruyama
Keyword(s):  
Numerical Simulation ◽  
Measurement Error ◽  
Temperature Measurement ◽  
Holographic Interferometry ◽  
Three Dimensional ◽  
Light Deflection ◽  
Laser Holographic Interferometry

Distortion in Thermal Field Around Inserted Thermocouples in Experimental Interfacial Studies, Part 4: End Effect

2000 ◽  
Vol 124 (1) ◽  
pp. 135-145 ◽  
Author(s):  
M. H. Attia ◽  
A. Cameron ◽  
L. Kops
Keyword(s):  
Finite Element ◽  
Measurement Error ◽  
Temperature Measurement ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Solid Material ◽  
Filler Material ◽  
Sensing Element ◽  
Element Analysis ◽  
Parametric Finite Element Analysis

The main objective of this investigation is to develop a model for predicting the systematic temperature measurement error due to the thermal disturbance in the region surrounding the thermocouple hot junction. A parametric finite element analysis has been conducted to model the general case of a three-dimensional thermocouple installation inserted in a blind hole. The variables considered in this study are the level of the heat flux in the measurement zone, as well as the thermal characteristics of the thermocouple wires, the filler material (cement), and the solid material in which the installation is placed. Analysis of the results showed that the pattern of the disturbed temperature field around the thermocouple sensing element is critically dependent on the ratio between the thermal conductivities of the filler material and the solid material. The results also showed that a reduction in the temperature gradient in the undisturbed field results in a considerable increase in the partial heat flow into the thermocouple wires, and consequently a significant systematic temperature measurement error. The effect of the eccentric positioning of the thermocouple on the uncertainty limits of the measurement error was found to be quite significant. A generalized model is presented to estimate the measurement error for any combination of the thermocouple installation attributes. Experimental verification of some aspects of this analysis has been carried out using a well-controlled experiment in which the thermocouple hole is scale-modelled. Comparison of the test results with the finite element predictions confirmed the accuracy and validity of the numerical modelling and results.

Laser Interferometry Hologram Registration for Three-Dimensional Precision Measurements

2006 ◽  
Vol 128 (4) ◽  
pp. 1006-1013 ◽  
Author(s):  
Zhenhua Huang ◽  
Albert J. Shih ◽  
Jun Ni
Keyword(s):  
Holographic Interferometry ◽  
Three Dimensional ◽  
Surface Profile ◽  
Laser Interferometry ◽  
Depth Of Field ◽  
Registration Method ◽  
Dimensional Precision ◽  
Data Registration ◽  
Cross Correlation Analysis ◽  
Laser Holographic Interferometry

A hologram registration method is developed for the laser holographic interferometry measurement of the 3D surface profile of objects which are larger than the field of view (FOV). The theory of laser holographic interferometry, including the phase-shifting and multiwavelength tuning, is described. The hologram registration without using targets is elaborated. The cross-correlation analysis is used to find the translation and overlapped regions, which determine the tilt and shift correction for data registration. The proposed method is validated using two examples with different approaches. The first example, a wheel hub, is smaller than the FOV and demonstrates only 0.1μm discrepancy of the surface flatness between the registered and standard measurements. The second example, an engine combustion deck surface, is larger than the FOV. The registered surface measurements are compared to that of coordinate measurement machine (CMM) with only 2.5% discrepancy of the peak-to-valley flatness. This data registration method enables the sub-μm precision and large depth of field (several centimeters) measurement of large size objects.

Laser Interferometry Hologram Registration for Three-Dimensional Precision Measurements

2006 ◽  
Author(s):  
Z. Huang ◽  
A. J. Shih ◽  
J. Ni
Keyword(s):  
Holographic Interferometry ◽  
Three Dimensional ◽  
Laser Interferometry ◽  
Depth Of Field ◽  
Measurement Technology ◽  
Registration Method ◽  
Dimensional Precision ◽  
Data Registration ◽  
Cross Correlation Analysis ◽  
Laser Holographic Interferometry

Laser holographic interferometry is an advanced precision measurement technology with sub-μm accuracy and large, over 17 mm, depth-of-field. The limitation of current laser holographic interferometry is the limited measurement area, which cannot be larger than the field of view (FOV). A hologram registration method without using targets is developed to overcome this problem. The theory of laser holographic interferometry, including the phase-shifting and multi-wavelength tuning, is described. The cross-correlation analysis is used to find the translation and overlapped regions, which determine the tilt and shift correction for data registration. The proposed method is validated using two examples with different approaches. The first example, a wheel hub, is smaller than the FOV and demonstrates only 0.1 μm discrepancy of the surface flatness between the registered and standard measurements. The second example, an engine combustion deck surface, is larger than the FOV. The registered surface measurements are compared to that of coordinate measurement machine (CMM) with only 2.5% discrepancy of the peak-to-valley flatness. This data registration method enables the sub-μm precision and large depth of field (several centimeters) measurement of large size objects.

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