Experimental study on measurement accuracy of hot disk thermal constants analyser

2008 ◽  
Author(s):  
Qiang Wang ◽  
Jingmin Dai ◽  
Chunsuo Xin
Keyword(s):  
Experimental Study ◽  
Measurement Accuracy ◽  
Thermal Constants ◽  
Hot Disk

scholarly journals Experimental Study on 3D Measurement Accuracy Detection of Low Altitude UAV for Repeated Observation of an Invariant Surface

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Sha Gao ◽  
Shu Gan ◽  
Xiping Yuan ◽  
Rui Bi ◽  
Raobo Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
Unmanned Aerial Vehicle ◽  
Structure From Motion ◽  
Measurement Accuracy ◽  
Test Plot ◽  
3D Measurement ◽  
Difference Model ◽  
Repeated Observations ◽  
Aerial Vehicle ◽  
Low Altitude

Low-altitude unmanned aerial vehicle (UAV) photogrammetry combined with structure-from-motion (SFM) algorithms is the latest technological approach to imaging 3D stereo constructions. At present, derivative products have been widely used in landslide monitoring, landscape evolution, glacier movement, volume measurement, and landscape change detection. However, there is still a lack of research into the accuracy of 3D data positioning based on the structure-from-motion of unmanned aerial vehicle (UAV-SFM) technology, itself, which can affect the measurable effectiveness of the results in further applications of this technological approach. In this paper, validation work was carried out for the DJI Phantom 4 RTK UAV, for earth observation data related to 3D positioning accuracy. First, a test plot with a relatively stable surface was selected for repeated flight imaging observations. Specifically, three repeated flights were performed on the test plot to obtain three sorties of images; the structure from motion and multi-view stereo (SFM-MVS) key technology was used to process and construct a 3D scene model, and based on this model the digital surface model (DSM) and digital orthophoto map (DOM) data of the same plot with repeated observations were obtained. In order to check the level of 3D measurement accuracy of the UAV technology itself, a window selection-based method was used to sample the point cloud set data from the three-sortie repeat observation 3D model. The DSM and DOM data obtained from three repeated flights over the surface invariant test plots were used to calculate the repeat observation 3D point errors, taking into account the general methodology of redundant observation error analysis for topographic surveys. At the same time, to further analyze the limits of the UAV measurement technique, possible under equivalent observation conditions with the same processing environment, a difference model (DOD) was constructed for the DSM data from three sorties, to deepen the overall characterization of the differences between the DSMs obtained from repeated observations. The results of the experimental study concluded that both the analysis of the 3D point set measurements based on window sampling and the accuracy evaluation using the difference model were generally able to achieve a centimeter level of planimetric accuracy and vertical accuracy. In addition, the accuracy of the surface-stabilized hardened ground was better, overall, than the accuracy of the non-hardened ground. The results of this paper not only probe the measurement limits of this type of UAV, but also provide a quantitative reference for the accurate control and setting of an acquisition scheme of the UAV-based SfM-MVS method for geomorphological data acquisition and 3D reconstruction.

Parameter estimations for measurements of thermal transport properties with the hot disk thermal constants analyzer

2000 ◽  
Vol 71 (6) ◽  
pp. 2452-2455 ◽  
Author(s):  
Vlastimil Bohac ◽  
Mattias K. Gustavsson ◽  
Ludovit Kubicar ◽  
Silas E. Gustafsson
Keyword(s):  
Transport Properties ◽  
Thermal Transport ◽  
Parameter Estimations ◽  
Thermal Transport Properties ◽  
Thermal Constants ◽  
Hot Disk

313 Experimental study on the measurement accuracy of DHPIV

2005 ◽  
Vol 2005.2 (0) ◽  
pp. 217-218
Author(s):  
Takahiro YAMAGUCHI ◽  
Shigeru MURATA
Keyword(s):  
Experimental Study ◽  
Measurement Accuracy

Specific Heat Measurements with the Hot Disk Thermal Constants Analyser

2021 ◽  
pp. 56-65
Author(s):  
M. Gustavsson ◽  
N. S. Saxena ◽  
E. Karawacki ◽  
S. E. Gustafsson
Keyword(s):  
Specific Heat ◽  
Thermal Constants ◽  
Hot Disk

Effect of Tee and Valve on the Flow Measurement Accuracy for Turbulent Pipe Flow With Flow Conditioner

2011 ◽  
Author(s):  
Boualem Laribi ◽  
Nahla Bouricha
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Pipe Flow ◽  
Flow Measurement ◽  
Measurement Accuracy ◽  
Stokes Equations ◽  
Turbulent Pipe Flow ◽  
Navier Stokes ◽  
Turbulent Model ◽  
Navier Stokes Equations

This work describes the effect of a Tee and a Valve on the flow measurement accuracy and the performances of the E´toile flow straightener described by the standard ISO 5167 to produce the fully developed pipe flow with these disturbances. Simulation is carried out for an air flow in 100mm pipe diameter with a Reynolds number between 104 and 106. The code used for this work is Fluent V6.3, where the Navier-Stokes equations are solved by the finite volumes method with K-ε model like turbulent model. The results show that for the disturbance valve 50% closed, the length of establishment seems to be reached at 25D downstream the E´toile where the flow gyration angle is reduced practically to zero value. But for the Tee disturbance the results show that the flow needs more than 25D to reach the profiles requested by the standards. An experimental study is essential to validate these results for choosing a standard disturbance which will be examined with conditioners quoted in standard 5167 and thereafter the development of a new flow conditioner.

Simulation and Experimental Study of Wavefront Measurement Accuracy of the Pencil-Beam Method

2016 ◽  
Vol 29 (4) ◽  
pp. 32-36 ◽  
Author(s):  
Takumi Goto ◽  
Satoshi Matsuyama ◽  
Hiroki Nakamori ◽  
Yasuhisa Sano ◽  
Yoshiki Kohmura ◽  
...  
Keyword(s):  
Experimental Study ◽  
Measurement Accuracy ◽  
Pencil Beam ◽  
Wavefront Measurement ◽  
Beam Method

Linear measurement accuracy of CBCT panoramic reconstructions: experimental study with dry human mandibles

2020 ◽  
Author(s):  
Viviane de Sousa Moreira Almeida ◽  
Rodrigo Tavares Bomfim ◽  
Ana Cristina Rosário Sobreira ◽  
Inessa da Silva Barbosa ◽  
Patricia Miranda Leite-Ribeiro ◽  
...  
Keyword(s):  
Experimental Study ◽  
Measurement Accuracy ◽  
Linear Measurement
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