scholarly journals Non-destructive Dielectric Measurements and Calibration for Thin Materials Using Waveguide-Coaxial Adaptors

2014 ◽  
Vol 14 (1) ◽  
pp. 16-24 ◽  
Author(s):  
K. Y. You ◽  
Z. Abbas ◽  
M. F. A. Malek ◽  
E. M. Cheng
Keyword(s):  
Calibration Method ◽  
Calibration Procedure ◽  
Reflection Coefficients ◽  
Dielectric Measurements ◽  
Finite Samples ◽  
Open Standard ◽  
Rectangular Waveguides ◽  
Standard Values ◽  
Calibration Techniques ◽  
Non Destructive

Abstract This paper focuses on the calibration of apertures for rectangular waveguides using open-short-load (OSL) standards and transmission-line (TL) approaches. The reflection coefficients that were measured using both calibration techniques were compared with the coefficients acquired using the thru-reflect-line (TRL) method. In this study, analogous relationships between the results of OSL calibration and TL calibration were identified. In the OSL calibration method, the theoretical, open-standard values are calculated from quasi-static integral models. The proposed TL calibration procedure is a simple, rapid, broadband approach, and its results were validated by using the OSL calibration method and by comparing the results with the calculated integral admittance. The quasi-static integral models were used to convert the measured reflection coefficients to relative permittivities for the infinite samples and the thin, finite samples

scholarly journals Assessment of The Uncertainties of a Conceptual Hydrologic Model By Using Artificially Generated Flows

2012 ◽  
Vol 20 (4) ◽  
pp. 35-43 ◽  
Author(s):  
Peter Valent ◽  
Ján Szolgay ◽  
Carlo Riverso
Keyword(s):  
Calibration Method ◽  
Calibration Procedure ◽  
Hydrologic Model ◽  
Point Of View ◽  
Model Parameters ◽  
Calibration Data ◽  
Artificial Flow ◽  
Calibration Techniques ◽  
Hbv Model ◽  
Further Development

ABSTRACTMost of the studies that assess the performance of various calibration techniques have todeal with a certain amount of uncertainty in the calibration data. In this study we testedHBV model calibration procedures in hypothetically ideal conditions under the assumptionof no errors in the measured data. This was achieved by creating an artificial time seriesof the flows created by the HBV model using the parameters obtained from calibrating themeasured flows. The artificial flows were then used to replace the original flows in thecalibration data, which was then used for testing how calibration procedures can reproduceknown model parameters. The results showed that in performing one hundred independentcalibration runs of the HBV model, we did not manage to obtain parameters that werealmost identical to those used to create the artificial flow data without a certain degree ofuncertainty. Although the calibration procedure of the model works properly froma practical point of view, it can be regarded as a demonstration of the equifinality principle,since several parameter sets were obtained which led to equally acceptable or behaviouralrepresentations of the observed flows. The study demonstrated that this concept forassessing how uncertain hydrological predictions can be applied in the further developmentof a model or the choice of calibration method using artificially generated data.

Calibration Method for Open-Ended Coaxial Probe/Nector Network Analyzer System

1992 ◽  
Vol 269 ◽  
Author(s):  
David Blackham
Keyword(s):  
Simple Procedure ◽  
Calibration Method ◽  
Systematic Errors ◽  
Network Analyzer ◽  
First Order Correction ◽  
Semi Solid ◽  
Calibration Techniques ◽  
Solid Form ◽  
Non Destructive ◽  
Coaxial Probe

ABSTRACTThe vector network analyzer readily lends itself to a variety of techniques for measuring material properties. The open-ended coaxial probe is one technique that allows swept frequency measurements of permittivity. The open-ended coaxial probe technique requires little or no sample preparation and can make non-destructive measurements on a variety of materials. It is especially suited for materials in liquid or semi-solid form. An understanding of network analyzer calibration and the coaxial probe model provides insight into calibration techniques that minimize systematic errors. This understanding also.facilitates the extension of measurement conditions beyond normal measurement constraints leading to a simple procedure which provides a first order correction of perturbations to the systematic errors.

Minnesota Department of Transportation Case Studies for Coreless Asphalt Pavement Compaction Assessment

2020 ◽  
Vol 2674 (2) ◽  
pp. 291-301 ◽  
Author(s):  
Kyle Hoegh ◽  
Trevor Steiner ◽  
Eyoab Zegeye Teshale ◽  
Shongtao Dai
Keyword(s):  
Quality Assurance ◽  
Ground Truth ◽  
Calibration Method ◽  
Field Trials ◽  
Asphalt Pavements ◽  
Attractive Potential ◽  
Dielectric Measurements ◽  
Statistical Measures ◽  
Gyratory Compaction ◽  
Air Void

Available methods for assessing hot-mix-asphalt pavements are typically restricted to destructive methods such as coring that damage the pavement and are limited in coverage. Recently, density profiling systems (DPS) have become available with the capability of measuring asphalt compaction continuously, giving instantaneous measurements a few hundred feet behind the final roller of the freshly placed pavement. Further developments of the methods involved with DPS processing have allowed for coreless calibration by correlating dielectric measurements with asphalt specimens fabricated at variable air void contents using superpave gyratory compaction. These developments make DPS technology an attractive potential tool for quality control because of the real-time nature of the results, and quality assurance because of the ability to measure a more statistically significant amount of data as compared with current quality assurance methods such as coring. To test the viability of these recently developed methods for implementation, multiple projects were selected for field trials. Each field trial was used to assess the coreless calibration prediction by comparing with field cores where dielectric measurements were made. Ground truth core validation on each project showed the reasonableness of the coreless calibration method. The validated dielectric to air void prediction curves allowed for assessment of the tested pavements in relation to as-built characteristics, with the DPS providing the equivalent of approximately 100,000 cores per mile. Statistical measures were used to demonstrate how DPS can provide a comprehensive asphalt compaction evaluation that can be used to inform construction-related decisions and has potential as a future quality assurance tool.

THE CALIBRATION OF AN ARRAY OF ACCELEROMETERS

2011 ◽  
Vol 35 (2) ◽  
pp. 251-267 ◽  
Author(s):  
Dany Dubé ◽  
Philippe Cardou
Keyword(s):  
Angular Velocity ◽  
Rigid Body ◽  
Least Squares ◽  
Calibration Method ◽  
Calibration Procedure ◽  
Rigid Bodies ◽  
New Method ◽  
Scale Factors ◽  
Array Calibration ◽  
The One

An accelerometer-array calibration method is proposed in this paper by which we estimate not only the accelerometer offsets and scale factors, but also their sensitive directions and positions on a rigid body. These latter parameters are computed from the classical equations that describe the kinematics of rigid bodies, and by measuring the accelerometer-array displacements using a magnetic sensor. Unlike calibration schemes that were reported before, the one proposed here guarantees that the estimated accelerometer-array parameters are globally optimum in the least-squares sense. The calibration procedure is tested on OCTA, a rigid body equipped with six biaxial accelerometers. It is demonstrated that the new method significantly reduces the errors when computing the angular velocity of a rigid body from the accelerometer measurements.

Convenient Calibration Procedure for Structured Light Projection System

2013 ◽  
Vol 662 ◽  
pp. 777-780
Author(s):  
Wen Guo Li ◽  
Shao Jun Duan
Keyword(s):  
Relative Position ◽  
Structured Light ◽  
Calibration Method ◽  
Calibration Procedure ◽  
Shape Measurement ◽  
Projection System ◽  
System Calibration ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Projector Calibration

We present a convenient calibration method for structured light projection system. The proposed clibration approach can realize 3D shape measurement without projector calibration, without system calibration, without precise linear z stage to be used, the relative position between camera and projector can be arbitrary, and the only involved device is a plane board. Experiment results validated that the accuracy of the proposed approach.

Comparison of Multivariate Calibration Techniques Applied to Experimental NIR Data Sets

2000 ◽  
Vol 54 (4) ◽  
pp. 608-623 ◽  
Author(s):  
Vítézslav Centner ◽  
Jorge Verdú-Andrés ◽  
Beata Walczak ◽  
Delphine Jouan-Rimbaud ◽  
Frédéric Despagne ◽  
...  
Keyword(s):  
Near Infrared ◽  
Multivariate Calibration ◽  
Calibration Method ◽  
Heterogeneous Data ◽  
Data Sets ◽  
Calibration Data ◽  
Calibration Problem ◽  
Calibration Techniques ◽  
Selection Of ◽  
Infrared Data

The present study compares the performance of different multivariate calibration techniques applied to four near-infrared data sets when test samples are well within the calibration domain. Three types of problems are discussed: the nonlinear calibration, the calibration using heterogeneous data sets, and the calibration in the presence of irrelevant information in the set of predictors. Recommendations are derived from the comparison, which should help to guide a nonchemometrician through the selection of an appropriate calibration method for a particular type of calibration data. A flexible methodology is proposed to allow selection of an appropriate calibration technique for a given calibration problem.

Static and dynamic calibrations of constant-temperature hot-wire systems

1971 ◽  
Vol 47 (4) ◽  
pp. 765-777 ◽  
Author(s):  
A. E. Perry ◽  
G. L. Morrison
Keyword(s):  
Constant Temperature ◽  
Calibration Method ◽  
Calibration Procedure ◽  
Hot Wire ◽  
Low Frequencies ◽  
Conventional Procedure ◽  
Vortex Streets ◽  
Karman Vortex ◽  
System Frequency ◽  
Wire System

The conventional hot-wire static calibration procedure for the measurement of absolute turbulence intensities with constant-temperature hot-wire anemometers is investigated and serious errors are found. An alternative calibration procedure is developed which involves shaking the wire at low frequencies in a uniform flow. A series of tests indicate that this dynamic calibration method is more accurate and consistent than the conventional procedure.A method for verifying various calibration procedures is demonstrated. This method involves the measurement of velocity perturbations in a series of Karman vortex streets. The velocity perturbation amplitude is held fixed, but the frequency varies from one vortex street to another. This method also acts as a direct check of the hot-wire system frequency response.

Calibration of Partial Safety Factors Through the Inverse FORM Method

2007 ◽  
Author(s):  
Francisco L. Silva-Gonza´lez
Keyword(s):  
Computational Cost ◽  
Calibration Method ◽  
Structural System ◽  
Safety Factors ◽  
Suction Caisson ◽  
Design Point ◽  
Inverse Form ◽  
Partial Safety Factors ◽  
Calibration Techniques ◽  
Form Approach

A calibration method which uses the so-called inverse FORM approach is proposed. The objective is to find the design point on a hypersphere in U-space, whose radius is the target reliability index, which maximizes the response that the structural system must withstand. Once the design point is determined, the safety factors can be calculated. It is demonstrated that the computational cost of the proposed method is less than the computational cost of traditional calibration techniques. The proposed method is illustrated by means of three examples: parabolic, Eurocode and suction caisson design equations.

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