Fast Measurement System Research Articles

Test-Fixture for Suspended-Strip Gap-Waveguide Technology on Ka-Band

This letter presents a Test-Fixture for a Suspended-Strip Gap-Waveguide technology that provides a fast measurement system for the prototyping stage. For this purpose, a transition from standard rectangular waveguide to this new technology has been developed. A TRL kit and a repeatability study have been made to ensure the reliability of the process, and several straightforward circuits have been manufactured and measured.

Development of Fast Scanning Microscopic XAFS Measurement System

We have developed a fast scanning microscopic X-ray absorption fine-structure (XAFS) measurement system using a 100–300 nm focused X-ray beam at the BL39XU nano-scale analysis station at SPring-8. This system provides two-dimensional XAFS images constructed from X-ray fluorescence (XRF) images measured by fast continuous 2-dimensional scanning at all XAFS measurement energies. High-quality XAFS spectra at each position were obtained by correcting shift in the XRF images. We applied our proposed method to measuring single catalyst particles, and succeeded in measuring the microscopic x-ray absorption near-edge structure (XANES) images that were 2–4 μm square with a spatial resolution of 300 nm.

2A2-P20 高速旋光測定装置の開発(非接触センシング)

2A2-P20 高速旋光測定装置の開発(非接触センシング)

137单元变形镜的性能测试及校正能力实验

A 137-element Deformable Mirror(DM) was manufactured by ourselves to carry out the research on the adaptive optics.First,a Zygo interferometer was used to test the static characteristics of the DM,which included figure tests,response tests of single actuators and coupling tests.Then,Zernike polynomial fitting and surface flattening were performed to test the correction capability of the DM,respectively,and the correction capability was also verified experimentally at an adaptive optics test-bed.Finally,a fast response measurement system was built up to test the dynamic response abilities of the DM and its drive electronics.The tests and experiments show that the surface of the DM after flatten calibration has the RMS and PV better than λ/50 and 0.18λ(λ=632.8 nm),respectively.Furthermore,the DM can fit and correct the first 7 order Zernike polynomials reasonably.The dynamic responses both of the DM and its high voltage driver are faster than 1 kHz.The tests in the indoor adaptive optics system show that the DM improves the system's Strehl ratio from less than 0.1 to better than 0.9,which enhances the imaging capability of the system greatly.

In-Process Fast Surface Measurement Using Wavelength Scanning Interferometry

A wavelength scanning interferometry system for fast areal surface measurement of micro and nano-scale surfaces which is immune to environmental noise is introduced in this paper. It can be used for surface measurement of discontinuous surface profiles by producing phase shifts without any mechanical scanning process. White light spectral scanning interferometry, together with an acousto-optic tuneable filtering technique, is used to measure both smooth surfaces and those with large step heights. An active servo control system is used to serve as a phase compensating mechanism to eliminate the effects of environmental noise. The system can be used for on-line or in-process measurement on a shop floor.

Repeatability and reproducibility study of thin film optical measurement system

Investigation on surface roughness of thin films is an important issue in manufacturing engineering because the performance of a coated film is significantly affected by the surface roughness of thin films. A fast and flexible optical measurement system to measure surface roughness of hard coatings deposited by cathodic arc evaporation is developed in this work. The objective of this work is to examine the repeatability and reproducibility (R&R) of an optical measurement system. Percentage of equipment variation, appraiser variation and R&R is 7.25%, 1.42% and 7.39%. Thin film optical measurement system developed is acceptable according to the measurement systems analysis and the R&R technique.

Automatic detection of seed coat fragments in cotton fabrics

Seed coat fragments (SCFs) reduce the marketability of cotton fiber, yarns and fabrics. It is particularly important to measure SCF content in the fabric because they cause severe dyeing and appearance defects. SCF content is greatly affected by cotton varieties, environmental conditions during crop development, and mechanical processing, but studying their effects in fabrics can be very tedious and time consuming. In this paper, we present an image analysis system for accurate and fast measurement of SCFs in greige fabrics, and the conditions of using the system for reliable and repeatable data. In the study, four different US cotton varieties were selected, and processed with regular manufacturing facilities. The relationship between sample size and precision of the image analysis system was determined through statistical analysis. It was found that the minimum sample size for each variety should consist of five camera images with a minimum of four fabric samples per variety with three replications, which gives a least significant difference (LSD) of 64.54 for dark speck count. Dark speck counts for the four fabrics tested ranged from 267.7 to 659.9. Increasing sample size will lower the LSD.

Fast and accurate shape measurement system utilizing the fringe projection method with a ferroelectric liquid-crystal-on-silicon microdisplay

Fringe projection methods using the phase-shifting technique have the advantages of fast 3-D shape measurement and high accuracy. The performance of the fringe projection system, including image quality, nonlinearity of the projected intensity, stability, and switching time for multiple phase-shifted patterns, is essential for fast and accurate shape measurement. A fast and accurate measurement system using a ferroelectric liquid-crystal-on-silicon microdisplay and a high-powered light emitting diode light source is developed. Our results indicate that the nonlinearity of the projected intensity and the stability of the fringe projection were dramatically improved compared with an ordinary commercial liquid crystal display projector. The rapid measurement of the warpage distribution of a flip chip ball grid array electronic package was performed by using the developed system. Nine phase-shifted fringe images with a resolution of 1280×960 pixels were recorded in 1.6 s. In addition, the measurement results obtained by our system agreed well with the results obtained from a micrometer and laser focus sensor. The average error was 2.6 µm, and the standard deviation was less than 10 µm with a 6-mm measurement range.

Thermal contact conductance estimation and experimental validation in hot stamping process

The variation in temperature of the blank would make major contribution to the mechanical properties of final component in hot stamping of ultra high strength steel (UHSS). It is important to use accurate thermal contact conductance (TCC) to carry out finite element simulation of hot stamping for reliable caculation results. In this paper, a flat compression test was performanced on a servo press. A fast response temperature measurement and data acquisition system was designed to obtain the temperature history of blank and die under different pressures. The thermal contact conductance between blank and die was got using an optimization algorithm. The error between the temperature curves using calculated thermal contact conductance and the curves of measurement temperature was analyzed. Result shows that reliable simulation results of temperature can be got through accurate thermal contact conductance.

Fast measurement system and super high directional resolution head-related transfer function database

Head-related transfer functions (HRTFs) describe the acoustical transmission process from a point sound source to two ears in the free field. They are vital to the researches of binaural hearing and virtual auditory display. Measurement is the most important approach to obtain HRTFs, but it is time-consuming. To accurate HRTF measurement, a computer-controlling measurement system is designed. The system consists of multiple sound sources at different elevations with a finest interval of 5° and a horizontal turntable with an azimuthal resolution of 0.1°. It is able to work in non-anechoic environment and suitable for both mannequin and human subject measurement. A practical example indicates that the system allows for measuring far-field HRTFs at 493 source directions within half an hour. By using the system, a super high directional resolution HRTF database for KEMAR mannequin is established. The database includes 3889 pairs of head-related impulse responses (HRIRs, the time domain counterpart of HRTFs) at distance of 1.0 m, elevation interval of 5° (from -45° to 90° ), and azimuthal interval of 2.5°. Each HRIR is 1024-point length at 96 kHz sampling frequency and 24-bit quantization. The database is applicable to the research on binaural hearing and virtual auditory display.

A real-time velocity diagnostic for NSTX

A new system for fast measurements of the plasma toroidal velocity has been installed on the National Spherical Torus Experiment, NSTX [M. Ono et al., Nucl. Fusion 40, 557 (2000)]. The diagnostic, based on active charge-exchange recombination spectroscopy, can measure at up to six radial locations with maximum sampling rate of 5 kHz. The system is interfaced in real time with the NSTX plasma control system, in order to feed back on plasma velocity by means of actuators such as neutral beams and external coils. The paper describes the design criteria and implementation of the diagnostic. Examples from the initial tests of the system during neon glows are also discussed.

Fast surface measurement using wavelength scanning interferometry with compensation of environmental noise

We introduce a new optical interferometry system for fast areal surface measurement of microscale and nanoscale surfaces that are immune to environmental noise. Wavelength scanning interferometry together with an acousto-optic tunable filtering technique is used to measure surfaces with large step heights. An active servo control system serves as a phase-compensating mechanism to eliminate the effects of environmental noise. The system can be used for online or in-process measurement on a shop floor. Measurement results from two step height standard samples and a structured surface of a semiconductor daughterboard are presented. In comparison with standard step height specimens, the system achieved nanometer measurement accuracy. The measurement results of the semiconductor daughterboard, under mechanical disturbance, showed that the system can withstand environmental noise.

A fully opened photoacoustic resonator based system for fast response gas concentration measurements

This paper describes a fast response gas concentration measuring photoacoustic (PA) system based on a completely open cylindrical acoustic resonator. Contrary to conventional PA systems, the operation of the resonator presented here does not require the use of gas sampling unit. Thus adverse effects of adsorption/desorption processes that always occur on the walls of sampling units (longer response time and lower measurement accuracy) can be avoided completely. High sensitivity is ensured by efficient PA signal generation in resonant operation (through modulated laser excitation of a specially selected high-frequency combination acoustic mode of the resonator) and external noise suppression (through dual microphone configuration based differential detection scheme). The developed PA system was tested in water vapor concentration measurements, in which it was operated in parallel with a fast water vapor analyzer (LI-COR 840 with a response time of 0.5 s). Results of test measurements prove that the minimum detectable water vapor concentration with the proposed photoacoustic system is approximately 80 ppm and its response time is shorter than that of the reference instrument; which makes it a promising candidate for being used in highly demanding applications such eddy covariance flux measurements.

High resolution magnetostriction measurements in pulsed magnetic fields using fiber Bragg gratings

We report on a new high resolution apparatus for measuring magnetostriction suitable for use at cryogenic temperatures in pulsed high magnetic fields which we have developed at the Hochfeld-Magnetlabor Dresden. Optical fiber strain gauges based on fiber Bragg gratings are used to measure the strain in small (approximately 1 mm) samples. We describe the implementation of a fast measurement system capable of resolving strains in the order of 10(-7) with a full bandwidth of 47 kHz, and demonstrate its use on single crystal samples of GdSb and GdSi.

Fast Laser Scanning Imaging System for Surface Displacement Measurements

We present a scanning imaging system using galvanometric mirrors coupled to a heterodyne interferometric probe. This setup is dedicated to the off-plane surface displacement imaging, in particular for microelectronic devices. The use of galvanometric mirrors coupled to the heterodyne probe makes it a sensitive and fast measurement system. We present results on a microelectronic device, and we compare the performances of this system with point and CCD interferometry imaging setups.

Development of Measurement System for Facial Physical Properties with Short-Distance Lighting

In this research, the authors have developed a compact and fast measurement system for three-dimensional (3D) shape, normal vector, and bidirectional reflectance distribution function (BRDF) of a 3D object, e.g., a human face. Since the proposed system uses linear light sources and a luminous intensity distribution of these light sources, the BRDF can be measured for a short time and without large measurement space. The proposed system is evaluated by two methods whereby the authors confirmed its accuracy: by measuring sample known objects and by comparing actual and reproduced images.

Characterization of Fast Relaxation During BTI Stress in Conventional and Advanced CMOS Devices With $\hbox{HfO}_{2}/\hbox{TiN}$ Gate Stacks

We evaluate the performance of a novel fast characterization methodology for NBTI and PBTI measurements. We show that the use of a programmable PCI card in combination with linear current amplifiers provides the following means: (a) to perform short BTI stresses down to ~ 30 mus; (b) to perform fast sensing with delay times tdelay ~ 30 mus and a voltage resolution of ~ 1 mV; and (c) to use arbitrary programmable stress-and-sense sequences covering many decades in time. We used the fast PCI card-based measurement system for fast NBTI-relaxation measurements in SiON/poly-Si gate stacks, as well as for a systematic study of PBTI relaxation with HfO2/ TiN gate stacks. We show for the first time that the Vt relaxation after PBT stress in nFETS with HfO2/TiN gate stacks and the Vt relaxation after NBT stress in pFETs with SiON/poly-Si gate stacks exhibit strong similarities: We found the time dependence of both types of relaxation to exhibit to first order a log(t) dependence over seven orders of magnitude in time, suggesting that both phenomena are governed by charge removal by tunneling and that tunneling front-based modeling may be used to quantify the observations.

Detection and Measurement of Fetal Anatomies from Ultrasound Images using a Constrained Probabilistic Boosting Tree

We propose a novel method for the automatic detection and measurement of fetal anatomical structures in ultrasound images. This problem offers a myriad of challenges, including: difficulty of modeling the appearance variations of the visual object of interest, robustness to speckle noise and signal dropout, and large search space of the detection procedure. Previous solutions typically rely on the explicit encoding of prior knowledge and formulation of the problem as a perceptual grouping task solved through clustering or variational approaches. These methods are constrained by the validity of the underlying assumptions and usually are not enough to capture the complex appearances of fetal anatomies. We propose a novel system for fast automatic detection and measurement of fetal anatomies that directly exploits a large database of expert annotated fetal anatomical structures in ultrasound images. Our method learns automatically to distinguish between the appearance of the object of interest and background by training a constrained probabilistic boosting tree classifier. This system is able to produce the automatic segmentation of several fetal anatomies using the same basic detection algorithm. We show results on fully automatic measurement of biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), humerus length (HL), and crown rump length (CRL). Notice that our approach is the first in the literature to deal with the HL and CRL measurements. Extensive experiments (with clinical validation) show that our system is, on average, close to the accuracy of experts in terms of segmentation and obstetric measurements. Finally, this system runs under half second on a standard dual-core PC computer.

Electric Field-Driven Strategy for Multiplexed Detection of Protein Biomarkers Using a Disposable Reagentless Electrochemical Immunosensor Array

A fast, simple, sensitive, and low-cost method for electrochemical multianalyte immunoassay was developed by combining newly designed electric field-driven incubation with a screen-printed reagentless immunosensor array. The disposable array was prepared by immobilizing respectively horseradish peroxidase (HRP)-labeled antibodies modified gold nanoparticles in biopolymer/sol-gel modified electrodes to obtain direct electrochemical responses of HRP. Upon the formation of immunocomplexes, the responses decreased due to increasing spatial blocking and impedance. At a driving potential of 0.5 V, the incubation process could be accomplished within 2 min. Under optimal conditions, this method could simultaneously detect carbohydrate antigens 153, 125, and 199 and carcinoembryonic antigens ranging from 0.084 to 16, 0.11 to 13, and 0.16 to 15 U mL(-1) and 0.16 to 9.2 ng mL(-1) with a detection time of less than 5 min, and the detection limits corresponding to the signals of 3SD were 0.06, 0.03, and 0.10 U mL(-1) and 0.04 ng mL(-1), respectively. The disposable immunosensor array and simple detection system for fast measurement of panels of tumor markers show significant clinical value for application in cancer screening and provide great potential for convenient point-of-care testing and commercial application.

A measuring system for experimental research on the thermomechanical coupling of disc brakes

This paper deals with the introduction of a measuring system for application in research on the thermomechanical coupling of disc brakes. The first part is devoted to a description of the system for fast measurement of the brake disc surface temperature field during braking, which is the main part of the measuring system. The structure of the hardware as well as principles of evaluation of the temperature field are introduced. The second part deals with applications of the system to dynamometer testing rigs and real cars. The third part presents examples of the results. They demonstrate the applicability of the measuring system in experimental research on the behaviour of a disc brake system.