- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Reduction and compensation of humidity measurement errors at cold temperatures using dual QCM humidity sensors based on graphene oxides
摘要： One of the difficulties in measurements of relative humidity in a variety of environments is temperature-dependence especially at cold temperatures. Here, we report on the reduction and the compensation of temperature effects on humidity measurements using dual humidity sensors based on quartz crystal microbalance (QCM). Graphene oxide film is coated on quartz crystals as a humidity sensing layer for the detection of water sorption by the change of resonance frequency. Relative humidity in a test chamber, where dual QCM humidity sensors are located, is precisely controlled using a humidity generator at the temperature range from 20 °C to ?60 °C. It is found that single QCM humidity sensors measure humidity significantly higher than reference relative humidity by the generator as temperature is lowered due to the temperature-dependent resonance of quartz crystals. In an attempt to cancel out the temperature-dependent oscillation of QCM sensors, the ratio of resonance frequencies of dual QCM humidity sensors is used. Consequently, temperature-dependent errors in humidity measurement at low temperatures are evidently reduced. For the compensation of the remaining errors in the humidity measurement by dual QCM humidity sensors, a single formula is empirically obtained. After the compensation of low temperature effects, the dual QCM humidity sensors provide the measurement capability in terms of residual errors less than 1.1%rh throughout temperatures from 20 °C to ?60 °C. This study provides a useful insight to extend the applicability of QCM-based humidity sensors to environments with cold temperatures.
关键词： Compensation,Graphene oxide,Cold temperature,Quartz crystal microbalance,Humidity measurement,Humidity sensor
更新于2025-09-23 15:23:52
-
[ASME ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems - San Francisco, California, USA (Monday 27 August 2018)] ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems - Next Gen Test-Vehicle to Simulate Thermal Load for IoT FPGA Applications
摘要： As semiconductor device feature size scales and circuit performance increases, power dissipation and thermal management are becoming very important. Attention to thermal considerations is required throughout the chip development cycle from preliminary architecture planning to deployment on customer board and beyond. This paper describes a versatile thermal test vehicle that can be used to address these requirements. We discuss the architecture and implementation of a specially designed test-vehicle chip, followed by its operation. The programmability and flexibility of this vehicle will be highlighted. In addition, we cover other usage of this vehicle which includes modelling of chip-level thermal behavior with different floorplan, simulating thermal loads in IoT FPGA applications, cross-calibrating thermal numerical simulators with measured silicon data and evaluating the thermal impact of different package form-factor / material (such as thermal interface material) and cooling solutions. The abovementioned chip was fabricated using 0.18um technology and assembled in a flip-chip package. The reminder of this evaluation system is a simple, inexpensive tester from which a software is run to program the chip and to measure the spatial & temporal temperature values. Measured thermal data from different use cases are presented in this paper.
关键词： on-chip temperature measurement,thermal management,package development,package-level thermal evaluation,on-die heating,IoT servers,on-die temperature sensing,characterization methodology,thermal evaluation tool
更新于2025-09-23 15:23:52
-
Formation of 45° Silicon (110) Surface Using Triton X- <i>n</i> Surfactants in Potassium Hydroxide for Infrared Applications
摘要： Silicon (Si) micromirrors are an integral feature for many micro-optomechanical systems (MOEMS). Such mirrors are generally wet etched in alkaline solution at elevated temperature. For 90? beam steering applications, 45? slanted Si (110) plane is the prime choice fabricated with the incorporation of tensioactive surfactants. Here, Triton-Si and Triton-hydroxide (OH?)/H2O interaction using varying hydrophilic chain length Triton (X-45, X-100 and X-405) were investigated. The surfactant concentration was varied from 0 to 1000 ppm in potassium hydroxide (KOH). Triton molecules were shown to adsorb preferentially on (110) than on (100) surface. Longer chain length Triton hampered OH? access to Si surface resulting in slower etch rate. In contrast, contact angle measurement suggested that shorter Triton interfaced better with Si surface. Later, Si wafers etched in Triton 10 ppm – KOH were examined. The measured output for (110)X-45, (110)X-100, (110)X-405 and polished Si wafer reference (Rq < 5?) mirrors were 0.58, 0.76, 0.72 and 1.25 mW, respectively. Subsequently, Si-SiO2 thin film in [HLHL]2-substrate configuration was fabricated. Broadband micromirror for use in 3.0–5.5 μm spectrum range was experimentally realized with reflected efficiency of 73%.
关键词： wet etching,optical measurement,Silicon micromirrors,Triton X-n,surface roughness,potassium hydroxide,surfactants
更新于2025-09-23 15:23:52
-
Optical coordinate measurements in automotive industry
摘要： Photogrammetry is a technique of measuring 3D coordinates using photography as the main medium of metrology. This paper describes the use of the photogrammetric system in the automotive industry for control and measuring tasks. This contactless method is suitable for industrial application, because the measuring instruments are robust and mobile, so precise measurements are possible in production conditions. Presented results of measurements show that the optical measuring systems are powerful tools for quality control, analysis and discovering of causes of faults.
关键词： photogrammetry,optical measurement,accuracy,automotive industry
更新于2025-09-23 15:23:52
-
Metrology of Nanostructures by Tomographic Mueller-Matrix Scatterometry
摘要： The development of necessary instrumentation and metrology at the nanoscale, especially fast, low-cost, and nondestructive metrology techniques, is of great significance for the realization of reliable and repeatable nanomanufacturing. In this work, we present the application of a homemade novel optical scatterometer called the tomographic Mueller-matrix scatterometer (TMS), for the measurement of photoresist gratings. The TMS adopts a dual rotating-compensator configuration and illuminates the nanostructure sequentially under test conditions by a plane wave, with varying illumination directions and records. For each illumination direction, the polarized scattered field along various directions of observation can be seen in the form of scattering Mueller matrices. That more scattering information is collected by TMS than conventional optical scatterometry ensures that it achieves better measurement sensitivity and accuracy. We also show the capability of TMS for determining both grating pitch and other structural parameters, which is incapable by current zeroth-order methods such as reflectometry- or ellipsometry-based scatterometry.
关键词： inverse scattering,ellipsometry,pitch measurement,diffraction grating,scatterometry,Mueller matrix
更新于2025-09-23 15:23:52
-
Fundamental Study on Blood Pressure Measurement by FBG Sensor
摘要： In recent years, the demands for vital sign measurement system have been increasing, such as home health care for elderly people, or self-health management for healthy people. In this study, we aimed at the development of a non-invasive wearable device to measure vital sign. We use a Fiber Bragg Grating (FBG) sensor as pulse wave sensor. A FBG sensor is the optical ?ber. Therefore, a FBG sensor has a lot of features. Its characteristics are suitable for the measurement of vital signs at all times. We ?x FBG sensors to di?erent two points of the body surface and acquired pulse wave. We calculated the systolic blood pressure by using Pulse Transit Time (PTT) which is arrival time lag of pulse wave. We have con?rmed the validity of the principle of systolic blood pressure measurement by FBG sensors.
关键词： wearable,blood pressure measurement,FBG sensor
更新于2025-09-23 15:23:52
-
Recovering distance information in spectral domain interferometry
摘要： This work evaluates the performance of the Complex Master Slave (CMS) method, that processes the spectra at the interferometer output of a spectral domain interferometry device without involving Fourier transforms (FT) after data acquisition. Reliability and performance of CMS are compared side by side with the conventional method based on FT, phase calibration with dispersion compensation (PCDC). We demonstrate that both methods provide similar results in terms of resolution and sensitivity drop-off. The mathematical operations required to produce CMS results are highly parallelizable, allowing real-time, simultaneous delivery of data from several points of different optical path differences in the interferometer, not possible via PCDC.
关键词： distance measurement,spectral domain interferometry,optical coherence tomography,dispersion compensation,phase calibration,Complex Master Slave,Fourier transforms
更新于2025-09-23 15:23:52
-
[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Accurate Determination of Radiation Patterns from Near-Field Measurements in Highly Reflective Environments
摘要： The radiation pattern of an antenna under test is determined from measurements in a highly reflective, fully metallic measurement environment similar to a reverberation chamber. The undesired influence of the reflecting walls is eliminated by processing the data obtained for a large number of frequencies and different probe locations in the chamber. The post-processing concept effectively combines temporal and spatial filtering of the measured signals in an innovative field synthesis concept. S-Band measurements show the effectiveness of the proposed processing concepts. The accuracy is comparable to anechoic measurements, however, for the cost of increased measurement and post-processing effort.
关键词： echo suppression,near-field far-field transformation,antenna measurement
更新于2025-09-23 15:23:52
-
Reconstruction of isolated moving objects with high 3D frame rate based on phase shifting profilometry
摘要： Recently, moving object reconstruction based on PSP has been attracted intensive research. The errors caused by the inner movement of PSP have been addressed successfully. However, when the object with discontinuities or isolated surface is measured and the temporal phase unwrapping method is applied, additional fringe patterns are required to unwrap the phase map. The object movement between the PSP fringe patterns and additional fringe patterns will cause unwrapping errors. This paper proposes a new method to reconstruct the moving object with discontinuous or isolated surface. The object movement is tracked and the influence on the phase map caused by the movement is analyzed. Then, the phase variation caused by the movement is obtained. The phase map of the object before movement is obtained by compensating the phase map of the object after movement based on the phase variations. Finally, the object is reconstructed by dual-frequency phase unwrapping method. A new projection strategy increasing the efficiency of the 3D frame rate is also presented in this paper. The 3D frame rate achieves half of the camera capture speed. The proposed method has high potential to be applied in industrial applications for real-time measurement of moving objects. Experiments are presented to verify the effectiveness.
关键词： Fringe analysis,Surface measurements,Phase shift.,Phase measurement
更新于2025-09-23 15:23:52
-
A review on M?+?N theory and its strategies to improve the accuracy of spectrochemical composition analysis of complex liquids
摘要： High-precision spectral analysis for complex liquid components has received much attention in recent years. However, the lack of systematic strategies of measurement and modeling notably appears when multiple internal and external factors vary—e.g., the sample parameters, instruments, and external environment. Many methods have been developed to eliminate these effects. According to the characteristics of error sources and its propagation rules, “M + N” theory integrates and classifies the internal and external factors that affect the analysis of complex liquid components into M factors and N factors systematically. “M” and “N” refers to the M components in a liquid and N interference factors, respectively, and “+” means that the spectral is a response to the interaction of M and N. In this review, “M + N” theory sums up five measurement and modeling strategies used to reduce the effect of various factors on spectral quantitative analysis of complex liquids. Finally, this review summarized the strategies used to improve the accuracy of quantitative analysis of complex liquids and discussed future research directions.
关键词： spectrochemical quantitative analysis,measurement and modeling strategies,Complex liquid,M + N theory
更新于2025-09-23 15:23:52