STUDY ON AUTOMATIC IN-LINE MEASUREMENT OF FeO CONTENT IN AGGLOMERATE

In this paper, the mechanism of physical method for measuring the FeO content in agglomerate replacing the chemical method is proposed after studying the electromagnetic property of the agglomerate. The microcomputer-measuring system for FeO content is provided. Attention is also paid to introducing the working principle of the H-type compensation sensor and the processing method of the measured data. This system has been successfully applied in practice to in-line measure the FeO content.

Reconstruction of 3-D Temperature Field in Holographic Interferometry

The tomography technique is commonly used for the reconstruction of holographic interferometry. However, the current reconstruction method doesn’t consider the measurement errors which are non-avoidable in the measurement and will degrade the reconstruction quality. The factors affecting the reconstruction quality are analyzed and the distribution law of the reconstruction error with experimental errors is discussed. Finally, a method to improve the reconstruction quality—the Kalman filter method is presented.

In-line imaging measurements of particle size,velocity and concentration in a particulate two-phase flow

A novel method is developed for in-line measurements of particle size, velocity and concentration in a dilute, particulate two-phase flow based on trajectory image processing. The measurement system consists of a common industrial CCD camera, an inexpensive LED light and a telecentric lens. In this work, the image pre-processing steps include stitching, illumination correction, binarization, denoising, and the elimination of unreal and defocused particles. A top-hat transformation is found to be very effective for the binarization of images with non-uniform background illumination. Particle trajectories measured within a certain exposure time are used to directly obtain particle size and velocity. The particle concentration is calculated by using the statistics of recognized particles within the field of view. We validate our method by analyzing experiments in a gas-droplet cyclone separator. This in-line image processing method can significantly reduce the measurement cost and avoid the data inversion process involved in the light scattering method.

IN-LINE MEASUREMENT OF PARTICLE SIZE AND CONCENTRATION WITH LIGHT FLUCTUATION METHOD

This paper presents a new method for in-line and in-situ particle sizing based on the Light Fluctuation Method, including the development of a novel optical probe capable of measuring particle size and concentration in the broad range of 10~1000 microns.

Fiber in-line Fabry–Pérot interferometer for simultaneous measurement of reflective index and temperature

A fiber in-line Fabry-Perot interferometer is presented. The sensing head consists of a micro ellipsoidal air cavity and a small section of solid-core photonic crystal fiber. The reflective index （RI） and temperature can be interrogated simultaneously through a fast Fourier transform and by tracing the dip wavelength shift of the reflective spectrum. Experimental results show that the RI amplitude and wavelength sensitivities are 5.30/ RIU and 8.46 × 10-1 nm/RIU in the range from 1.34 to 1.43, and the temperature amplitude and wavelength sensitivities are 6.8 × 10-4/℃ and 2.48 × 10-3 nm/℃ in the range from 15℃ to 75℃, respectively. Easy fabrication, a simple system, and simultaneous measurement make it appropriate for aluM-parameter sensing application.

Measurement of Thermal Expansion Coefficients with Holographic Technique

A simplified mathematical model was created for measurement of thermal expansion coefficients of thinsheet materials with holographic technique. Experimental set-ups corresponding to the mathematicalmodel were designed and built for both tests above room temperature and at low temperatures. Afringe control technique was introduced for low temperature measurements to compensate rigid bodymovement. Thin sheet specimens of silicon and aluminum alloy (7075) were tested with the developedtechnique. The tested results are in good agreement with reported data and thus verify the validityof the developed technique. The thermal expansion coefficients of the tested materials ranged from2.5×10-6C-1 to 23.6×0-60C-1.

Surface shape detection methods for large radio telescopes

The surface accuracy of a radio telescope is directly related to its operational efficiency and detection sensitivity.This is crucial under high-frequency observation conditions,where surface shape errors need to be controlled to within 1/16 of the working wavelength.In addition,the primary reflector of large radio telescopes is subject to dynamic deformation,caused by factors such as gravity and thermal effects.This paper presents a method for detecting the surface shape of radio telescopes using radio interferometry techniques combined with active reflector adjustment technology.This enables accurate assessment and correction of surface errors,ensuring the electrical performance of the radio telescope.This study investigates the practical applications of high-precision measurement techniques,such as microwave holography,out-of-focus holography,and wavefront distortion methods at the Tianma 65 m radio telescope(TMRT).Furthermore,the study presents the construction method of gravity models at different elevation angles and demonstrates the efficacy of the active reflector model.The results of the measurements indicate that the application of these methods to the TMRT has led to a notable enhancement of the accuracy of the primary reflector and a substantial improvement in efficiency in the Q-band.Through a process of iterative measurements and adjustments,the surface shape error is ultimately reduced to 0.28 mm root mean square(RMS).

基于多数据融合的水电机组全息监测系统及应用

随着全息检测技术与计算机性能的发展,水电站智能化研究逐渐成为评价水电行业的重要指标。提出了融合多数据的水电站相关设备的智能化监测系统,利用数字全息轮廓测量技术扫描转换原始模型的流道特征,利用传感器采集的不同工况下的运行参数与流场特性,基于云计算技术、大数据分析方法和人工智能等技术构建高效的数据分析与处理平台,逐级学习故障特征,进行故障预警定值的挖掘。该系统涵盖在线监测、故障诊断和预警、健康评估以及数据挖掘等功能,消除了水电站运行状态难监控、故障预警难发现和调度策略难实施等痛点,可为水电站全息监测系统的智能化改造、研究和发展提供一定的参考。

液相扩散系数测定方法的近期研究进展

由于液相扩散系数的理论预测和各种估算方法还不够成熟和完善 ,因此其实验测定的方法尤其受到人们的关注和重视。本文对一些常用的液相扩散系数的测定方法进行了介绍 ;

数字全息术用于光学元件表面缺陷形貌测量

利用像面数字全息显微术对光学元件表面缺陷的三维形貌测量进行了理论及实验研究。设计并搭建了相应光路系统记录全息图,采用角谱算法数值重建物光场,通过相位修正消除了系统误差引入的波前畸变,获得了经过待测光学元件表面缺陷调制的物光相位分布,并根据建立的相位分布与表面缺陷面形的关系模型计算得到缺陷三维形貌。实验以多个划痕和麻点等常见表面缺陷作为测量对象,分别获得了它们的三维形貌,以其中一条实际宽度为35μm、深度为270nm的划痕为例,测量得到该划痕的宽度为35.21μm,平均深度为267.6nm,与真实值相比,横向测量误差为0.6%,纵向测量误差为0.9%。实验结果证实该测量方法是有效、可靠的,能够准确测量光学元件表面缺陷的三维形貌,因而有助于判断光学元件损伤程度以及分析缺陷对系统波前的影响,对保障高功率激光装置的安全正常运行有重要意义。

循环代数迭代松驰法在全息层析术测量三维温度场中的应用

本文通过计算机模拟运算并结合温度场（折射率场）的先验知识。考查了用循环代数迭代松驰法重建三维温度场时不同视角范围、视角方向和松驰系数对重建精度的影响。得出了该算法的六个特点。作为实例，计算了二个截面火焰温度场分布。

用迈克尔逊干涉仪测量全息干板膜厚度

全息干板膜的厚度是全息干板的重要参数之一。使用迈克尔逊干涉仪和白光光源对2种全息干板膜厚度进行测量,并对测量结果误差进行分析,给出了测量误差与膜厚及折射率之间的关系以及此方法的适用范围。研究结果表明:在膜厚从8μm增至41μm的过程中,测量结果的绝对误差≤2μm且变化很小,相对误差则从14.1%降到了2.2%。随着膜厚的增加,相对误差明显降低;折射率n也参与了误差传递,其值与测量误差呈类似反比关系;当n值在1.5附近时,为保证测量的准确性,所测膜厚≥40μm。最后指出,迈克尔逊干涉仪在测量全息干板膜等较厚的薄膜时,具有测量范围大,结果较准确等优点。

近场测量相控阵天线的全息成像方法

研究了一种利用近场测量技术全息成像相控阵天线口径幅相的方法。该方法是把近场测量获得的方向图函数与由单元形式及幅相分布表示的方向图函数进行比较 ,采用 FFT算法和空间域的 Fourier重构法 ,可以快速、精确地成像出相控阵天线口径的“全息图”,进而诊断出阵中单元幅相的奇异程度。通过仿真实验 ,检验了该方法的成像分辨率和精度 ,并考察了不同口径区域的成像误差对辐射方向图的影响程度 。

辅助干版微角位移调制全息法测机械变形方向

提出用辅助干版微角位移调制全息法测量物体的机械变形的方向。在测量光路系统中 ,设置了两张干版 ,一张辅助全息干版用于记录被测物体的被辅助全息干版自身微角位移调制的双曝光全息图 ;另一张全息干版用于记录被测物体的非调制双曝光干涉图。前者用于分析物体的变形方向 ,后者用于测量物体的机械变形量。文中着重阐述了机械变形方向的测量原理 ,导出了相关公式 。

傅立叶变换用于全息三维物体面形测量

介绍了将傅立叶变换用于全息三维面形测量的基本原理和实验装置。首先用全息干涉条纹替代投影条纹投影到待测物体上 ,在相位解调中 ,结合Gerchberg迭代算法对变形条纹进行处理 ,然后用汉宁窗口进行数字加权滤波。结果表明 ,该测量系统实验装置简单 ,测量精度高 ,速度快 。

微波全息测量中相关机的实现

论述了微波全息测量中相关机的理论和基于FPGA的实现以及全息测量的基本方法,重点讨论了在FPGA上实现整个系统的关键和难点部分。整个设计在保证功能实现的基础上,把节约FPGA资源放在相当重要的位置来考虑,这些技术对基于FPGA的DSP系统设计有很好的借鉴意义。最后对相关机的输出数据进行了定性分析,说明了相关机工作的正确性与可靠性。本设计已在上海佘山站正式用作全息测量。

基于线阵CCD的全息光栅位移自动测量系统的研制与开发

提出了一种新型的基于线阵CCD的全息光栅位移传感器 ,该系统利用线阵CCD分辨率高、像素均匀等特点 ,对干涉条纹的移动进行精确定位 ,全息光栅在测量过程中具有不受光源波长的影响、适用光谱范围宽等特点 ,实现了位移的自动精确测量。给出了系统误差分析及结果数据 ,经实验 ,系统稳定可靠 ,精度高。

全息干涉法在液相扩散系数测定中的应用

液相扩散系数是研究气 -液、液 -液和液 -固传质的重要物性参数 ,由于理论预测和各种估算方法还不成熟和完善 ,因此其实验测定方法尤其受到人们的关注和重视。激光全息干涉法是一种新型的现代光学测量方法 。

油井多相流动电磁全息测量数据处理

大多数现有数据处理方法未充分考虑传感器测量特点。为进一步提高油井多相流动电磁测量全息成像效果,针对电磁全息测量数据误差特点,抽象出其有异于理想数据的特征。采用对"突变"和"毛刺"个别压制与整体数据平滑处理相结合的策略,形成一种电磁全息测量数据处理混合算法。处理结果表明,相比以往方法,提出的混合算法能够更大限度还原测量数据实态,从而使得重建全息流动图像具有更高精度。

全息光栅基彩色图像光谱反射率模型

本文提出了一种检测全息光栅基图像色度信息的方法,并建立相应的光谱反射率模型。由于全息光栅基独特的光谱反射特性,当光照射到全息图像上时,反射光谱的颜色会随着观察角度的改变而改变,很难检测准确,故在印刷生产过程中,全息光栅基图像的质量控制便成为生产中的一大难题。本文根据辐射传递算法,分析全息光栅基的光学规律,推导出全息光栅基图像在空间的光谱光强分布,并通过改变测试条件,建立相关色度检测方法;最后,根据光子传播规律,建立相应光谱反射率模型,并通过实验进行了验证。