光纤瞬变电流传感器

本文介绍了一种适用于瞬变电流测量的光纤传感器。它具有响应速度快、绝缘强度高、抗电磁干扰能力强等特点,是电力系统测量交流暂态大电流的一种潜在的具有很大实用价值的电流传感器     

新型光纤电流传感器的研制

光纤电流传感器运用Faraday效应,将光纤绕在电流母线上可以方便地测得电流母线中的电流,但光纤电流传感器的信号受环境振动、温度变化的影响严重,从而限制了其应用。本文从分析振动、温度变化的干扰机理出发,提出一种新型的在线校正方法来抑制干扰的影响,并进行了原理性实验。研究结果表明,用这种方法实现的光纤电流传感器在40～400A之间有良好的线性度和精度。     

用于测量雷电流的全光纤电流传感器

雷电流测量是研究雷电的一个重要部分。为此,本文研究了一种用于测量雷电流的全光纤电流传感器。首先,介绍了光纤电流传感器的基本原理及结构组成;其次,在实验室中对该传感器的响应速度、测量精度及测量范围等性能指标进行了测试。结果表明,该传感器的响应速度为微秒级,可测量范围在1 kA~100 kA,动态范围大于40 dB,测量误差小于5%,测量波形与标准的Pearson电流探头测试波形相比一致性较好,该研究为雷电流测量提供了一种新方法。     

反射式光纤传感器光纤对输出特性的数学模型

从反我纤传感器中最基本的光纤对入手,以光度学原理为基础,建立了该传感器在镜反射时的输出特性数学模型。在此模型的基础上,利用计算机给出了光纤传感器输出特性的仿真结果并进一步讨论了输出特性与各参数之间的关系。     

反射式光纤微位移传感器

本文主要介绍了反射式光纤微位移传感器,并搭建测试光路,完成了实验测量,确定了测试范围和测量精度。实验表明,对单模光纤,在0～62μm位移范围内,光功率变化较大;当超出该范围,光功率变化较小。对多模光纤,在0～224μm位移范围内,光功率变化比较大;当超出该范围,光功率变化缓慢。二者最小位移测量精度均可达到0．05μm。     

反射式横向位移光纤传感器特性

在实验测量的基础上形成了一种在高斯光束几何反射模型下的一维数值计算方法,可以在计算机上对反射式横向位移光纤传感器的特性进行计算分析,为该传感器的优化设计提供了一个必要工具.对用62.5/125多模光纤组成的并列反射式横向位移光纤传感器的计算分析结果表明:接收光纤端面处的反射光斑半径在180 μm附近时有最大的接收光强和最佳信噪比;反射光斑半径在180 μm～600 μm时接收光强对反射条边缘的横向位移或横向振动的动态范围、线性关系和信噪比都较佳;接收光强对反射条横向位移的分布宽度主要取决于反射条的宽度和接收光纤的芯径.     

基于数字图像识别和光纤传感器的直流大电流在线校准装置

在电解冶金和电化学工业领域,大量霍尔直流超大电流传感器无预留校准接口.针对这一实际问题,设计了一种基于数字图像识别和光纤电流传感器的直流大电流在线校准装置.该在线校准装置以光纤电流传感器为标准,利用图像传感器实时采集霍尔电流传感器二次显示仪表的示数图像,对采集到的图像进行灰度化、中值滤波、二值化、闭运算、字符分割等预处...     

一种谐振式传感器频率特性测试平台

谐振式传感器的谐振频率和Q值可以通过其频率特性计算得到,因此需要有一种通用的测试平台来测量各种不同谐振式传感器的频率特性.本文描述了一种谐振式传感器频率特性测试平台,并提出了一种采用间歇激励方法测试谐振式传感器谐振频率的新方法,采用线性调频信号激励谐振式传感器,传感器自由振动状态下的振动频率即是传感器的谐振频率;测得传感器自由振动状态下的振动频率,即可得到谐振式传感器的谐振频率.     

纳米镀金反射式甲烷气体光纤传感器的制作

根据甲烷气体在近红外的吸收光谱,研制了一种以1．65μm波段的LED作为光源、可弯曲的内径为650μm内壁纳米镀金毛细管作为气体吸收腔的甲烷气体浓度传感器,实现了对甲烷气体的实时监测,并利用差分吸收法消除了因光源不稳定对测量精确度的影响。     

Adaptive fiber-optic absolute angular position transducer optophysical measurements

A method of remote measurement of absolute angular position based on fiber optics circuitry is considered. A transducer of the angle of deviation from the vertical and of the azimuth tilt line capable of compensating in an automatic mode fluctuations in the ambient temperature and intensity of the radiation source is described. __________ Translated from Izmeritel’naya Tekhnika, No. 4, 41–45, April, 2006.     

Design of vibration-insensitive Sagnac fiber-optic current sensors using spun high-birefringence fibers

A novel fiber-optic current sensing element is proposed to enhance sensor performance using spun high-birefringence fibers. Such element includes three fiber sections. Two terminal sections with a varying spin rate along the fiber are utilized to replace the fiber quarter-wave plates, each converting the light polarization state from linear to circular and vice versa. The middle section with a uniform spin rate is utilized as the current sensing fiber that maintains the circular polarization state during the light propagation. The fiber is also wound into a special geometric structure so that the Sagnac phase shift can be inherently eliminated, and the sensing result does not depend on the position of the current conductor. The evolution of the light polarization state was analyzed using coupled-mode theory with different polarization state incidents in the sensing fiber. A sensor scheme based on this type of spun fiber is also proposed.     

全光纤电流互感器检测系统的设计

介绍了全光纤电流互感器的工作原理,分析了系统光路输出信号的特点,由此提出了基于方波调制解调的数字相关检测方案,并阐述了其测量原理及实现方法。实验结果表明,系统分辨率小于1A,系统的比例因数在-40℃-60℃下变化小于0．5％。     

The eddy current probe as a holographic transducer

Experimental work with the application of holography to eddy current imaging has previously been performed. This paper presents a theoretical analysis of the holographic imaging characteristics of the eddy current probe. A specially shaped probe design has been developed during this analysis for enhanced imaging performance. The phase multiplied holographic imaging process is explained and demonstrated. Experimental data are presented confirming the theoretical analysis and thus the eddy current probe as a viable holographic transducer.     

An eddy current transducer model for image restoration

We describe in this short paper a new imaging model for the spatial magnitude response of an absolute eddy current transducer to a flaw. This model is appropriate for image restoration purposes in that it captures the transducer response with sufficient accuracy for image restoration, yet is simple enough to be computationally practical. The model described in this paper is based on a simple resistive loop approximation to the transducer impedance changes induced by a flaw, and is efficiently implemented as layers of linear blurring functions and nonlinear point operations. The model is shown to accurately reflect the magnitude response of an absolute transducer to an EDM slot in a non-ferrous alloy. Furthermore, the model is shown to produce good restoration results for both synthetic and real images of flaws. The model may be adapted to a particular combination of absolute transducer and surface flaw type by optimizing the model parameters, either by forming the partial derivatives with respect to the parameters and minimizing by gradient descent, or by a straightforward implementation of a neural net back-propagation algorithm. Other types of eddy current transducers may be modeled by simply modifying the spatial layers to combine the local terms appropriately for the geometry of the transducer.     

Measurements of the statistical characteristics of the turbulence of an optical system with hybrid fiber-optic sensor

An optical system for diagnostics of turbulence with hybrid fiber-optic sensor is considered. The system functions in a digital mode of photographic recording of a two-dimensional accumulated optical signal directly associated with the two-dimensional probability density of turbulent fluctuations of the flow in the measurement region. From the values of the probability density, estimators of the statistical characteristics of turbulence are given in the form of digital matrices. __________ Translated from Izmeritel’naya Tekhnika, No. 9, pp. 25–29, September, 2006.     

Assurance of uniformity of measurements of spectral and dispersion characteristics in fiber-optic information transmission systems with wavelength-division multiplexing

The state and problems involved in achieving the uniformity of measurements in the field of fiber-optic information transmission systems and their components are considered. Possible approaches to the solution of these problems and the basic methods and techniques that have been developed in Russia up to this point are analyzed. __________ Translated from Izmeritel’naya Tekhnika, No. 5, pp. 30–34, May, 2006.     

A3夹心式压电超声扭转换能器的研制

本文对夹心式压电超声扭转振动换能器进行了理论及实验研究，得出了对称型扭转振动夹心换能器的共振频率设计方程，给出了频率方程式中一些主要的物理量的具体表达式。在此基础上，实际设计并制作了一个夹心扭转振动换能器，并对其所有的电声参数进行了测试     

A4负载条件下功率换能器的特性研究

本文给出３种换能器系统在有、有一定输入功率负载条件下输入电阻抗、电声效率的频率特性，在某一工作频率处的功率特性，并与线性理论结果的趋势相一致，对大功率超声换能器的应用有一定指导意义     

Frequency strain gage transducers with constant supply voltage of the measuring circuit

An analysis of existing frequency converters of the parameters of resistance transducers is presented. Particular attention is devoted to frequency strain gage transducers with constant measuring circuit supply voltage. The advantages and drawbacks of such devices are demonstrated. Variant designs of transducers that produce a decrease in the influence of different destabilizing factors are proposed. __________ Translated from Izmeritel’naya Tekhnika, No. 5, pp. 22–26, May, 2008.