光纤声传感器综述

光纤声传感器是一种利用光纤作为传光介质或探测单元的一类声传感器,相比传统电声传感器其具有灵敏度高、频带响应宽、抗电磁干扰等优越特性,可广泛应用于国防安全、工业无损检测、医疗诊断及消费电子等领域。按照声场与光的耦合方式,把光纤声传感器分为间接耦合型和直接耦合型两种,其中,间接耦合型光纤声传感器受声耦合材料频响特性限制,存在频响不平坦、带宽较窄及动态范围小等缺点;而直接耦合型光纤声传感器克服了上述的缺点,具有广阔的发展潜力。

     

光纤声传感器的实验系统研究

针对光纤声传感器元件尺寸小、对探测灵敏度要求高的特点,本文提出了一套用于该传感器在线数据采集、灵敏度分析与调节定位的实验系统.通过分析不同工作距离下系统的接收光强度,得到了系统的灵敏度特性,并输出反馈信号控制光纤微调架自动、精确的调节到最佳工作距离,以使传感器获得最佳的探测灵敏度.采用该系统对平行结构的光纤声传感器进行了实验研究,实验结果表明传感器的最佳工作距离为160 μm,对声音的探测灵敏度为16 mV/Pa.     

静压式光纤光栅密度传感器研究

一、前言密度传感器在工业生产控制、检测、航天、军事等方面应用非常广泛,它是确定液体密度或者液体密度函数其他参数的一种计量仪器。传统的玻璃密度计不但不能实时监测储油罐内的密度变化,而且手动操作,人工读数,不可避免地存在易受人为因素影响的缺点,不能实现测量自动化。比重也称相对密度,固体和液体的比重是该物质的密度与在标准大气压、     

调制式光纤甲烷气体传感器的研究

利用Fabry-Perot腔的选频特性,考虑与光纤的低损耗窗口相一致和价格等因素,以价廉的1300nm波段的LED作为光源,实现了PZT对Fabry-Perot腔的正弦调制;对甲烷气体浓度进行谐波检测,检测灵敏度可达10ppm。研究表明,该传感器灵敏度和稳定性大大提高。     

双孔悬臂梁式称重传感器固定方式的改进

称重传感器在电子称重系统中起着举足轻重的作用,其准确度、稳定性受许多因素的影响。本文叙述了双孔悬臂梁式称重传感器固定方式的改进措施,并结合一组试验数据,证明了固定方式是影响称重传感器性能指标的因素之一。     

光闸式光纤位移传感器

本文介绍了一种强度调制型光纤传感器-光闸式光纤位移传感器,推导出其调制函数关系式.通过实验表明,与传统的位移传感器相比,其具有精度高、重复性好、无滞后性等优点.引进了均匀光斑装置后能提高工作区域范围,该善线性度.增加了参考通道后有效地减小了光源波动及光纤抖动等干扰信号的影响,更加有利于其在工程中的实际应用.     

光子晶体光纤F-P干涉式高温传感器研究

本文提出一种用于高温测量的光子晶体光纤F-P干涉传感器,通过熔接机放电使无截止单模光子晶体光纤(ESM-PCF)一个端面完全塌陷,然后再将其与单模光纤(SMF-28e)熔接起来,最后按照设计长度切断ESM-PCF。由于在熔接点处ESM-PCF完全塌陷使其模场直径扩大,减小了与SMF-28e的模场失配损耗,并提高了熔接面的反射光强。这种方式制作简单,相对于以往的光子晶体光纤F-P干涉传感器具有更高的干涉光强度。实验结果表明,该传感器测量温度可达1100℃,温度灵敏度为29.4nm/℃,可以预见这种结构稳定、线性度好的全光纤传感器在机械、航空、冶金领域等具有一定的潜在应用价值。     

互编织式光纤管道形变传感器

设计了一种基于光纤微弯理论的管道形变传感器。它不需外加变形装置,而仅由两根光纤相互编织形成微弯,实现对形变的传感功能。经理论研究和数值分析表明,它可对管道变进行实时监测,具有较大的应用价值。     

有源光纤式流量传感器的研究进展

光纤式有源流量传感器是近年来发展起来的一种基于光纤传感技术、流量检测技术的新型流量传感器.目前,主要将金属薄膜的光热转换效应或电阻的热效应与光纤及光纤光栅的温度、应力特性(在流体环境下光的强度、频率、波长及相位等受温度、应力调制的特性)相结合并制得一类新型的光纤有源流量传感器,包括光纤光栅点式及光纤散射(布里渊、瑞利)分布式有源流量传感器.通过文献综述的方式来介绍有源光纤式流量传感器的工作原理、种类及其研究进展,旨在为今后研究提供方法.     

一种高灵敏度光声光纤SO2气体传感器的研究

基于气体光声效应原理，研究了一种高灵敏度光纤SO2气体浓度传感器。用染料激光器作为激励源，激励出光声信号，采用光纤位移传感器测量光声信号。设计了光学长程装置以提高光声腔的灵敏度。用此装置测量SO2气体浓度，给出了实验数据并对结果作了分析。     

A Recirculation Fiber-Optic Temperature Sensor

Methods of increasing the accuracy of measurements made with recirculation fiber-optic temperature sensors are considered. It is shown that such data-measuring systems, while possessing all the advantages of amplitude sensors (simplicity, reliability, cheapness, etc.), have high sensitivity and, as regards their metrological characteristics, at the present time can be as good as the most accurate interferometric-type phase fiber-optic sensors.     

A Fiber-Optic pH Sensor for Microbioreactors

Technical Physics Letters - A fiber-optic sensor for microbioreactors has been developed and manufactured that records pH changes in the range from 6.5 to 9 with an accuracy of ±0.2 for small...     

Fiber-Optic Polarization Pressure Sensor

The highly sensitive polarization pressure sensor is based on single-mode fiber-optic waveguides. The measured sensitivity has been found experimentally to be 13·10_–2 dB·Pa_–1·m_–1. A /4 phase plate was used as an optical decoupler in the sensor.     

Hydrostatic Fiber-Optic Liquid Level Sensor with a Position-Sensitive Detector

Measurement Techniques - Monitoring of the level of different flammable liquids is examined, including that of petroleum products in high capacity tanks, as well as during pumping, at oil storage...     

智能化光纤压力传感器

介绍了一种根据光纤弯曲损耗原理，以中空螺旋形光纤环作为压力传感元件，用８０９８单片机进行控制和数据处理的智能化光纤压力传感器。其测压范围可通过选用不同刚度的弹性元件加以扩大或缩小，测压准确度为０．５％，重复性、非线性误差均小于０．５％。     

一种新型光纤电流传感器的设计

本文提出了一种新型的高压电流光纤传感器 ,该系统由具有相位压缩原理的Sagnac干涉仪光路构成 ,与通常的干涉仪相比该系统的动态测量范围扩大数百倍 ,而且系统不受外界缓变量的影响 ,系统采用相位切换技术使干涉仪保持在正交干涉状态     

A Novel Fiber-Optic Tapered Long-Period Grating Sensor for Pressure Monitoring

The method and the required installations for fabricating tapered long-period fiber gratings can be simpler than that of standard fiber Bragg gratings, and the fabrication process is faster. To our knowledge, the tapered long-period fiber grating pressure sensor is presented here for the first time. In this paper, the fabrication method for tapered long-period fiber gratings, the sensing principle, the sensor structure, the measurement setup, and the preliminary results are presented and discussed. The pressure sensitivity of the sensor is as high as 5.1 pm/bar.     

Fiber-Optic Magnetostriction Sensor for Free Oxygen Concentration

A simple design is suggested for a free oxygen sensor capable of recording free oxygen concentration at the level of about 10²² m^–3 with a predicted linear measurement range of four to five orders of magnitude.     

Distributed Fiber-Optic Sensor for Dynamic Strain Measurement

A novel Brillouin-based distributed sensing technique is presented that can obtain the strain profile of the entire sensing fiber with a single optical pulse. Experimentally obtained spectra show that this comb excited pump signal is capable of strain and temperature measurement in a dynamic system. The results show the expected sinusoidal strain profile for a 12 s periodic strain cycle applied to the test fiber. The strain distribution for the entire fiber was obtained in 256 mus , thereby demonstrating for the first time, the potential to measure dynamic strains up to 3.9 kHz with 12 m resolution. Increased acquisition speed comes at the expense of achievable spatial resolution.