一种应用于大气边界层大气湍流强度测量的系统

提出了一种用于大气边界层气象参数与温度脉动测量的系统.系统由系留飞艇提供载荷,包括4层温度脉动传感器和温度、湿度、气压传感器,通过无线传感器网络实现信号的采集与传输.     

近地层大气光学湍流自动观测系统

利用CSAT3三维超声风速仪与WXT520多功能气象传感器组成近地层光学湍流自动观测系统,使用太阳能电池供电和无线传输实现无人值守,可同时测量常规气象参数和大气折射率结构常数Cn2。系统包含一个控制中心和三个测量子站,可同时对三个测量点进行观测。通过对超声虚温进行湿度修正后得到真实温度,采用单点温度脉动法计算大气折射率结构常数Cn2,计算结果与温度脉动仪实测Cn2吻合较好。本系统可适应复杂恶劣的测量环境,性能稳定可靠,且测量子站可扩展。     

500～m激光传输路径大气光学参数遥测系统

本文介绍了500m激光传输路径上大气光学参数遥测系统。它由温度脉动传感器、气象参数传感器、单片机系统、微机及网络系统组成。该系统具有自动采集、处理、存储、实时显示等功能,可得到大气光学湍流强度、温度脉动功率谱、大气温度、湿度、风向和风速等大气光学参数的时间变化和空间分布。     

基于PCI-1002的高速数据采集

温度脉动仪是测量大气光学湍流强度折射率结构常数的重要仪器,由于温度脉动仪测量的是大气温度的快速起伏变化,在进行温度脉动仪标定时,对温度脉动信号进行准确高效的采集是确保标定实验成功的前提。针对双通道风洞式温度脉动仪标定系统编写了基于PCI-1002 高速采集卡的多通道数据采集软件,应用成熟的GUI框架MFC,结合Windows系统下的高精度定时器,对不同通道下的温度脉动信号进行了实时采集,并实现了数据的实时显示、存储和初步计算。实验结果表明该数据采集系统可以方便地完成信号采集、处理、存储和显示,从而为后续的标定实验提供可靠的数据支持。     

一种光纤温度传感器的研究

本文提出了一种可用于航空发动机进口温度测量的光纤传感系统，这种双光纤传感器是通过检测光偏振态的变化来测量温度特性的。以蓝宝石单晶片作为探头的敏感元件，可耐２０００℃以上的高温。并且利用蓝宝石晶体的双折射特性得到关于温度的信息，本文从物理模型和数学分析上证实了这种传感器的可行性，用光纤传感器代替传统的发动起进口温度测量系统,可以促进全权数字式电子探测系统再新一代航空发动机中的应用.     

基于双通道恒温风洞的温度脉动仪检测系统

介绍了双通道恒温风洞检测系统的设计和性能。该系统的双通道恒温风洞有温度、风速稳定,可控温差可调等优点,通过实验检验了风洞的性能,风洞内部定点温度脉动标准差(最大处0.025℃)比室内脉动(0.059℃)小,风洞内横向温度场不完全一致,有一定的温度分布,冷热风洞标准差分别为0.044℃、0.103℃。双通道恒温风洞检测系统主要是用于对QHTP-2温度脉动仪进行各种实验操作的平台,通过风洞系统实验验证了热源照射对温度脉动仪的测量会产生辐射增温的影响,在实验条件下的增温大小为0.365℃。     

微温脉动仪系统的研究

为评价云南天文台抚仙湖太阳望远镜的圆顶视宁度,研制了一种能测量常温、微温脉动的仪器。在天文建筑物附近安放两个微温传感器,可以测量影响天文观测的湍流强度的分布情况。介绍了微温脉动仪器的工作原理,硬件设计,软件设计以及仪器的测试。测试结果表明,该微温测量结果达到了多个传感器响应时间快与同步测量要求,并且微温脉动测量达到约0.01℃的分辨率,常温测量达到0.1℃精度。     

RTD温度测量系统对ADC的要求

有多种类型的温度传感器可以用于温度测量系统。具体使用何种温度传感器,取决于所测量的温度范围和所需的精度。温度测量系统的精度取决于传感器以及传感器所接口的模数转换器(ADC)的性能。许多情况下,来自传感器的信号幅度非常小,因而需要高分辨率ADC。Σ-Δ型ADC属于高分辨率器件,适合这些系统。其     

基于光纤准直器的反射式盐度传感器

设计了一种新颖的光学盐度传感器,该传感器采用基于光纤准直器结合双通道反射原理而设计,特别适用于长距离的盐度值测量（盐度值在设计中用不同浓度的氯化钠溶液表示）。为了验证该传感器的性能,设计并实施了一个对比实验。实验系统是基于菲涅耳反射原理的双通道系统,一路通道接测量传感器,另外一路通道接普通的带保护层的光纤端子。主要创新点和先进性是:普通的光纤准直器可直接用作盐度值测量传感器,尤其是实验表明该传感器的信噪比至少比普通光纤头式传感器高6.11 dB,等价测量距离至少延长了30 km。实验同时表明温度的影响值为0.005 16 dB/℃,温度对测量值影响很小,而且该传感器系统还可以有效消除光源和外界环境带来的干扰。     

基于DS1820传感器的温度检测系统

提出了一种高智能的温度测量系统.运用数字温度传感器DS1820作为温度测量传感器,以AT89C2051单片机为核心来构成温度测量系统,给出了该温度测量系统的设计方案、硬件电路设计和软件设计,并以此实现多点温度测量.实践表明,该系统具有智能、高精度、多点温度测量和补偿功能,对温度测量具有良好的应用价值.     

Universal fiber-optic point sensor system for quasi-static absolutemeasurements of multiparameters exploiting low coherence interrogation

A universal fiber-optic high-resolution point sensor system, based upon signal recovery by dual-wavelength low coherence interferometry, has been developed and demonstrated for quasistatic absolute measurements of multiparameters. This system is capable of multiplexing up to 32 fiber-optic point sensors which can be fiber optic interferometers or fiber Bragg gratings or any combination of the two. The topology of this system is based on a spatially multiplexed scheme with low coherence signal recovery that we have reported previously. A range of multiparameter point sensors, including a medium pressure sensor, a high pressure sensor, a miniature temperature sensor, a displacement sensor, and a fiber Bragg grating strain sensor with drift-compensation, have been developed and incorporated into this network and demonstrated A range to resolution of better than 10⁴ :1 and 2×10³:1 has been achieved for the interferometric sensors and the Bragg grating strain sensor, respectively. The interchangeability of the sensors has also been demonstrated, allowing the sensors to be replaced in the event of damage. Due to the universality of the signal interrogation, the instrument can be compatible with any interferometric point sensor which has a similar optical path difference with the transmitting interferometer or any fiber grating sensor whose normal wavelength is within the spectral range of the light source. In addition, as the total sensor number which can be multiplexed is quite large, the average cost for each sensor is reduced considerably. Therefore, this system allows optical fiber sensors to compete with conventional sensors with the additional benefits of fiber-optic sensors     

Enhancement of multiplexing capability of low-coherence interferometric fiber sensor array by use of a loop topology

A novel technique for enhancing the multiplexing capability of low-coherence interferometric sensor array is proposed. The technique uses a fiber loop topology and allows for twice as many sensors as the conventional low-coherence reflectometry system to be multiplexed. Power budget and signal analyses for different sizes of sensor array are performed. A ten-sensor system was experimentally demonstrated and applied for quasi-distributed temperature measurement. An additional advantage of the technique is that it provides an extra degree of redundancy through the bidirectional interrogation of the sensor array and thus improves the system reliability.     

FBG光纤传感器的同步探测技术

光纤光栅传感解调系统的波长校准技术是人们关注的焦点,通常是将固定波长的FBG固定在恒温箱中,以此作为光纤光栅传感解调系统的参考元件．此方法占用了宽带光源的某个波长范围,从而制约了解调系统的波长扫描范围．构建的光纤光栅传感解调系统,将FP滤波器的驱动锯齿信号转变为方波信号,以此作为同步处理所需参考信号,省去了这个固定波长的FBG传感器,充分地利用了宽带光源的波长范围,并使得解调技术简单,同时提高了外接FBG传感器的数量．     

基于蓝牙技术无线通信测试系统的设计

系统是为有毒害气体报警器测试而设计。该系统能够实觋对96路传感器信号的采集,并能够监测到工作环境的温度和湿度。上位机主机采用PC机通过接习电路与蓝牙模块ROK101008相连,PC机软件采用VC＋＋6．0编程,通过串口对蓝牙模块ROK101008进行通信控制;下位机主机利用PIC16C74单片机进行湿度、湿度和气体传感器信号的采集,通过蓝牙模块与上位机进行通信。通过对系统的测试,证明利用蓝牙技术设计的无线通信测试系统能够准确地采集信号,满足工业生产测试的需要。     

Development of a dual function sensor system for measuring pressureand temperature at the tip of a single optical fiber

A dual function sensor system has been developed for measuring pressure and temperature at the tip of a single optical fiber. The sensor contains three parts: a filter band-edge shift temperature sensor, a short-wavelength-reflecting dichroic filter, and a diaphragm-based spectral modulation pressure sensor. The sensor system uses a separate and distinct light-emitting diode (LED) for interrogating each sensor, three 100/140 mm step-index fused couplers for managing light, and separate paired photodiode assemblies for analyzing the return light signal from each sensor. In bench tests, each sensor performed to specification and there was no crosstalk between sensors. This sensor design has potential catheter applications where catheter size must be kept to an absolute minimum     

光纤布喇格光栅海水温度深度检测系统研究

海水的温度、深度是其重要的物理参量,为了更安全、准确地监测海水的温度和深度,针对目前海洋温度和深度检测大都采用电信号检测,探头在水中安全性欠佳的不足,利用光纤光栅传感探头为全光学器件、水中安全可靠、易于组成传感器网络进行剖面检测的优点,提出一种基于光纤光栅的海水温度、深度检测系统,阐述了其检测原理,进行了系统及传感探头的设计和研制。结果表明,传感器温度和深度检测的线性度很好,达到0.9999,为海水温度深度检测提供了一种新途径。     

In-fiber Bragg-grating temperature sensor system for medicalapplications

A novel quasidistributed in-fiber Bragg grating (FBG) temperature sensor system has been developed for temperature proving in vivo in the human body for medical applications, e.g., hyperthermia treatment. This paper provides the operating principle of FBG temperature sensors and then the design of the sensor head. High-resolution detection of the wavelength-shifts induced by temperature changes are achieved using drift-compensated interferometric detection while the return signals from the FBG sensor array are demultiplexed with a simple monochromator which offers crosstalk-free wavelength-division-multiplexing (WDM). A “strain-free” probe is designed by enclosing the FBG sensor array in a protection sleeve. A four FBG sensor system is demonstrated and the experimental results are in good agreement with those obtained by traditional electrical thermocouple sensors. A resolution of 0.1°C and an accuracy of ±0.2°C over a temperature range of 30-60°C have been achieved, which meet established medical requirements     

Recent progress in fiber-optic extrinsic Fabry–Perot interferometric sensors

Fiber-optic extrinsic Fabry–Perot (EFPI) sensors have been successfully used for a wide range of applications. The recent progress in EFPI sensors is reviewed in this paper. First, the optical amplification technology is adopted into the EFPI sensor system to enhance the interferometric signal considerably. Second, both spatial-frequency multiplexing and coarse-wavelength-division multiplexing technologies are demonstrated for multiplexing of a modified EFPI sensor called the Fizeau sensor. Finally, the EFPI sensor is integrated with other fiber-optic sensing elements to realize the measurement of multiple parameters, for example, the EFPI is integrated with the in-fiber Bragg-grating (FBG) or the long-period-fiber-grating (LPFG) to achieve simultaneous strain and temperature measurement. Furthermore, simultaneous measurement of displacement, transverse load, static strain, temperature, and vibration can be achieved by using the combination of EFPI/FBG/LPFG.     

Highly Adaptive Transducer Interface Circuit for Multiparameter Microsystems

A reconfigurable transducer interface circuit that combines the communication and signal conditioning necessary to link a variety of sensors and actuators to a microsystem controller is reported. The adaptive readout circuitry supports high-resolution signal acquisition from capacitive, resistive, voltage and current mode sensors with programmable control of gain and offset to match sensor range and sensitivity. The chip accommodates sensor self test and self calibration and supports several power management schemes. It provides digital and analog outputs to control actuators and a standard interface to peripheral components. The 2.2times2.2 mm CMOS chip was fabricated in 0.5-mum, 3-metal, 2-poly process, dissipates ~50 muW at 3.3 V in a typical multisensor application utilizing periodic sleep mode, and can read out a wide range of sensors with high sensitivity. A prototype microsystem with a microcontroller and MEMS pressure, humidity, and temperature sensors has been implemented to characterize interface chip performance