共查询到20条相似文献,搜索用时 31 毫秒
1.
Ji J. Cho S.T. Zhang Y. Najafi K. Wise K.D. 《Electron Devices, IEEE Transactions on》1992,39(10):2260-2267
A multiplexed ultraminiature pressure sensor designed for use in a cardiovascular catheter is described. The sensor operates from only two loads, which are shared by two sensors per catheter. The sensing chip is 350 μm wide by 1.4 mm long by 100 μm thick. CMOS readout circuitry at the sensing site converts applied pressure to a frequency variation in the supply current, which is detected at the end of the catheter by a microprocessor-controlled interface. The nominal pressure sensitivity is 2 kHz/fF about a zero-pressure output frequency of 2.7 MHz. This on-site circuitry contains two reference capacitors which allow external compensation for nonlinearity and temperature sensitivity and has an idle-state power dissipation of less than 50 μW. With the transducer sealed at ambient pressure, the device can resolve pressure variations of about 3 mmHg, while vacuum-sealed devices do considerably better and should permit <2 mmHg resolution in practical systems 相似文献
2.
为了提高光纤布喇格光栅(FBG)解调系统的稳定性和准确性,避免由于压电陶瓷的迟滞性、蠕变性以及温度变化引起的法布里-珀罗(F-P)滤波器驱动电压与透射波长不成线性的问题,采用了可调谐环形腔激光器作为扫描光源,与F-P标准具、温补参考光栅、传感光栅3个单独的通道结构相结合的FBG解调方法。通过理论分析和实验验证,选择中值滤波加滑动平均滤波的方法滤除噪声,采用基于强度阈值的频谱相关寻峰算法更加准确地找到反射谱峰值的位置。结果表明,每个通道单独分开的解调方案的波长长期稳定性可达0.4pm,温度与波长的线性度高于99.90%。该系统能够实现对温度、应变等参量的稳定性的测量。 相似文献
3.
为了解决分布式光纤温度传感器在高炉热风管现场出现的温度漂移问题,采用光源中心频率匹配法对其进行了理论推导和实验验证。通过对入射光电流与参考光电流的差值进行检测来实时调整F-P光滤波器的带宽,使滤波器允许通过的频率范围始终包含光源的中心频率,实现滤波器带宽与光源中心频率的匹配。采用频率匹配法使光纤传感器输出的Raman比与距离的曲线在不同环境温度下基本重合,传感器的线性度约为0.52%。结果表明,采用光源中心频率匹配法可减小光纤传感器的温漂,且不影响传感器的线性度。将中心频率匹配法与分布式光纤温度传感技术相结合对于实现热风管表面温度的有效测量具有一定的意义。 相似文献
4.
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 相似文献
5.
The distributed optical fiber temperature sensor system based on Raman scattering has developed rapidly since it was invented in 1970s. The optical wavelengths used in most of the distributed temperature optical fiber sensor system based on the Raman scattering are around from 840 to 1330 nm, and the system operates with multimode optical fibers. However, this wavelength range is not suitable for long-distance transmission due to the high attenuation and dispersion of the transmission optical fiber. A novel distributed optical fiber Raman temperature sensor system based on standard single-mode optical fiber is proposed. The system employs the wavelength of 1550 nm as the probe light and the standard communication optical fiber as the sensing medium to increase the sensing distance. This system mainly includes three modules: the probe light transmitting module, the light magnifying and transmission module, and the signal acquisition module. 相似文献
6.
基于F-P腔的干涉/强度调制型光纤温度传感器 总被引:6,自引:3,他引:6
介绍了一种基于非本征F P腔的干涉/强度调制型光纤温度传感器。宽谱光源发光二极管(LED)发出的光经过2×2耦合器C1 传给F P传感头,传感头返回光信号再次经过耦合器C1 及C2 后分成两路,一路直接传给光电探测器D1,另一路经过窄带滤光片再传给D2,光信号经光电转换及放大后由计算机采集处理。给出了采用不同谱宽的两路光信号进行自补偿运算和温度测量的理论模型,并简单分析了影响这一温度传感器长期稳定性的原因。实验中利用Levenberg Marquardt非线性拟合得到与理论模型符合很好的温度定标曲线。该传感器在 20~200℃量程内,温度变化最小分辨率达到0 .1℃,长期测量精度达到±0. 2℃。 相似文献
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光纤布拉格光栅和长周期光栅传感器对油气井下应力和温度的同时测量 总被引:3,自引:0,他引:3
本文报导了用光纤布拉格光栅和长周期光栅结合的传感器系统对油气井下应力和测试实现同时在线检测。实验中用一宽带半导体激光器驱动一损耗中心波长为λLP=1550nm的长周期光栅和两个反射中心波长分别为λB1=1540nm和λB3=1560nm的光纤布拉格光栅。信息处理部分采用光纤平面法-珀滤波器进行波长扫描测量。 相似文献
9.
Onoda S. Tsukamoto N. Ogino M. Yamashita K. Yumoto O. Inoue K. Komatsu Y. 《Photonics Technology Letters, IEEE》2008,20(9):688-690
A new temperature sensing system, which utilizes a thin-film bandpass filter deposited on an optical fiber end face and dual-wavelength push-pull reflectometry, is proposed. The system has the following advantages over the fiber Bragg grating sensor: it can observe the temperature in a localized small area and it gets rid of microcrack growth caused by stripping of cover coating from a fiber. The feasibility of the system has been verified by simulation. 相似文献
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SHJYongji 《半导体光子学与技术》1997,3(2):125-131
A universal spectral modulation sensor with low cost,stable,reliable and accurate performances is presented.The optical measuring device using a universal spectral modulation sensor is immune to change the intensities of the light source and light transmission due to optical fiber bending and optical fiber connector loss.The spectral modulation sensor system can detect and measure various physical parameters such as pressure,temperature,gas density,and various chemical species. 相似文献
12.
SHI Yongji 《半导体光子学与技术》1997,(2)
UniversalSpectralModulationSensors:(Ⅰ)TheoryandStructure①SHIYongji(LuoyangTechnologyColege,Luoyang471003,CHN)Abstract:Auniver... 相似文献
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《Mechatronics》2015
Background and problem: The bio-parameters such as the blood pressure, the core body temperature and the biopotential are very important clinical clues to evaluate the physiological and psychological conditions of an animal. And these bio-parameters are also important for other clinical application. However, it is difficult to get the bio-parameters of a small animal for the long term under its normal state. It is a challenge for researchers to propose a method to acquire the bio-parameters of a small animal for the long term under its normal state. Method: This paper proposes an implantable radio-telemetry system to simultaneously detect long term blood pressure, temperature and biopotential of a small animal under its normal state. This system comprises an implantable capsule, a data logger and wireless energy transmission system. Three sensors are integrated into the implantable capsule. A pressure sensor is designed to detect the blood pressure, a temperature sensor to detect the inside body temperature, two tiny soft silver wires as the third sensor to detect the biopotential. The analog outputs of the three sensors are conditioned by their respective amplifiers. The three amplified bio-parameters are digitalized by an AD7683 (a 16-bit, charge redistribution, successive approximation, PulSAR analog-to-digital converter). Microprocessor PIC16F690 reads the digital data and sends it out of the animal’s body through a wireless communication chip. A data logger can receive the data and save it with time stamps into a SD card. The data in the SD card can be processed with a computer. Curves of three bio-parameters can be used for evaluating physiological and psychological conditions of the animal. Wireless energy transmission system provides energy to the implantable capsule under the animal’s normal conditions. A 3D secondary coil of the wireless energy transmission system enables itself to receive enough energy in an arbitrary position and posture. Results: In vivo experiment results show that the implantable radio-telemetry system can detect the blood, the temperature and biopotential of a rabbit. It meets the expected requirements. 相似文献
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为了提高激光位移传感器接收系统的信噪比,往往在CCD或PSD接收器前加滤光片.但是,滤光片对接收光线的折射作用将引起测量误差,而且该误差是非线性的,对于高精度位移传感器来说,这个误差是不可忽略的.设计了一种补偿方法,实验表明该方法可行. 相似文献
15.
针对SiC高温MEMS压力传感器易受温度影响,产生零点漂移、测量误差增大等问题,设计了一种温度控制系统,根据科恩-库恩公式建立了系统的数学模型,采用参数自整定PID控制算法,克服了纯PID控制有较大超调量的缺点,实现了一个温度控制系统。利用Matlab仿真软件的Similink模块建立系统的仿真模型,通过仿真和测试验证系统满足设计要求。解决了大温度范围下压力传感器难以补偿的问题,使得压力传感器在高温环境下的应用得以实现,提高了压力传感器的稳定性。 相似文献
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Miniaturized pressure transducer intended for intravascular use 总被引:2,自引:0,他引:2
L H Lindstr?m 《IEEE transactions on bio-medical engineering》1970,17(3):207-219
A pressure transducer utilizing an electrooptical method is described. As the transducer is primarily intended for intravascular use, it has been given the form of a catheter with the pressure-sensing part at the one end and the necessary bulky components at the other end. A light guide of glass fibers inside the catheter transports light from a light source to the measuring tip. Here the pressure variations affect a movable membrane which reflects a variable amount of light into another light guide leading to a photodetector. The variations in the signal from the detector are thus proportional to the applied pressure. The main part of the paper is concerned with a theoretical investigation of the principle for transducers of this type. This analysis gives relationships between the geometry of the measuring tip, the number of glass fibers, and their distribution, material constants, and signal parameters. Using these relations, it is possible to arrive at the fundamental limitations of the method, particularly in regard to the miniaturization. Furthermore, some temperature effects which are generally neglected, are analyzed. 相似文献
18.
光纤F-P腔压力传感器在高温油井下的应用研究 总被引:1,自引:0,他引:1
针对高温、高压油井的测量环境,设计研制了基于光纤非本征型Fabry-Perot(F-P)腔的波长解调型光纤压力传感器系统.该系统采用激光熔接制作的光纤F-P传感头,具有测量动态范围大、温度敏感性小、耐高温和长期工作稳定等优点,在压强0~30 MPa范围内,系统压力测量分辨率达到0.003 MPa,温度敏感性小于0.002 MPa/℃.光纤传感头采用光纤-厚壁石英管激光熔接的无胶封装方式,解决了高温环境下的传感器高压密封和光纤保护问题. 相似文献
19.
光源色度快速测量方法探讨 总被引:1,自引:0,他引:1
为实现光源色度的快速测量,提出了一种基于三基色原理的测量方法。待测光源发出的光依次通过三基色滤光片照射到光电传感器上,光电传感器输出电流信号转化为电压信号,通过V/F转换处理,由单片机系统实现数据采集和处理,得到光源色度的三刺激值和色品坐标,从而实现光源色度的快速测量。 相似文献
20.
无论是人的身体健康,还是农作物的生长,受温度、湿度与气压的影响较大,对这些因素的精准监测显得尤为重要。论文设计并实现了一款基于单片机的多功能气压计。设计以MCS-51单片机为核心处理器,气压传感器BMP180、温湿度传感器DHT11为测量器件,实现了一个对气压、温度、湿度实时监测的系统。经实验检测,设计可以实现实时监测气压、温度、湿度三个环境因素,且拥有设计简单、方便操作、精确度高等优势,在实际生产生活中拥有一定的实用价值。 相似文献