高温高压油气井下光纤光栅传感器的应用研究

设计并研制了耐高温、高压、防腐蚀、抗氧化和具有温度补偿功能的双光纤光栅(FBG)传感器.采用高温恒弹合金作为FBG的基底材料和耐高温、高强度的粘接胶,将压力传感FBG和温度传感FBG与基底材料封装为一体,组成温度和压力双FBG传感器.实验室标定表明,压力检测范围为0~20MPa,温度检测范围为0~315℃;压力响应灵敏...     

一种实用的光纤Bragg光栅压力传感器

设计了一种弹性圆筒为衬底的光纤Bragg光栅(FBG)压力传感头,采用参考光栅补偿温度变化对FBG测量压力的影响。在温度为20～100℃、压力为0～20MPa的范围内测试了传感器的特性,并给出了修正温度变化后压力引起波长漂移的实验曲线。结果表明,传感器压力灵敏度为-0.0127nm/MPa,其绝对值约是裸FBG压力灵敏度的4倍,实现了压力增敏。传感头采用密封设计,避免了液体和气体的渗漏,通过选择不同的内径和壁厚,可调整传感头的量程和灵敏度。     

基于反射谱带宽展宽的FBG温度补偿压强传感

利用平面圆形膜片应变调谐的特点,采用膜盒式结构,将光纤Bragg光栅(FBG)沿径向贴于平面圆形膜片,利用反射波的带宽对压强敏感而对温度不敏感的特性解调压强,成功实现了温度补偿的压强传感测量.基于光谱分析仪(OSA)的0.05 nm分辨率,实验可得到测量系统的带宽随压强变化的灵敏度为0.28 nm/MPa,压强分辨率为±0.18 MPa,压强动态测量范围可达0.0～7.2 MPa.实验结果与理论分析相符.     

新型FBG渗压传感器在隧道涌水模型中的应用

结合波纹膜片的压力敏感特性和光纤Bragg光栅(FBG)的应变传感特性,设计了一种新型的FBG渗压传感器。传感器通过拉杆式结构将波纹膜片在应力下的挠度变形转化为FBG的轴向应变,通过恒温条件下的压强标定试验,得出传感器的压强灵敏度约为20 nm/MPa,和普通光栅相比,其压强灵敏度提高了6 000多倍。对传感器探头内部的光栅进行了温度特性标定试验,通过温度补偿光栅消除外界温度对渗压测量结果的影响。将该传感器用于隧道涌水模型的开挖试验,测得模型注水过程中测点的渗压值不断增大并趋于稳定,隧道开挖过程中渗压值轻微波动,提升水位时渗压值急剧增大。     

光纤光栅温度压力同时区分测量技术研究

提出一种基于金属合金薄壁弹性圆筒双光纤Bragg光栅(FBG)温度压力同时区分测量的传感模型。将FBG1和FBG2分别沿着圆筒的轴线方向粘贴在空心段外壁上和底座实心的外壁面上。圆筒内压力和温度的变化将引起FBG1波长的变化,温度的变化引起FBG2波长的变化,通过FBG2对FBG1的温度补偿进行温度和压力的同时区分测量。在100℃内2、0 MPa压力下,实验测得传感器的压力响应灵敏度系数约为0.012 nm/MPa,温度响应灵敏度系数约为0.012 nm/℃。     

新颖的高灵敏度光纤Bragg光栅压强传感器

提出了一种新颖的基于线性膜片的光纤Bragg光栅(FBG)压强传感模型。给出了FBG反射波中心波长与压强的关系以及压强灵敏度系数的表达式。该传感器压强响应灵敏度系数的理论值为-9.50nm/MPa,实验值为-8.73nm/MPa,分别是裸FBG灵敏度系数的3166和2910倍。理论值和实验值基本吻合。该传感器有很好的线性度,并可以通过调节膜片的大小和材料的弹性模量及泊松比来调节传感器的压强响应灵敏度。     

新颖的光纤Bragg光栅压强传感器的实验研究

提出了一种基于圆柱形容器和活塞结合的光纤Bragg光栅（FBG）传感模型。将FBG粘接在基底材料上，基底材料固定在活塞和容器底部间，容器内压力的变化导致活塞移动进而带动FBG所受拉力的变化，从而实现对外界压强的检测。该传感器的压强响应灵敏度系数理论值和实验值分别为0．9200nm／MPa和0．8223nm／MPa，分别为裸FBG灵敏度系数的306和274倍。该传感器有很好的线性度，线性度为0．9998。可以改变该传感器的有关参数来调节传感器的压强灵敏度系数，实现不同压强范围的测量。     

基于逆传播神经网络的光纤布拉格光栅触觉传感

为实现机械手指的复合式触觉传感,以光纤布拉格光栅(FBG)为传感元件,将压力传感器和温度传感器封装在同一聚合物传感单元中。分析了压力传感器受目标物体温度扰动的特性,同时利用逆传播神经网络对FBG触觉传感信号进行处理,实现了对传感单元表面正向压力的准确识别。仿真与实验结果表明,该方法进一步消除了目标物体温度对应变传感器的影响,减小了应变传感器的不确定性误差,提高了压力测量结果的稳定性和测量精度,补偿后压力传感器的温度漂移率仅为1.2×10-4 nm/℃。将补偿研究应用于机械手指FBG触觉传感阵列,可以有效抑制温度对应变传感的干扰,使得柔性机械手指触滑测量系统具有更加广阔的应用前景。     

基于温度自补偿原理的光纤布拉格光栅压力传感器

本课题研究了温度自补偿对FBG压力传感器的作用。在压缩和牵拉FBG或温度变化时,FBG周期与反射率会发生变化,从而使光纤光栅中心波长相应漂移。本课题设计的FBG传感器,可以用来分析中心波长漂移与水位的对应变化关系,同时消除环境温度与结构热膨胀的影响。与通常的FBG传感器相比,该传感器的结构用来消除温度对压力测量结果的影响,实现温度的自补偿,对于解决温度和压力交叉敏感的问题具有指导性意义。本课题分析了传感原理,进行了温度和压力测试,显示出传感器性能优良,在0-500厘米的水位压力内,精度达5‰FS,分辨率1.3cm,重复性误差0.863%,线性误差0.415%.     

薄壁应变筒式光纤光栅压力传感器的研究

设计并制备了一种金属薄壁应变弹性筒式光纤光栅压力传感器,将FBG1和FBG2分别沿着轴向和周向粘贴在该结构内筒外壁上,FBG2用来测量压力,FBG1是温度补偿光栅.通过择优选取不锈钢(Cr18Ni9)材料作为基材,优化结构内筒径与内筒壁厚的比例,测得压强达到40 MPa,压力响应度达到0.033 nm/MPa,与普通的裸光纤光栅压力传感器相比较,增大了测量范嗣,提高厂响应度达11倍.实验结果表明,通过凋整传感器结构的参数,如基材和几何尺寸等,可以使该结构压力传感器满足不同的测量范围和响应度.     

Cuffless blood pressure monitoring using hydrostatic pressure changes

This paper presents a new principle for noninvasive blood pressure measurements through a modified volume-oscillometric technique that eliminates an inflatable pressure cuff, and instead takes advantage of natural hydrostatic pressure changes caused by raising and lowering the subject's arm. This new methodology provides the distinct advantage of using an absolute gauge pressure reference for measurements, and does not necessarily require additional actuation.     

Applying pressure

In transport, by land, sea or air, pressure represents a vital factor in assuring safety, economy and reliability. The author looks at the use of pressure in these applications as well as in rail networks, and fuel and power, such as oil. Calibration of pressure measuring instruments is also looked at     

Micro packaged MEMS pressure sensor for intracranial pressure measurement

This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Miniaturization is key for lumbar puncture surgery because the sensor must be small enough to allow it be placed in the reagent chamber of the lumbar puncture needle. The size of the sensor is decided by the size of the sensor chip and package. Our sensor chip is based on silicon piezoresistive effect and the size is 400 × 400 μm². It is much smaller than the reported polymer intracranial pressure sensors such as liquid crystal polymer sensors. In terms of package, the traditional dual in-line package obviously could not match the size need, the minimal size of recently reported MEMS-based intracranial pressure sensors after packaging is 10 × 10 mm². In this work, we are the first to introduce a quad flat no-lead package as the package form of piezoresistive intracranial pressure sensors, the whole size of the sensor is minimized to only 3 × 3 mm². Considering the liquid measurement environment, the sensor is gummed and waterproof performance is tested; the sensitivity of the sensor is 0.9 × 10^-2 mV/kPa.     

多晶硅应变膜压力传感器

本文研究了多晶硅应变膜压力传感器制作技术,提出了防止多晶硅应变膜变形的工艺条件,研制出了多晶硅应变膜压力传感器。这一技术简单、与IC工艺较为兼容,适合研制集成压力传感器。     

用于义齿压力分布式测量的光纤MEMS压力传感器

根据Fabry-Prot(F-P)腔的干涉原理,采用微机电系统(MEMS)工艺,研制出一种用于义齿压力检测的F-P腔光纤微型压力传感器。传感器膜片厚为6μm,膜片边长为100μm。在与义齿基托相同材料的树脂底基上,挖边长为1.2mm、深度为0.8mm平整的方形小坑,将传感器分布式埋植入底基,并用自制的施加压力的装置对传感器加压测试。用双波长方法解调干涉信号,用阵列波导光栅(AWG)复用传感器,从而实现对口腔义齿下方组织压力的分布式测量。测量结果表明,当义齿加载0～0.6MPa压力时,系统的相对反射率比值/压力可达0.020 1/MPa,测量结果具有良好的线性度,测量系统的复用能力强,且复用传感器之间没有串扰,适用于义齿对口腔下方组织压力的分布式测量。     

Designing under pressure

Despite healthy high street sales, extreme competition in consumer electronics has made risk-reduction the new design mantra. The problem is market overcrowding. PC, laptop and games console companies; camera makers; software firms; mobile phone and PDA players; telecom and broadcast service providers; as well as the traditional giants like Sony and Philips, are all jostling for market share. And generic brands-the Coca-Colas of this world-may also soon join the fray in the handheld sector as that fragments into new directions. This article discusses the actions being taken by consumer electronics companies to ensure their share of the market and reduce design risks further.     

用压力传感器测量血压实验仪器的改装

由于原有用压力传感器测量血压的实验装置陈旧、性能不足,因此对实验仪器进行了改装。介绍了原有实验仪器的原理以及改装后的实验仪器原理。采用MPX50GP半导体应变集成型压力传感器放大电路与电表组装在一起,当电表开关指向mV档时,电表为毫伏表,用来测传感器的输出电压,当开关指向kPa档时,电表为一具电子血压计。改装后的实验仪器具有体积小,重量轻,灵敏度高等特点,既提高了医学学生对物理实验的兴趣,同时又对电子血压计有了一定的理论了解。     

高性能高温压力传感器

研究了决定多晶硅压力传感器性能的两项关键技术：各向异性腐蚀硅杯和温度自补偿。通过研 究四甲基氢氧化铵（ＴＭＡＨ）腐蚀液特性，及在不同腐蚀条件下硅杯表面状况，确定了制作高质量硅杯的工艺 条件。通过优化掺杂浓度，改善了传感器的温度特性，基本上实现自补偿。测试结果表明，多晶硅压力传感器 综合精度达０．ｌ％～０．２％ＦＳ，灵敏度温度系数绝对值小于３ × １０－４／℃，有广阔的应用前景。     

Simulations for thermal warpage and pressure nonlinearity of monolithic CMOS pressure sensors

The operation function of a piezoresistive pressure sensor utilizes a voltage output to detect the magnitude of pressure. The basic design concept for monolithic pressure sensors is to fabricate a standard submicron CMOS process with appropriate modifications to integrate on-chip signal conditioning circuits with anisotropic-etched piezoresistive sensing elements. In this study, thermal stress simulations with applied pressure loadings are used to estimate the electromechanical behavior of a new monolithic sensing element concept design. The major tasks are to predict the ripple deformation of a silicon diaphragm due to the thermal residual stresses from multiple passivation layers and estimate the pressure nonlinearities on the transducer. More detailed approaches with design and performance concerns are also discussed.