MXene在压力传感中的研究进展

近年来,压力传感器在智能可穿戴纺织品、健康监测、电子皮肤等领域得到了广泛应用。二维纳米材料MXene的出现,为压力传感带来了全新的突破。Ti3C2Tx是压力传感领域研究最多的MXene,具有良好的机械性能、高导电性、优异的亲水性以及广泛的可修饰性,是理想的压力传感材料。因此,近些年研究者们对MXene在压力传感器中的设计和应用进行了大量探索和研究。本文总结了MXene的制备技术和抗氧化方法。同时介绍了基于MXene的微结构设计,包括气凝胶/多孔结构材料、水凝胶、柔性衬底和薄膜。该类设计有利于提高压力传感器的响应范围、灵敏度和柔韧性,促进了压力传感器的快速发展。此外,进一步探讨了MXene压力传感器的工作机制,包括压阻式、电容式、压电式、摩擦电式、电池式和纳米流体式等。MXene以其优异的特性而在各种机制的传感器中得到了广泛应用。最后,对MXene材料的合成、性质以及其在压力传感方面的机遇和挑战进行了展望。     

矿井主排水系统电气自动化控制的研究分析

本文分析了矿井排水系统设备的组成，根据排水控制的要求，并结合各种传感器（主要为水位传感器、负压传感器、压力传感器、流量传感器等）等进行自动控制方面的研究分析。     

矿用差压传感器校准方法研究

目前已有的压力相关检定规程或校准规范，均未对矿用差压传感器的信号传输误差进行评价，个别地方校准规范亦不能完全涵盖该类仪器的计量性能，文章参照现行有效的MT 393—1995《矿用差压传感器》通用技术条件和其他矿用安全仪器技术规范，选择能反映矿用差压传感器性能的基本误差、回程误差、重复性、信号传输误差、绝缘电阻作为其计量特性，提出合理、可行的校准方法，为该类仪器的量值溯源提供参考。     

压力传感器构造原理及自动控制系统设计

随着传感器技术的不断成熟以及计算机控制技术在自动控制领域的应用，由自动控制技术为主要控制的机械设备对各个行业都起到了极大的推动作用。压力传感器构造自动控制在称量配料、管道压力测试等方面的应用极大地提高了工作效率。文中就利用压力传感器构造自动控制系统的方法及其典型应用进行了简要的论述。     

场发射压力传感器的研究进展

对现有场发射压力传感器的各种结构形式和研究现状进行了综合比较；从压力测量范围、阴极发射电流强度及阴阳极对准键合等方面分析传感器的改进途径；讨论了在阴极发射体阵列上沉积纳米硅薄膜，提高器件灵敏度的设想。     

采用薄结构膜片的用于生物医学方面的高性能压阻式压力传感器

采用薄结构膜片的用于生物医学方面的高性能压阻式压力传感器Ｓ．Ｍａｒｃｏ，等１．引言高性能的硅压阻式压力传感器已广泛应用于工业环境中，然而在生物医学方面，若利用硅压阻式压力传感器进行介入性测量以直接监视被测物，则将在大小尺寸、准确度和灵敏度方面受到严格...     

碳纳米管压力传感器研究进展

碳纳米管因其独特而优异的电学、力学、热学、化学及电子特性等在很多领域上展现应用的潜力,而近年来碳纳米管在压力传感器方面的应用成为研究热点之一.本文综述了碳纳米管压力传感器的基本原理以及研究进展,并对不同类型的碳纳米管压力传感器进行了比较.     

电容式柔性压力传感器的性能优化原理及研究进展

作为可穿戴电子器件的重要分支，柔性压力传感器在人机交互、健康监测等方面具有广阔的应用前景。随着新型材料与新的器件制备策略的不断开发，柔性压力传感器的力学与电学性能不断被优化以适应不同的应用需求。相较于其他传感器，电容式柔性压力传感器具有灵敏度高、功耗低、响应快的优势。电容式柔性压力传感器的性能优化主要通过改变器件的结构参数来实现，如电极有效正对面积、电极间距、有效介电常数等。主要方法策略包括新型纳米材料的应用、新型微结构设计和新型复合材料的开发。主要优化原理有四种：（1）通过改变电极表面粗糙度来改变电极有效正对面积；（2）在电极或介电层中引入空气层以降低弹性模量；（3）在介电层中引入空气或高介电常数材料来改变有效介电常数；（4）通过复合材料在介电层中形成微电容以改变总体电容变化。在电容式柔性压力传感器的性能优化研究中存在一个共性问题，即高灵敏度与宽检测范围之间总是存在一种制约关系。在一定压力范围内，尤其是低压范围，灵敏度提升往往会使器件较易达到压缩饱和而使检测范围有限，即线性度较差。近年来，研究者们着眼于高灵敏度与宽检测范围之间的制约问题，对介电层的梯度结构设计及混合响应机制进行探索，...     

模拟信号计算电路理论设计方法

在工业自动化控制系统中,现场采集温度、湿度、压力、流量等非电物理量通过传感器捕获并转换成为模拟信号,由于传感器输出的信号强度,范围、线性度不确定性等方面的原因,对传感器输出的信号必须进行预处理,预处理实质上是对模拟信号的运算,采用模拟电子技术理论分析方法,在已知模拟信号运算关系的前提下设计满足运算关系的运算电路的问题。     

压杆应变式压力传感器在爆炸冲击波载荷测试中的应用

在容器内实施化学爆炸时，容器内壁上冲击波载荷的确定是进行爆炸容器结构动力响应分析、安全评估和工程设计的基础。获得比较准确、可靠的爆炸容器内壁上作用载荷的时间历程及分布情况，对研究结构动力响应意义重大。文章采用压杆应变式压力传感器来测量爆炸冲击波载荷，这种传感器解决了普通传感器在高频压力脉冲下频响低且容易损坏等问题。压杆应变式压力传感器为一细长弹性杆，爆炸冲击波作用在杆的一端，在杆中激发一维弹性应力波，通过测量杆上适当位置处的应变，利用一维弹性应力波理论可以计算出作用在杆端的爆炸冲击载荷。文章根据一维弹性波理论，设计了满足所需频响、上升时间、持续作用时间等参数要求的压杆应变式压力传感器，其材料为高强度钢，采用动态应变放大器和数据采集仪组成测量系统。通过实验，获得了比较完整的容器内壁上冲击波载荷曲线，测量结果的重复性和一致性很好。经分析表明，压杆应变式压力传感器能准确地测得容器内壁上冲击波荷载的幅值和比较完整的曲线，对爆炸冲击波载荷测试来说，是一种比较准确可靠的传感器。     

PVDF shock sensors: applications to polar materials and high explosives

Ferroelectric polymers (PVDF) with well-defined and precisely known electrical properties are now routinely available from commercial sources. Electrical processing with the Bauer cyclic poling method can produce individual films with well-defined remanent polarization up to 9 /spl mu/C/cm/sup 2/. These polymers provide an unusual opportunity to study the structure and physical properties of materials subjected to shock loading. The behavior of PVDF has been studied over a wide range of pressures using high-pressure shock loading and has yielded well-behaved, reproducible data up to 25 GPa in inert materials. The application of PVDF gauges for recording shock waves induced in polar materials such as Kel-F, PMMA, or in reactive materials is hampered by observations of anomalous responses due to shock-induced polarization or an electrical charge released inside a shock-compressed explosive. A solution using an appropriate electrical shielding has been identified and applied to PVDF for shock measurement studies of Kel-F, and for Hugoniot measurements of high explosives (PH). Furthermore, shock pressure profiles obtained with in situ PVDF gauges in porous HE (Formex) in a detonation regime have been achieved. Typical results of shock pressure profile versus time show a fast superpressure of a few nanoseconds followed by a pressure release down to a plateau level and then by a pressure decay. More accurate measurements are reported with electrically improved PVDF gauges as well as with 0.25 mm/sup 2/ active area PVDF gauges.     

Neue Möglichkeiten zur Grobvakuummessung in explosionsgefährdeten Bereichen

Absolut pressure gauges with fully electronic signal processing designed according to explosion protection tech nique »Intrinsic Safety« for use at hazardous locations offer many advantages at reduced cost. Capacitive pressure transducers with aluminium oxide diaphragm guarantee an optimum of corrosion resistance (especially important for chemistry applications). The absolute pressure is measured with high accuracy. Temperature‐ and long‐term drifts are minimized. The gauges do not have damageable moving parts and are insensitive to vibrations and pressure shocks. An integrated current loop interface allows automatic switch‐on and read‐out of the gauges.     

Stabilität von Hochvakuum-Meßröhren

Summary Hot filament and cold cathode ionization gauges are widely used in industry and research for pressure measurements in high and ultra high vacuum systems. Important applications are e.g. sputter and deposition systems. Since a long time it is accepted without a notice that the error of commonly used ionization gauges is typically 10% to 100%. The reason of this large error is the poor long term stability of the gauge sensitivity. If vacuum measurements must be precise and reproducible, long term stability of the vacuum gauges is the decisive issue. Only a stable gauge ensures correct control of processes. Also replacement of gauges should not produce differences in order to save time and money for new calibration. This paper reports experiments on the long term stability (several months) of widely used hot filament and cold cathode ionization gauges. Causes of timedependent instabilities are discussed. A new type of Bayard-Alpert gauge (STABIL-ION) is presented which offers a substantially improved long term stability compared to older design gauges.     

Digitale Vakuummeter mit Grafikdisplay und integriertem Datenlogger

Digital vacuum gauges speed up service calls and simplify quality assurance and maintenance tasks Battery operated compact vacuum meters are the perfect solution for monitoring pressure directly on site. Typically, they are used in service and maintenance, laboratory applications, food and packaging industry, quality assurance and process documentation. Main features, operating principles and applications of newly developed digital compact vacuum gauges are presented here.     

压电传感技术在轮轨力实时监测中的应用探讨

目前轮轨力测试传感元件大多采用应变片,但应变片存在零漂、抗干扰能力差、测试系统稳定性差的问题,不满足高速重载铁路轮轨力实时监测对传感元件的要求,针对这一情形,提出了基于压电传感技术的轮轨力实时监测方法。首先,根据轮轨相互作用的特点和轨道系统约束条件,以及压电应变传感特性,提出了轮轨垂向力和横向力测试原理。然后,实验研究了PVDF压电传感器的动态特性、抗电磁干扰、抗零漂、可重复性等性能,并与普通电阻应变片进行了对比,论证了应用压电传感技术进行轮轨力实时监测的可行性。最后通过有限元仿真计算验证了所提出的轮轨力监测原理的正确性。     

Die Kalibrierung von Wärmeleitungsvakuummetern. The Calibration of Thermal Conductivity Vacuum Gauges

In many applications in the rough and fine vacuum thermal conductivity gauges are utilized. In order to determine the accuracy of the measuring values modern quality assurance systems require a regular calibration. The calibration laboratory of the German Calibration Service (DKD) at VACUUBRAND GMBH + CO KG features calibration equipment and procedures to calibrate vacuum gauges in the pressure range from 10^‐3 to 1000 mbar. The measuring techniques and calibration procedures are explained for thermal conductivity gauges with digital readouts. Besides general information on the calibration, particularities on thermal conductivity gauges and their effects on the calibration procedure are pointed out. The meaning of measuring deviation and measuring uncertainty and the interpretation of the calibration certificate for the user are discussed.     

A new multilayer planar PVDF standard hydrophone and itsapplications

A new type of PVDF hydrophone, the multilayer planar PVDF hydrophone, is described. The hydrophone disturbs measured acoustic fields very little and has a high sensitivity. The noise-equivalent pressure of the hydrophone is 45 dB re 1 μ Pa per Hz bandwidth. The working frequency range of the hydrophone is 20 kHz~4 MHz. In the range 100 kHz~1 MHz, the hydrophone has a flat frequency response with sensitivity -205 dB ±1.5 dB (0 dB=1 V/μPa). In this range, the hydrophone has been used for five years as a standard one. Two other applications (measurements of noise spectra and ultrasonic imaging) are also reported     

Direct pneumatic pressure in a clamping technique during strain gauge bonding

A technique is described for the clamping of metallic foil strain gauges during epoxy adhesion bonding to non -porous surfaces. Following application of the uncured adhesive, the gauge is conformed to the surface using self-adhesive tape and the workpiece placed in a pressurised environment for the duration of cure. The pnematically derived clamping pressure is transmitted directly to the glue line, and is equal to the pressure within the containment vessel. Since the clamping pressure is both uniform over the strain gauge area, and readily reproducible between installations, it is possible to produce consistent gauge performance. The technique may offer time and cost advantages over classical clamping methods where gauges are installed on small, intricate, or batch components in stress analysis and transducer applications.     

Microstructured vacuum gauges and their future perspectives

New prototypes and concepts of microstructured vacuum gauges have been developed by using the fabrication technologies for micro electro mechanical systems (MEMS). The realization of such microstructured gauges requires sophisticated fabrication processes such as thin film deposition, photolithography and etching techniques. This approach of MEMS vacuum gauges is demonstrated by a few examples.Micro-Pirani gauges are based on the principle that the heat transfer between two surfaces is proportional to the number of molecules (and hence the pressure) transferring the heat, when the mean free path in the gas is larger than the distance between the surfaces. In contrast to conventional Pirani gauges with heated thin wires, in a micro-Pirani gauge the heat transfer takes place between an extremely thin heated membrane and the surrounding. The thin membrane (200-nm thick) is realized by deposition of siliconoxide/siliconnitride, photolithography and anisotropic etching of silicon wafers. Heating is performed by a meander-shaped aluminum thin film heater in the center of the membrane. This micro-Pirani gauge shows a high sensitivity in the pressure range between 10⁻⁴ and 100 mbar. By using a silicon “microbridge” with 10 μm small gap between heated membrane and surrounding, the pressure sensitivity of the chip is extended up to 1000 mbar.Similar concepts are presented and discussed with respect to the miniaturization of spinning rotor gauges. The new concept is based on the application of microfabricated disks (instead of spheres) and of electrostatic instead of magnetic driving forces. The extension of the sensitivity range for miniaturized spinning rotor gauges is also discussed.Finally, new perspectives for mechanical vacuum gauges are demonstrated. By application of micromechanical processes, very thin stress-compensated membranes can be fabricated which enable sensitive mechanical gauges even for pressures in the high vacuum range. First, experimental results with respect to these membranes are represented.     

压力表检定中数据判读及测试问题的解决

分析讨论了压力表检定中数据的设定、读取及判定,给出了压力表示值误差是否超出允许误差的快速判定方法,对压力表检定过程中耐压测试和压力表指针偏转平稳性测试中的问题进行了讨论。