设计一种新型电容式加速度测量仪

设计了一种可测量加速度的变极板间距式的差动电容传感器的测量仪。该测量仪的核心是传感器和测量电路部分:从力学上可以看成是一个质量弹簧阻尼系统。其工作过程为传感器感受力后产生加速度,运动质量块由于惯性力而拉动弹簧产生形变,使两个电容发生变化;测量电路部分,是一差动脉宽调制电路,根据测量上述电容的变化情况,推导出加速度。该测量仪是一种便捷的利用电容测量加速度的仪器。     

市电参数测量仪的设计

为了实现市电质量监测并降低测量成本,以STC12C5A60S2微处理器为控制核心,利用电压有效值转换芯片等器件,设计了一款市电参数测量仪,对频率、电压有效值及失真度进行测量;基于测周法实现50 Hz频率的测量,通过一块电压有效值转换芯片测量总电压有效值与谐波电压有效值,实现市电电压的测量,并通过计算获得失真度值;实验结果表明,该测量仪测量精度较高,频率测量误差小于0.1%,电压有效值测量误差控制在1%以内,失真度测量误差小于5%;该测量仪结构简单、性能稳定,可应用于电能质量监测系统。     

卧式杨氏模量测量仪

针对传统杨氏模量测量仪的不足,设计了卧式杨氏模量测量仪.该仪器采用千分表直接测量金属丝伸长量,提高了测量精度.     

光学极化度测量仪的研制及弱光Stokes参数的测量

极化电子束在物理学及其相关领域应用十分广泛,要深入研究这些应用必须对电子束的极化度进行精确测量,通常测量电子束极化度的仪器有两种：Mott极化度测量仪和光学极化度测量仪。因光学极化度测量仪与Mott极化度测量仪相比有许多优点而倍受关注。文章首先阐述了光学极化度测量仪的理论基础和实验原理,然后介绍了所研制光学极化度测量仪的设计方案和物理结构,最后给出了用该光学极化度测量仪测量弱光的Stokes参数的结果。     

一种基于旋转1/4波片法的激光偏振度测量仪

为了满足光的偏振特性测量要求,设计了一套激光偏振度测量仪。该装置利用旋转1/4波片对光波进行调制,通过对调制信号进行傅里叶分析获得光源的偏振度。利用测量光功率的方式对激光偏振度测量仪的偏振度进行校准,实验结果表明,所研制的激光偏振度测量仪测量精度优于0.5%,满足高精度激光偏振度测量需求。     

光纤连接器端面几何参量自动测量仪

报道了一种高精度测量光纤连接器端面几何参量的自动测量仪。叙述了光纤连接器的端面几何参量的测量原理。由光纤连接器端面形貌和纤芯中心坐标,可以高精度得到曲率半径、顶点偏移量、端面倾斜角和光纤高度等影响连接器性能的关键端面几何参量。该仪器体积小,自动化程度高,用户界面友好,使用方便,可测量物理接触、角度式物理接触等类型的光纤连接器端面几何参量。实际测量证明,该测量仪有很好的重复测量精度。该测量仪与美国Dorc公司ZX-1 mini PMS测量仪和Norland公司NC3000测量仪相比,测量精度水平相当。该仪器样机已通过华东国家计量测试中心的测试。     

静电电荷的测量

静电测量是生产、科研中的一个重要课题,静电学是电磁学中的一个重要部分。而在电磁学实验中一般没有静电测量的实验,因此我们试制了静电电荷测量仪,进行了摩擦带电的测量和空气中电荷密度的测定,效果良好。一、静电电荷测量仪静电电荷测量仪由(?)准电容和静电电压表组成,如图1所示。由于使用了静电电子管     

基于激光平面镜反射的长度测量仪的理论设计

给出了利用小型激光器和平面镜测量长度的基本原理,测量长度及其不确定度与平面镜转动角之间的关系,并例举了有关理论计算和分析．讨论了设计长度测量仪的注意事项．该长度测量仪可用于大学、中学物理实验教学和一般的长度测量．     

便携式轮对外形检测装置数字信号处理器的实现

为了快速高精度地测量轮对轮廓的外形尺寸,开发了便携式轮对外形检测装置。该装置由便携式测量仪和计算机组成。在便携式测量仪中,利用数字信号处理器DSP,采用分模块、分资源的处理方法,以C语言程序为主和汇编语言程序为辅,实现了系统功能。给出了测量原理,并针对滚轮式外形测量的基本原理,给出了算法流程及误差补偿手段。由便携式测量仪和计算机分别给出了相应的处理结果和外形曲线。     

三坐标轮廓测量仪测量离轴非球面的数据处理

为了研究三坐标轮廓测量仪测量离轴非球面的数据处理,介绍了三坐标轮廓测量仪测量离轴非球面的原理,对除三坐标测量仪自身误差之外的误差进行了详细的分析,在此基础上建立了校正这些误差的离轴非球面数据处理模型。使用Matlab与C语言混合编程,并进行了数据模拟,对实际离轴非球面进行了测量。在对离轴非球面数据进行模拟时,面形误差PV值小于0.001μm;实际应用时,面形误差PV值约为0.245μm,利用数据处理模型得到的面形误差PV值为1.2μm,达到了三坐标轮廓测量仪本身的测量精度。结果表明,所建立的数据处理模型和处理软件是正确的。     

气溶胶单粒子粒径的实时测量方法研究

介绍了近期研制的一台实时测量大气气溶胶单粒子粒径和化学成分的仪器在如何测量气溶胶单粒子粒径方面的测量原理及特点，并结合激光解吸附电离飞行时间质谱技术，利用该仪器对木屑燃烧产生的烟气气溶胶粒子的实时测量结果. 关键词： 气溶胶粒子 空气动力学粒径测量方法 激光解吸附电离 飞行时间质谱     

用激光衍射测量群体微粒尺寸分布的计算机模拟和拟合

介绍了群体微粒激光衍射现象的原理,建立了相应的数学模型;报导了相应的计算机模拟和最小二乘法拟合结果,以确定群体微粒的尺寸分布。     

标准元素分析方法的变更及其性能的改进

本文详细地论述了标准元素分析方法的变更及其性能的改进。     

Two-axis-scanning laser Doppler vibrometer for precision engineering

Laser Doppler vibrometer (LVD) has been the most favorite instrument for precision dynamics measurement due to its non-contact, high accuracy and high resolution. However, LDV can only give the dynamic data of a particular location on the entire feature. In order to get the whole field data, a laser beam-scanning mechanism has to be implemented. Currently, motor-driven scanning mirror is used to move the measurement probe from one point to another. The mechanical vibrations of the scanning mirror will reduce the measurement accuracy. This paper introduces a novel scanning LDV optical system embodied in an acousto-optic deflector scanning mechanism. It can improve the measurement accuracy since there is no mechanical motion involved. One main advantage of this system is that it generates a laser scanning beam in parallel that is different from the beam scanning in the conventional scanning laser Doppler vibrometer (SLDV). The new system has a board scanning range. The measurement target size ranges from few tens of millimeters down to 10 μm. We have demonstrated the capability of the novel system on scanning measurements of features as big as ultra-precision cutting tool to features as tiny as AFM cantilever. We believe that the novel SLDV will find profound potential applications in the precision engineering field.     

Mobile mass spectrometer for determination of heavy metals in sea water: Numerical simulation and experimental verification

A prototype mobile mass spectrometer for direct detection of heavy metal traces in water is proposed. The instrument allows automated dosed injection of liquid samples (2.5–20.0 μl) into the lock vacuum chamber of the instrument, extraction of salts containing target components for their following introduction into the high-vacuum chamber of the instrument, and determination of the component concentrations in the initial sample by means of a portable magnetic mass spectrometer equipped with an original electron-impact ion source. Experimental testing of the spectrometer using aqueous solutions containing Zn, Fe, Cu, As, and Cd shows that the instrument can detect heavy metals in water, including salt water, at concentrations ranging from 1 mg/l to 10 μg/l. The experimental results are discussed.     

激光量热计不确定度分析

 基于激光量热平台,对ISO 11551涉及的3种弱吸收数据处理方法——指数法、脉冲法和梯度法进行了不确定度分析。从回归分析的角度对拟合参数γ和A等进行了不确定度评估,采用Matlab软件进行不确定度的计算。采用B类评定法对质量、功率等测量参数进行不确定度评估。随机选取样本进行多次测量,验证了本文不确定度评估的有效性。分析和实验表明,拟合偏差是弱吸收测量不确定度的主要来源。指数法的相对不确定度约为0.0129,脉冲法的相对不确定度约为0.0029,是最优的数据处理方法,梯度法采用的样本点过于单一,相对不确定度约为0.0961。提高量热计精度的可行途径是改进数据处理方法和提高激光功率测量精度。     

Neutrino physics with cryogenic detectors

The recent results on neutrino oscillations and the consequent need to measure the value of the neutrino mass are briefly discussed. The operating principle of cryogenic detectors working at low temperatures, where the small heat capacity allows one to record and measure the temperature increase due to the tiny energy lost by a particle in form of heat is described. An application of these detectors is the measurement, or at least an upper constraint, of the neutrino mass in β decay. This approach is complementary and can, in the future, be competitive with experiments based on the spectrometric measurement of the electron energy. The search for neutrinoless double beta decay could reach a better sensitivity on the mass if a neutrino is a Majorana particle. A large cryogenic detector, named CUORICINO, on neutrinoless double beta decay (DBD) of ¹³⁰Te already yields the best constraint on the absolute value of the Majorana neutrino mass. A much larger detector, named CUORE, for Cryogenic Underground Observatory for Rare Events, is currently under construction. With its active mass of 750 kg of natural TeO₂ it aims to reach the sensitivity in the determination of the Majorana neutrino mass suggested by the results of neutrino oscillation under the inverse hierarchy hypothesis. The problem is closely connected with what I call “the second mystery of Ettore Majorana” who suggested a particle that would violate the lepton number.     

Super-sensitivity measurement of tiny Doppler frequency shifts based on parametric amplification and squeezed vacuum state

The precision measurement of Doppler frequency shifts is of great significance for improving the precision of speed measurement. This paper proposes a precision measurement scheme of tiny Doppler shifts by a parametric amplification process and squeezed vacuum state. This scheme takes a parametric amplification process and squeezed vacuum state into a detection system, so that the measurement precision of tiny Doppler shifts can exceed the Cram′er–Rao bound of coherent light. Simultaneously, a simulation study is carried out on the theoretical basis, and the following results are obtained: for the signal light of Gaussian mode, when the amplification factor g = 1 and the squeezed factor r = 0.5, the measurement error of Doppler frequency shifts is 14.4% of the Cramer–Rao bound of the coherent light in our system. At the same time,when the local light mode and squeezed vacuum state mode are optimized, the measurement precision of this scheme can be further improved by ■ times, where n is the mode-order of the signal light.     

旧式大型工具显微镜数显化

大型工具显微镜是用途较广的精密长度计量仪器,主要用于测量螺纹中径、圆柱的直径等。目前实验室和工厂现有的仪器属50年代生产的老型号产品,用目视螺旋测微鼓上的刻度读数,人工记录和处理数据,测量时费时费工。针对大型工具显微镜数显化的问题,阐述了光栅、光电显微镜、单片机、新型传感器在数显上的应用。利用新技术和新型传感器改造老设备,使其实现数字化和智能化,以提高测量效率和测量精度。改造的结果表明,改造后的仪器测量效率大大提高,精度可提高一个数量级。     

原子荧光光谱法测定中药材中砷的不确定度评定

建立氢化物发生-原子荧光光谱法测定中药材中砷含量的不确定度评定的方法,为评价测量结果提供科学依据。检测结果的不确定度由标准物质、标准溶液的配制、校准曲线的拟合、样品定容体积、样品称样量、测量重复性及回收率等所引入的不确定度分量组成。对合成不确定度进行计算,当中药材中砷含量为0.340mg/kg时,扩展不确定度为0.012mg/kg(k=2)。