超声波物位仪在真空处理料仓检测中的应用

介绍了E+H公司非接触式单探头超声波物位检测仪在攀钢RH-MFB真空处理装置铁合金料仓中的应用,阐述了检测仪的原理、功能特点及其安装要求。实践证明该检测仪具有安装简便、维护量少、故障率低、精度高(其分辨率在±5mm内)、标定简单、安全可靠等优点,具有推广价值。     

物位测量技术的现状和展望

物位测量仪表用于连续或间隙测定容器内流体或固体物料的高度,目的在于正确地测量容器中贮藏的物料容量或重量,随时知道容器内物位的高低,对物位上、下限进行报警;连续地监视生产过程并进行调节,使物位保持在所要求的高度。根据不同的实际生产过程,对物位测量的技术指标也越来越高,通常要求:     

介绍一种智能化物位测控系统（续）

介绍一种智能化物位测控系统（续）３．智能化系列连续物位变进器智能化系列连续物位变送器主要分为两种产品：９０７０智能化物位变送器和９０８０集成型智能化物位变送器。它的主要技术特点是：内装。ＬＥＶＥＬ—ＥＡＳＥ”系统，完善的自诊断、编程功能，现场两点自动...     

物位测量综述

本文介绍了如何选用物位传感器及过程流体的测量方法。     

基于EPA通信卡的调频连续波雷达物位计设计

针对现代工业对高精度物位测量技术网络化的要求,设计了以EPA实时通信控制系统为基础,以DSP为核心的高精度调频连续波雷达物位计.将物位计接入EPA网络, 实现由以太网的实时运动控制, 采用模块化的设计思想, 为所开发的调频连续波雷达物位计设计了高速智能 EPA通信接口.该模块核心为AT91R40008 ARM7处理器, 由AX88796网卡芯片实现TCP/IP协议的解析.还介绍了物位计和EPA接口卡外围电路的实现方法,及物位计开发中要注意的一些问题.测试表明采用EPA接口卡的物位计具有低功耗和高精度等特点.     

Blind sensing [eddy current sensor]

Describes a precise and accurate noncontact measuring device based on eddy currents. It is based on the principle that when an oscillator induces an eddy current in an electrically conductive target, the circuit loses energy. It works at high speeds, is nonoptical and is impervious to variations in temperature and other ambient conditions (oil, dirt, water, electromagnetic fields etc.). Electrical runout (inhomogeneity) disturbs the propagation of the eddy currents and affects the transducer output, which in turn results in noise and degraded resolution, but this effect can be reduced by an appropriate design. The sensors are used for various measurements, including distance, thickness, deflection, position, eccentricity, shaft run-out, imbalance, lubrication gap, vibration, deformation, valve stroke, compression gap, wear, shaft oscillation, shaft elongation and centring. The sensor has frequency output distance measurement; thickness measurement; deflection measurement; position measurement; eccentricity measurement; shaft run-out measurement; imbalance measurement; lubrication gap measurement; vibration measurement; deformation measurement; valve stroke measurement; compression gap measurement; wear measurement; shaft oscillation measurement; shaft elongation measurement; centring measurement;     

单目视觉测量系统不确定度的分析

基于光学测头特征点成像的单目视觉坐标测量系统是一种新兴的高精度、大尺寸、三维整体、在线测试系统,在现代工业生产中具有重要应用价值。为评价这种单目视觉测量系统的测量精度,对基于测量不确定度的评定方法进行研究。在对影响单目视觉坐标测量系统测量精度的主要因素进行深入分析研究的基础上,建立测量不确定度评定表达式,实现对测量系统测量精度的评定;通过测量试验对评定方法加以验证,试验证明测量系统的测量精度与分析结果相吻合。     

Multiple Measurement Models of Articulated Arm Coordinate Measuring Machines

The existing articulated arm coordinate measuring machines(AACMM) with one measurement model are easy to cause low measurement accuracy because the whole sampling space is much bigger than the result in the unstable calibration parameters. To compensate for the deficiency of one measurement model, the multiple measurement models are built by the Denavit-Hartenberg's notation, the homemade standard rod components are used as a calibration tool and the Levenberg-Marquardt calibration algorithm is applied to solve the structural parameters in the measurement models. During the tests of multiple measurement models, the sample areas are selected in two situations. It is found that the measurement errors' sigma value(0.083 4 mm) dealt with one measurement model is nearly two times larger than that of the multiple measurement models(0.043 1 mm) in the same sample area. While in the different sample area, the measurement errors' sigma value(0.054 0 mm) dealt with the multiple measurement models is about 40% of one measurement model(0.137 3 mm). The preliminary results suggest that the measurement accuracy of AACMM dealt with multiple measurement models is superior to the accuracy of the existing machine with one measurement model. This paper proposes the multiple measurement models to improve the measurement accuracy of AACMM without increasing any hardware cost.     

Flow measurement system model with distributed resources

The paper describes a general flow measurement system model with distributed resources based on Distributed Component Object Model (DCOM). Complex flow-rate calculation procedures are decomposed and distributed throughout the measurement system. The paper explains to what extent a flow measurement process can be partitioned into the services that can be realized as separate objects shareable across the network. Certain measurement system components perform local measurements and/or calculations and communicate with a remote measurement system resource via intranet/internet. The measurement system comprises direct measurements of the primary measurement quantities, the calculation of the flow-rate and the calculation of the physical properties for various gases, gas mixtures, water and steam. Using DCOM the measurement system automatically activates the remote client/server components that carry out flow-rate calculations in real time. The measurement system covers different measurement procedures and a variety of primary elements. The performances of the measurement system model have been verified by realizing a measurement system with two measuring sections.     

基于光纤位移传感器的轴承最小油膜厚度的测量方法

基于光纤传感器的优点和间接测量油膜厚度方法的实用性,从理论上探讨了用光纤位移传感器间接测量圆轴承润滑油膜最小厚度的两种方法:两点测量法和三点测量法。通过对测量方案设计以及误差理论分析,结果表明:两点测量方法的理论测试精度较高,其最小厚度的绝对误差和位置角的绝对误差都较小,适合测试精度要求不高的场合;三点测量方法的理论测试精度比两点测量方法高,其相应各参数的测量误差为零。     

阻尼材料动态性能参数的宽频带测试研究

针对阻尼材料动态性能参数测试难题,本文在深入分析材料测试理论的基础上,结合小试件阻尼测试研究成果,设计了一套高性价比材料参数测试系统。实验结果表明该系统测量频带宽、精度高且具有良好的可重复性。     

Intelligent measurement — A view of the state of the art and current trends

The paper examines briefly the state of the art of intelligent measurement on the basis of the proceedings of the IMEKO 1986 Symposium on the subject. It identifies advances in computer-assisted measurement, data conditioning, measurement process control, measurement result output, and measurement data processing as well as application of machine intelligence to measurement interpretation and use in decision support. It identifies the latter as a significant area of future progress. Applications of intelligent measurement in laboratory automation, electrical measurement, mechanical manufacture and associated inspection and clinical medicine are highlighted.     

激光跟踪仪测角误差的现场评价

激光跟踪仪是基于角度传感和测长技术相结合的球坐标测量系统,其长度测量采用激光干涉测长方法,可直接溯源至激光波长,因此,激光跟踪仪的长度测量精度远高于角度测量精度,相对而言,测角误差就成为评价跟踪仪测量精度的重要指标。为了对现场测量激光跟踪仪的测角误差进行快速有效地评价,采用跟踪仪多站位对空间中测量区域内若干个被测点进行测量,与传统基于角度交汇原理的多站位冗余测量不同,利用各站位所观测的高精度测长值建立误差方程,并通过测长方向的矢量位移对跟踪仪测长误差进行约束,获得被测点三维坐标在跟踪仪水平角和垂直角方向上的改正值,以此来评价激光跟踪仪的测角误差。通过Leica激光跟踪仪AT901-LR进行了多站位测角误差评价实验,在现场测量条件下,跟踪仪水平和垂直方向测角误差约为0.003 mm/m(1σ),符合跟踪仪的测量误差特性。     

微机电系统（MEMS）促进测量学发展

本文从纳米、超微角位移测量、及力学、声学、医学测量诸方面说明MEMS促进测量学的发展。通过所举范例,可以看出MEMS在各方面促进测量学发展及其深远的科学意义。其中超微角位移测量的构想以往资料未见,是创新。     

基于三坐标测量和在线测量的白车身尺寸控制

通过对三坐标测量设备和在线测量设备的特点介绍以及白车身尺寸控制的需求分析,并结合近年来在车身现场的研究及应用,从测量系统报警、测点设置、三坐标测量频次优化、数据分析过程和尺寸系统评价等方面探讨如何用三坐标测量系统和在线测量系统进行白车身尺寸的控制.