Method for Effective Calibration of Temperature Loggers with Automated Data Sampling and Evaluation

A highly automated calibration method for temperature loggers is presented. By using an automated procedure, a time- and cost-efficient calibration of temperature loggers is made possible. The method is directed at loggers that lack the function/property of direct reading from a display. This type of logger has to be connected to a computer for the setting-up of the measurement and again for collection of the measurement results. During the calibration, the loggers are offline. This method has been developed for temperature loggers from Gemini Data loggers, but the software and method could be modified to suit other types of loggers as well. Calibration is performed by comparison to a reference thermometer in liquid baths; and for loggers which have external sensors, only the sensor is normally placed in the bath. Loggers with internal sensors are protected from the liquid by placing them in an exterior plastic or metallic cover, and thereafter the entire loggers are placed in the bath. A digital thermometer measures the reference temperature of the bath and transmits it to a computer by way of Bluetooth. The developed calibration software, SPTempLogger, controls the logger software, and thus the communication protocol of the logger software does not need to be known. The previous method, with manual handling of the start and termination of every measuring sequence, evaluation of the resulting data and its corresponding uncertainty components, can be replaced by this automated method. Both the logger and reference measurement data are automatically downloaded once the logger has been connected to a computer after the calibration, and the calibration software started. The data are then evaluated automatically, and by statistical analysis of the confidence coefficient and standard deviation, the temperature plateaus that the calibration includes are identified. If a number of control parameters comply with the requirements, then the correction, resolution, and short-term stability are calculated for each calibration temperature. The calculated values are saved in a database, along with information about the instruments used during the calibration, after which calibration certificates and measurement uncertainty calculations can be generated. Up to ten loggers can be connected at the same time and are then evaluated in sequence. The paper will show that the system can correctly analyze different types of measurement sequences and what measurement uncertainties are associated with this.     

基于HSPMI的激光干涉位移校准系统的构建及实验研究

基于高稳定性平面镜干涉仪（HSPMI）构建了一套激光干涉纳米位移校准系统。描述了该系统的组成,设计了基于VME总线的数字信号处理计算机软件程序,对影响系统测量不确定度的各类误差进行了分析,得出该校准系统测量不确定度为2.93 nm。分别对系统稳定性和纳米级位移测试进行了实验,验证了构建系统的有效性和实用性。     

大气环境温度与压力传感器的自动化标定系统研究

目前大气环境传感器的测试和标定主要依赖于人工手动操作完成,测试和标定效率较低,结果准确率较差。为解决该问题,在分析大气环境传感器工作原理的基础上,搭建了一套由真空泵电机、气压控制器、高低温箱、金属密封腔、标准数字温度计、工控机、待标定大气环境传感器等部分组成的大气环境传感器硬件测试平台,并设计了大气环境自动化软件测试系统,通过工控机控制标准环境,对标准环境参数进行周期采样,自动判定稳态并记录标定所需参数,从而拟合出标定曲线。对待标定温度和压力传感器进行自动化标定测试,结果显示：温度标定的拟合相关系数为0.994 5,重复性误差为0.087%;压力标定的拟合相关系数为0.996,重复性误差为0.046%,验证了测试系统的可行性。此研究成果为大气环境传感器快速部署应用提供了有力支撑,对于推动自动化技术在大气环境参数测量领域中的应用具有重要意义。     

An automated thermocouple calibration system

An automated thermocouple calibration system (ATCS) was developed for the unattended calibration of type-K thermocouples. This system operates from room temperature to 650°C and has been used for calibration of thermocouples in an eight-zone furnace system which may employ as many as 60 thermocouples simultaneously. It is highly efficient, allowing for the calibration of large numbers of thermocouples in significantly less time than required for manual calibrations. The system consists of a personal computer, a data acquisition/control unit, and a laboratory calibration furnace. The calibration furnace is a microprocessor-controlled multipurpose temperature calibrator with an accuracy of ±0.7°C. The computer software is menu-based for flexibility and ease of use. The user needs no programming experience to operate the system     

A Frequency Modulation Based System Using Bilayer Thin-Film Displacement Sensors

A novel method has been used for accurately measuring low voltage signals (~10^-4 V) associated with inductance changes of bilayer thin-film sensors under bending stress. In this paper the architecture of the system is first presented, and then the design ideas and key technologies are followed. Initially, the frequency modulated signals were simulated with superimposed noise signals to test the demodulation performance of the written program. From the results, the expected output of the program was confirmed. Following this, the frequency modulation technique was used with actual sensor signals to measure the displacement of a bilayer thin film sensor. The results from the acquisition were compared with a previously developed amplitude modulation based setup, and it proved that the frequency modulation system provided a robust and accurate solution to evaluate magnetostrictive materials and their application in magnetic sensors     

Application of FBOLES—a prototype expert system for fault diagnosis in nuclear power plants

The basic concept of a frequency-based on-line expert system (FBOLES) approach for the on-line fault diagnoses of nuclear power plants has been previously presented in our companion papers. This paper reports on the status of the protoype software development and the real time on-line experiment results. The main steam and feedwater condensate system (MSFCS, namely, the secondary loop) of a nuclear power plant (950 MW, three loops) simulated by the Tsinghua simulator has been selected as a target system at the present stage of development. The knowledge bases for MSFCS have been initially constructed. A total of 62 signals from the simulator have been selected as the on-line evidence for diagnosis. Thirty-three fault experiments were performed in which 21 were detected accurately (only one candidate) by FBOLES immediately after the first abnormal signals were received and the other 12 were detected accurately within 0·5 to 3 min as the development of abnormality. These experiments include not only the failures of pumps, valves, pipes, etc., of MSFCS itself, but also the failures outside MSFCS. Three of them involve non-initiating events. As a software package, FBOLES can perform either the on-line diagnosis where the signals are input from the simulator directly or the off-line diagnosis that either repeats the on-line diagnosis in a selectable time scale by using the data received on-line and stored on disk or allows users to input signals from a keyboard. Also, the integrated information base, including the modular mini knowledge bases and other necessary data, can be edited and assembled by users easily and compiled by FBOLES into coded format.     

位移传感器校验装置的研制

为解决大量程位移传感器检定过程中,传统人工手动检定法操作复杂、耗时长、测量准确度低的问题,研制了大量程位移传感器自动校验装置。详细介绍了该装置的硬件组成和软件设计,并阐述其创新特色。利用该装置对LVDT位移传感器进行校准,并对其测量不确定度进行评定。试验证明,该位移传感器校验装置测量准确度高、运行稳定性好,可有效提高检定效率,能够替代人工对位移传感器进行自动化检定,具有重要技术借鉴意义。     

Optical Intensity-Based Measurement of Multipoint Hetero-Core Fiber Sensors by the Method of Time-Differentiation in Optical Loss

In this paper, we propose the multipoint optical intensity-based measurement of tandem connected intrinsic fiber-optic sensors by means of monitoring time-differentiation in optical loss. The use of hetero-core sensors can make it possible that a simple optical intensity-based measurement combined with a time-differentiation method could be facilitated for the multipoint measurement because the hetero-core technique has a low insertion loss and a sizable loss change in the tandem usage. Addressing multi-sensors has been successfully demonstrated including one displacement sensor and two contact sensors, which are located along a single transmission line in real-time basis. The gait system is also efficiently improved to monitor the knee flexure and the sole contact sensors located in a single transmission line with a mirror at the terminal end of fiber in order to simplify the measurement system for unconstrained monitoring.     

激光目标模拟器校准装置研制

激光目标模拟器被广泛应用于激光制导系统测试,在长期使用过程中,激光信号模拟光源的方位会较大幅度地偏离设计指标,需要对其进行现场校准测试.首先对激光目标模拟器的原理进行了详细分析,进而分别从硬件及软件设计方面对激光目标模拟器校准装置的研制方案进行了阐述.测试结果表明,该装置可准确测量、检定激光信号模拟光源的方位、发射角、...     

高电压脉冲校准装置研究

为解决高电压脉冲的校准问题,对高电压脉冲的校准方法进行研究,并建立了一套脉冲校准装置。校准装置将高电压脉冲信号进行电压转换,变为脉冲小电压,通过数据采集系统,在频带范围10Hz~1kHz、电压范围1~1600V内,对脉冲电压的关键参数进行测量,得到高电压脉冲的电压幅度、脉冲频率、脉冲宽度、上升时间和下降时间。通过实验室标准仪器设备对高电压脉冲校准装置进行测试,其中脉冲幅度的测量误差为 0.02%~0.4%。     

Automation of a surface sampling probe/electrospray mass spectrometry system

An image analysis automation concept and the associated software (HandsFree TLC/MS) were developed to control the surface sampling probe-to-surface distance during operation of a surface sampling electrospray system. This automation system enables both "hands-free" formation of the liquid microjunction used to sample material from the surface and hands-free reoptimization of the microjunction thickness during a surface scan to achieve a fully automated surface sampling system. The image analysis concept and the practical implementation of the monitoring and automated adjustment of the sampling probe-to-surface distance (i.e., liquid microjunction thickness) are presented. The added capabilities for the preexisting surface sampling electrospray system afforded through this software control are illustrated by an example of automated scanning of multiple development lanes on a reversed-phase C8 TLC plate and by imaging inked lettering on a paper surface. The post data acquisition processing and data display aspects of the software package are also discussed.     

基于VB．net的砝码质量空气浮力修正系统设计

砝码质量空气浮力修正系统通过VB．net程序环境搭建,采用PComm串口技术将电子天平质量数据进行读取显示和存储,并通过空气参数采集系统读取、显示并存储大气参数实时数据,将换算得到的空气密度应用到质量校准平台上,来对测试的质量进行实时的空气浮力修正,以提高质量校准在不同大气环境条件下的准确度。本修正系统数据存储采用SQL Server2008设计实现。     

Fiber Bragg grating displacement sensor for movement measurement of tendons and ligaments

Biomechanical studies often involve measurements of the strains developed in tendons or ligaments in posture or locomotion. Fiber-optic sensors present an attractive option for the measurement of strains in tendons and ligaments because of their low cost, ease of implementation, and increased accuracy compared with other implantable transducers. A new displacement sensor based on a fiber Bragg grating and shape memory alloy technology is proposed for the monitoring of tendon and ligament strains in different postures and in locomotion. After sensor calibration in the laboratory, a comparison of the fiber sensors and traditional camera displacement sensors was carried out to evaluate the performance of the fiber sensor during the application of tension to the Achilles tendon. Additional experiments were performed in cadaver knees to assess the suitability of these fiber sensors to measure ligament deformation in a variety of simulated postures. The results demonstrate that the proposed fiber Bragg grating sensor is a highly accurate, easily implantable, and minimally invasive method of measuring tendon and ligament displacement.     

Automated target detection system for hyperspectral imaging sensors

Over the past several years, hyperspectral sensor technology has evolved to the point where real-time processing for operational applications is achievable. Algorithms supporting such sensors must be fully automated and robust. Our approach, for target detection applications, is to select signatures from a target reflectance library database and project them to the at-sensor and collection-specific radiance domain using the weather forecast or radiosonde data. This enables platform-based detection immediately following data acquisition without the need for further atmospheric compensation. One advantage of this method for reflective hyperspectral sensors is the ability to predict the radiance signatures of targets under multiple illumination conditions. A three-phase approach is implemented, where the library generation and data acquisition phases provide the necessary input for the automated detection phase. In addition to employing the target detector itself, this final phase includes a series of automated filters, adaptive thresholding, and confidence assignments to extract the optimal information from the detection scores for each spectral class. Our prototype software is applied to 50 reflective hyperspectral datacubes to measure detection performance over a range of targets, backgrounds, and environmental conditions.     

卫星太阳敏感器模拟器校准技术研究

针对卫星姿轨控半实物仿真系统的技术要求,提出了一种用于太阳敏感器模拟器的校准装置。校准装置以FPGA和AVR单片机为控制核心,微型单板电脑模拟动力学计算机,通过网口进行指令的上传下达。内置信号调理电路、高精度采集模块,数据解算模块等。该校准装置集成度高,替代了原有由数字表、动力学计算机等组成的复杂校准系统,有效地降低了成本,提升效率约40%,实现了太阳敏感器模拟器的快速全过程在线校准。     

热敏电阻在液体火箭发动机试验中的应用

阐述了目前应用于低温推进剂液体火箭发动机试验的热敏电阻温度传感器的特点，介绍了热敏电阻温度传感器在液体火箭发动机试验中的应用方案，包括信号变换器设计、传感器校准数据处理方法、传感器自热效应分析以及测量系统组成，分析了影响测量不确定度的因素，给出了应用热敏电阻温度传感器的测量不确定度小于0．3K。     

一种测量微波功率放大器件输出端反射系数的新方法

本提出了一种测量微功率放大器件输出端反射系数的新方法。通过对可变负载在不同频率和位置下的校准,采用所建立的自动测量系统,运行专门编制的自动控制和数据处理软件,可对微波功率放大器件输出端反射系数进行测量,该方法具有测量简便、迅速、自动化程度高等优点。     

恒温槽校准问题分析及采集软件

分析人工读数对校准结果的波动性、均匀性影响。针对人工读数存在缺陷,提出适用于恒温槽校准自动采集软件方案,并对PDT-2A高精密数字温度计进行基于Visual Basic自动采集软件实现,对软件功能及准确性实验验证。     

泰州大桥结构健康监测系统设计

依托泰州大桥工程概略论述了特大悬索桥梁结构的健康监测系统设计。泰州大桥结构健康监测系统由传感器子系统、数据采集与传输子系统、数据处理与控制子系统3个子系统构成。其中,泰州大桥数据采集与传输系统将传统的有线采集模式和新型的无线采集模式进行了融合,是国内外首次大规模应用。     

Comparison of wear in a total knee replacement under different kinematic conditions

A six station ProSim (Manchester, UK) knee simulator was used to assess the wear of six PFC (DePuy) fixed bearing total knee replacements under two different kinematic conditions defined as low and high kinematic inputs. The high kinematics displacement and rotation inputs were based on the kinematics of the natural knee with ISO standards used for the axial load and flexion. Low kinematics were defined as approximately half the magnitude. The six specimens were run for three million cycles under low kinematics and three million cycles under high kinematics. The mean wear rate found during the low kinematics phase was 7.7 +/- 2 mm3 per million cycles. This then increased significantly to an average wear rate of 41 +/- 14 mm3 during the high kinematics input phase. The wear areas were characterized by a predominant damage mode of burnishing with some abrasive wear occurring during the high kinematics phase. This study supports the findings that introduction of cross-shearing of the polyethylene by introducing both rotational and anterior/posterior displacement increases the wear rate. This has implications for younger patients with higher levels of activity that need knee replacements.