Papers by Keyword: Measurement System

Abstract: A dynamic calibration method based on elliptical standard was put forward to further improve the calibration repeatability of measurement system of form measuring instruments. In this method, the radius difference of the major axis to the minor axis of elliptic contour acts as the standard value to calibrate the measuring system, and a low pass filter is used to filter the roughness, electrical noise and high frequency vibration signal which mixed into measurement data, the elliptic contour feature can be obtained accurately based on the low order harmonic properties. Compared with the traditional calibration method of flick standard, the proposed method ensure the calibration state is well consistent with the normal measuring state of the measuring system. Experimental results indicate that the calibration repeatability with 10nm can be achieved by measuring an elliptical standard. This method has been used in the calibration of measurement system of self-made ultra-precision cylindricity measuring instrument.

Abstract: The article is devoted to compare the size of the creep for a time period of cement pastes with admixture of different amounts of fly ash. Attention is given to the size of the deformations that occur in materials saturated with water and also in the dried matrices. The presented results comparing creep size for cement pastes containing fly ash 30 and 50 %. Influence of the amount of ash and the amount of water to the creep size is evaluated in the conclusion.

Abstract: Based on multi-thread technology, completed a set of real-time dynamic measurement system apply on binocular vision principle. Real time measurement require of system efficiency higher, multithreaded programming can greatly improve the efficiency of program. Binocular dynamic real-time detection is based on closed-loop control system, puts forward a multithreaded programming technology which is based on the binocular vision high-speed dynamic measurement method. The data acquisition, processing, display are using multithreading technology.

Abstract: The system developed at the Institute for Sustainable Technologies – National Research Institute is intended for heat recuperation efficiency tests for recuperators used in ventilation systems in modern, passive buildings. It allows a complex and precise assessment of the efficiency of recuperators, directly influencing the cost of energy used to provide thermal comfort inside a building.

Abstract: According to the industrial site of precision measurement and control systems, the demand for real-time monitoring and multi-task, the paper studied and designed an industrial site monitoring and control system based on Labview; overall structure of software and hardware, the system was designed system, the system platform-level and user-level using a two-stage multi-task scheduling strategy to achieve the industrial field parallel scheduling and control system to improve the operating efficiency of monitoring and control systems; practice shows that the system has high accuracy, strong and stable real-time, etc., to meet the monitoring needs of the industrial field, with a good prospect.

Abstract: The paper deals with new indirect methods of leakage flow rate measurement in compressed air pipelines. In this method the measurement equipment has branch connection to the pipeline. The measurement method consists in determining the relation between air leakage flow rate in pipeline and the controlled air flow rate through adjustable throttle valve. Compressed air leakage flow rate in pipeline is calculated on the basis of pressure ratio measurements in two time intervals - during leakage without the controlled flow and with the controlled flow in branch line. The controlled air flow through the throttle valve is directly measured by flow meter.

Abstract: For the more complicated principles and the lower accuracy for the existing methods of the measurement of the analog circuit parameters, the paper constructs a measurement system for the analog circuits parameters based on the multiplier. The signal source generates two orthogonal sinusoidal analog signals with same frequency, and then one of the signals goes through the analog circuits. Then the multiplication and filtering are completed with the two DC signals. At last the phase and amplitude of the analog circuit are obtained through the DAQ and LabVIEW software. The amplitude and phase errors are less than 3%. The results show that the system has simple circuit, fast speed and high accuracy. So it is a feasible plan for the measurement system of the analog circuit parameters at present.

Abstract: The integral system model is designed in this paper, based on the principle of equal area. This paper introduces the structure of the model, analyses the main parameters in the system and describe the working principle of the system, combining with the question of abnormal integral, this paper gives concrete application method.

Abstract: This paper presents the design and realization of pressure measurement system used in FPGA processors with pressure sensor temperature drift compensation by software. This paper discusses in detail the realization of measurement system circuit, the internal structure design of FPGA software, the compensation algorithm analysis and design, and the simulation of FPGA. Finally through the test results validate the design of pressure measurement system with temperature compensation is feasible and effective.

Abstract: Calculations of capability and performance indices are based on measurement results. The uncertainty of the measurement process used to generate capability and performance indices must be estimated before the indices can be meaningful. The actual measurement uncertainty needs to be adequately small.To demonstrate the suitability of measurement processes, were in the industrial production process based on the MSA version 4 (AIAG Measurement System Analysis [) is used.Another procedure is based on the ISO 98-3 ISO; Guide to the Expression of Uncertainty in Measurement (GUM) [. But this is not practical in production. Therefore, the ISO 22514-7 [ was published. This document is in the FDIS (Final Draft ISO) status and will be official until mid-2012 as an ISO Standard. The VDA 5; Measurement Process Capability [ is also based on this new standard