Preliminary Study On Uncertainty Of Measurement Results Of Cable Force Measuring Instrument

The accuracy of the cable force test is one of the research hotspots in the design and operation of the cable bearing system bridge.Based on the theory of metrology,studying the calibration method of the cable force measurement instrument in a specific working environment,making it a measuring instrument for cable force measurement,is an important content of the development of cable force measurement technology.This article examines the “Calibration Device Development” sub-item of the Sichuan Provincial Communications Department Project “Study on Measurement Standards for Force Measurements of Cable Forces”.It is based on the mechanical measurement of metrology and uses the standard method of GUM(Guide to Measurement Uncertainty).Analyze and calculate the components of class A and B uncertainty in the measurement results of the cable force tester,and formulate a technical route for tracing the value of the cable force measurement system.The short cable is used as the measurement object,and the pressure ring is the upper standard device.,Calibrating the cable force tester,researching and determining the calibration scheme of the cable force tester and its key parameters.The main research content is as follows:(1)Analyze and study the type and quantification method of the uncertainty of the force measurement results.The literature on the two methods of the cable force measurement method and the mechanical traceability system was investigated.The measurement conditions,applicable range,and the category and characteristics of the uncertainty of the measurement result were summarized.The uncertainty of the standard device was taken into account.Transmission and motion model parameter probability distribution,analysis of the repeatability,stability and reproducibility of the measurement results,and clear calculation methods of measurement results for Type A and Type B uncertainty and techniques for traceability of cable force measurement system values route.(2)Research on Measurement and Calibration Parameters and Calibration Parameters of Cable Force Measurement Instrument.The technical parameter system of the calibration device with key length,cable diameter,dip angle and cable force as the key indicators was analyzed and determined.Based on the verification of the strength,stiffness and stability of the steel device bearing system of the calibration device,the cable and upper standard device were The tension device and the cable force tester are integrated into the calibration device,and the technical standards of the calibration device are compiled.The structural design and system integration design of the calibration device for the cable force tester are completed.(3)Taking the short cable as the measuring object,the cable force tester was calibrated at the test site.Under the conditions of the test site,the cable force calibration scheme was formulated,and the corresponding measurement model was established.Using the uncertainty theory,the probabilistic characteristics of the relevant parameters were analyzed,and the calculation process of the cable force nominal indication and correction value was clearly defined,and the superior standard device was used.(Pressure ring)Calibrate the cable force tester to obtain the correction value and uncertainty of the cable force tester.Finally,the string theory is used to measure the model and calculate the nominal value of the cable force tester.Its uncertainty.