The Dynamic Calibraition Methods Of The Target Flowmeter

Target flowmeter is widely used in industrial flow measurement,especially suitable for the flow measurement of fluid with high viscosity, lowReynolds number. But in the practical application, Target flowmeter oftencan’t reflect true conditions of fluid flow in the pulsating fluid flow, mixedfluid flow and other unstable fluid flow conditions. In addition，when the flowvelocity is faster, target flowmeter will often come across the resonance oftarget bar that make target flowmeter doesn’t work normally. In essence, theseproblems have roots in bad dynamic characteristics of target flowmeter. Sowhen target flowmeter meets unstable fluid flow, the output of the targetflowmeter usually cannot reflect the conditions of the input of it. Therefore,the dynamic calibration of the target flowmeter is very necessary.At present, all flowmeter manufacturers carry out the static calibrationbefore their products are sold into markets and gives the customer a relatedstatic calibration certificate.But most of them have not relevant performanceindex of dynamic characteristics.The thesis studied the methods of dynamiccalibration of target flowmeter to find a reasonable and low-cost scheme,which could obtain some related performance index that can reflect thedynamic characteristics of target flowmeter, based on analyzing and studyingthe principle and the production process of target flowmeter.The main research is as follows:(1) Introduce the development trend of flowmeter and summarize theexisting calibration methods and the shortcomings of these methods.(2) Analyze and study the principle, structural features and productionprocess of target flowmeter. On the basis of these, put forward severalfeasible dynamic calibration schemes and the method of data acquisition.(3) Introduce detailedly how to adopt data processing methods of FFT,Power spectral density and System identification to get the dynamic characteristic of target flowmeter.(4) Carry out the experiment of the dynamic calibration schemes,analyzing and verifying the experimental results.(5) Research results of the thesis have a good inspiration and guidance toanalyze and study the dynamic characteristics of target flowmeter, laying agood foundation to the research of improving the dynamic characteristics.