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Han Y.P.,National Key Laboratory for Electronic Measurement Technology | Li R.H.,North University of China
Applied Mechanics and Materials | Year: 2014

One photoelectrical test method and system were optimal developed for messuring the optical performances of some scintillation crystals. The theoretical Critical Focal Length of the measurement system is firstly deduced and used in order to make the most of both X-ray photons and the effective area of the scintillation crystal panel. Furthermore, coaxial cable ordered is used to replace the carried wire to weaken power noise. Finally, a low-pass filter with 35Hz upper limit cut-off frequency is designed to reduce spike interference of high-frequency noise. Experiments are successfully done to comprehensive test the spectral response, conversion efficiency and spatial resolution of some scintillators, and the results show that the presented system in this paper is helpful to test the scintillator properties. © (2014) Trans Tech Publications, Switzerland. Source

Li X.,National Key Laboratory for Electronic Measurement Technology | Zu J.,National Key Laboratory for Electronic Measurement Technology | Ma T.,National Key Laboratory for Electronic Measurement Technology | Xu P.,North University of China
IEEE Sensors Journal | Year: 2011

The research and development on a novel capacitive pressure sensor with an elastic pressure-sensitive element are presented in this paper. As a coaxial cylinder capacitor converter, it uses a circuit cylinder as its stationary anode and the piezo gauge's shell as its moveable cathode with the electrode distance of 0.5 mm. The device's principle and structure are given, and its mechanical characteristics are theoretically simulated by using the finite element software ANSYS. The read-out circuitry was developed. Various physical properties were experimentally tested. Results show that its capacitance is approximately linear to the subjected pressure. Its sensitivity is 0.0099 pF/Mpa, pressure measuring rang is 0-600 Mpa, By using the sensor's shell as its elastic sensitive element, its volume is reduced and its applications are increased, thus it can be used to measure the chamber pressures of various different caliber guns. In addition, its lower cost is helpful to promoting its applications. © 2006 IEEE. Source

Han Y.P.,National Key Laboratory for Electronic Measurement Technology | Li R.H.,North University of China
Advanced Materials Research | Year: 2014

Spatial sampling criteria and fast recognition theory based on single view imaging system are proposed for automatic testing the assembly structures inside products in industry applications. There must be a maximum rotary step for an object within which the least structural size to be tested is ascertained. Rotating the object by the step and imaging it and so on until a 360°turn is completed, an image sequence is obtained that includes the full structural information for recognition. It is verified that objects could be recognized at a single or some limited orientations by analyzing the correlations among the image sequence. The theory is applied to the online automated X-ray vision system. Experiments show that the average identification takes less than 5s with 4.5% of wrong recognition expense. © (2014) Trans Tech Publications, Switzerland. Source

Gu Y.-L.,Electronic Engineering Institute | Zhang Z.,National Key Laboratory for Electronic Measurement Technology | Wang W.,Electronic Engineering Institute | Fang S.-L.,Electronic Engineering Institute | Shao T.,Electronic Engineering Institute
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2012

According to the situation that electromagnetic environment detecting system only achieved electromagnetic signal detection based on virtual or real platform, the real-time evaluation system of electromagnetic environment complex was designed and realized. Evaluation indices were established based on analysis of factors that influenced electromagnetic environment complex, index weights are acquired by fuzzy comprehensive evaluation method, and the level of complex was computed based on complex evaluation comprehensive values according to the level standard of complex evaluation. Simulation results show that the evaluation algorithm presented can evaluate real-time or historical electromagnetic environment complex, and has a good application value in the field such as military affairs or the civil electromagnetic environment complex evaluation. © Right. Source

Zhang Z.,National Key Laboratory for Electronic Measurement Technology | Zhang Z.,North University of China | Wang W.,North University of China
XXI IMEKO World Congress "Measurement in Research and Industry" | Year: 2015

The paper presents a kind of idea of determining uncertainty of frequency response based on dynamic calibration principles. The paper gives an example of pressure transducer which uncertainty of frequency response is determined by experimental data of multi-time dynamic calibration. It is crucial for widening operational frequency band-width of transducer concerned in the process of inverse filtering or correcting dynamic characteristics in practical applications. Source

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