Abstract:The optical elements with aspheric surface are widely applied now in many fields,where the measurement of aspheric surface plays a critical role.The measuring methods for small aspheric optical elements are introduced in this paper.Then according to the measuring principle the methods are classified and compared.The advantages,disadvantages and application scope of the methods are also discussed.Finally,the critical problems and facing challenges in realization of these methods are analyzed.

Abstract:Today the mass standard is the last remaining SI unit based on an unique manmade object.Through the international cooperation the metrologists are striving to redefine the mass standard depending on unchanging properties of nature-based on the concept of Avogadro constant and Planck's constant.

Abstract:Based on orthogonal transform,a new method of tracking power grids frequency has been provided.Simulations with respect to two models,prove that the method can track the frequency accurately and instantly,and have the preferable effectiveness on the abruptly fluctuating-frequency power signals,at the same time,this method overcomes the constraint of synchronous sampling and has the better astringency with different initial frequency.

Abstract:During measurement of gas flow temperature,there are radiation error,conduction error and velocity error.This paper studies optimal design of lengthways-single-sheath-thermal-couples from decreasing the temperature measurement errors,then it is on chance of providing reference for design of lengthways-single-sheath-thermal-couples.

Abstract:Follow the traditional evaluation method for the absolute testing of three optic flats, the result of the deviation can be evaluated by the deviation on two perpendicular diameters, its evaluation method is different from the true surface graph exactly. This text introduces a rotation method for the absolute testing of three optic flats, which is based on the photoelectric detecting technique, laser interference technique and image manipulation technique, it can solve the deviation on N diameters of each optic flat and enhance the accuracy.

Abstract:For the problem of telemetry communication can not meet the demand of the real-time observing on the ground, this paper proposes a method which applied the envelope analysis to data compression and transmission of flight tests, it provides an effective way for the real-time transmission of telemetry data. First, by picking up the extreme points, interpolating and fitting, the envelope of the telemetry data is acquired. And then the spectrum of the envelope is calculated and according to the sampling theorem, the re-sampling frequency is decided, which could achieve the reduction of data transmission on the premise of maintaining the basic characteristic and change rule of the data. In the end, through processing and analyzing a group of actual telemetry vibrational data, the efficiency of the method was testified.

Abstract:In this paper, a self-calibration technique of the camera based on three vanishing points is introduced. This calibrating method is realized by the constrained condition among the vanishing points obtained by using three groups of in pairs orthogonal parallel lines in the nature scene. The optimization correction of the obtained vanishing points can be obtained. The experimental research has been done and the result has been compared with the traditional method. The result shows that the algorithm proposed in this paper has better application prospeet.

Abstract:Some different points of view to the article 'the value analysis for standard military measure' are presented in the aspects of the nature of analysis,key procedures and application of value analysis etc.

Abstract:Existing calibration methods of laser speedometer are summed up and one new calibration method and instrument with simulant target is put forward in this paper.Comparison analysis and experiments show that the calibration instrument can meet the need of laser speedometer calibration because of its wide calibration range,high repeatability and universal performance.

Abstract:The rivet joint resistance measuring instrument is the special instrument used for measuring the airplane rivet joint parts contact quality,it is important to promise the normal work of the electronic equipments and the communication system of the airplane.During maintenance of the airplane,should test the body resistance to make sure whether it meets the requirement.This text introduces the aim of developing the measuring instrument,its working principle and electric circuit construction.

Abstract:In order to meet the requirement of the new regional aircraft electric power system(EPS) independent test,a simulator is designed to be used to simulate the relative interface function among the avionics system,engine system and the EPS.It mainly provides the simulated signals of some other systems for the EPS and indicates EPS operating status.It provides support for testing and verifying the performances of the power supply system.The result shows that under 12 different kinds of EPS statuses the simulator can provide correct control logic for ELEC PWR CPA and EPS,indicate reasonable information for EPS synopsis and EICAS and transmit information properly between generator control units and simulator by ARINC429 bus.All of the functions of the simulator are in accordance with the specifications of the aircraft and can meet the aircraft EPS test program demand.

Abstract:This paper introduces a method of calibrating and processing angular speed fluctuation in NI sampling system-PXI-6281 ,it accomplishes the acquisition of angular speed fluctuation by distortion of signal, analyzing fundamental wave, high-order harmonic of angular speed feedback signal, and calculating the amplitude ratio of base-wave and high-order harmonic.

Abstract:In many satellite TT&C systems,the standard signal tower has been used in signal calibration.As a matter of fact,there are some disadvantages with this method.To overcome these limitations,this paper presents a method of static tower-less calibration method based on satellite TT&C system,and the concrete approach of implementation of tower-less calibrating phase and zero position is put forward.

Abstract:The paper introduces the principles and components of the multi-joint CMM,and does the error analysis.It also analyzes the influence of the eccentricity error of the circular optic grating installation on the results,and introduces the measuring method of graduation error.This error has been corrected by the nonlinearity fitting.

Abstract:In this paper,the influence of the impact block mass and the impact height in Leeb hardness measurement are analyzed with the method of orthogonal experiments.Meanwhile,an acceptable change range of the two factors is given.

Abstract:The composition,principle,methods of measurement and design of the software for the semi-automatic verification system of DC resistance box are introduced, and the feasibility of the system is testified in this article.

Abstract:In this paper,it is described that the uncertainty of evaluation results of DC gain and offset of linear measurement system by using the terminal-based straight line method,including the courses of analysis and evaluation of uncertainty.Some error sources of evaluation are discussed,including the errors of signal source,the measurement errors of the calibrated system,the influence of quantization error of calibrated system,the environment influence,and so on.Both the DC gain uncertainty and the offset uncertainty of terminal-based line measurement systems are given out.For an example of experiment,the analysis and uncertainty evaluation results of both DC gain and offset by using the method in this paper is presented.The verification of the uncertainty has proved the correctness and feasibility of the above method.The courses and conclusion proposed can be applied to the uncertainty evaluation of measurement standards of both DC gain and offset.

Abstract:In this paper, the hardware and software designs have been proposed based on single chip microcomputer of PIC16F87X to control SA8282, drive IGBT, and in order to generate the AC pure sinusoid on the basic of static-inverter. With the digital PID modulation the precision and stabilization of the output voltage of the power supply have been enhanced. Experimental results show the output voltage waveform is good, and the performance meets the requirement.

Abstract:In order to make the bell-jar gas flow standard equipment used for many years of Chengdu Air Company can be used continuously,the low cost upgrading transform has been done.The auto-measurent of all of the four sets of the equipments in the company has been realized.

Abstract:This paper presents a nonaqueous liquid rotameter calibrating equipment of type LB311.Based on the standard method and adopting one big and one small centrifugal pumps for supplying the stabilized flow source,the turbine flowmeter is adopted as the standard to calibrate the rotameter.The range of measurement is wide.Because of adopting three ralves adjusting system,the adjustable accuracy is high.

Abstract:针对黑体式光电高温计中输出光电流范围较宽,并与温度呈近似指数关系、不易处理的问题,提出了基于精密对数放大器LOG100设计的调理电路,将宽范围的光电流转化为0～5V电压,便于进行A/D转换,提高了测温灵敏度,拓宽了测温范围,比传统的分立元件电路简单、可靠.实验表明:该方法测量灵敏度高,可以满足高温计最大测温偏差0.5%的要求.