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2011 Vol. 32, No. 4
Published: 2011-07-22

 
289 Optimal Configuration Method for Large-scale Measurement Systems Based on Form Error Uncertainty
NI Ai-jing,ZHENG Lian-yu
DOI: 10.3969/j.issn.1000-1158.2011.04.01
For large-scale measuring system configuration, the solution to configure measurement systems based on form error uncertainty of measurement task is presented. The point simulation and data fusion from multiple instruments based on Monte Carlo are studied. Based on form error mathematical model, particle swarm optimization method is adopted to solve form error and Monte Carlo method is used to simulate and evaluate form error uncertainty. Finally, the simulation measurement test of a large frame between satellite cabins has been carried out. The test results indicated that the proposed method for optimal measurement systems configuration based on form error uncertainty is effective. This method is able to provide a solution guide for rapid shop-floor deployment of large-scale measurement systems.
2011 Vol. 32 (4): 289-295 [Abstract] ( 436 ) HTML (1 KB)  PDF (1653 KB)  ( 650 )
296 Research on Software Locating of Ultrasonic Testing for Curved Work-pieces
ZHENG Hui-feng,LI Xiong-bing,LV Jiang-Ming
DOI: 10.3969/j.issn.1000-1158.2011.04.02
A multi-graduation match localization algorithm between the testing work-piece and template by software localization method was proposed. First the coordinate was established in surrounding box center of both the testing work-pieces and template one separately. Then the center of mass matching was used to cause actual pose of the testing work-piece to tally basically with the template. Next the final localization was completely realized through the entireness mass matching, which is the last level. All levels of match precision were analyzed through the simulation and the C scanning example was given to confirm this graduation match localization algorithm feasibility. This algorithm has been greatly applied in the ultrasonic testing of airscrew and improved the localization accuracy and ensured the efficiency and reliability of UT.
2011 Vol. 32 (4): 296-300 [Abstract] ( 559 ) HTML (1 KB)  PDF (1286 KB)  ( 523 )
301 Key Arithmetic of Image Accurate Registration for Automatic PCB Drill Photoelectric Inspection
HUANG Yong-lin,YE Yu-tang,Chen Zhen-long;Liu Lin
DOI: 10.3969/j.issn.1000-1158.2011.04.03
In order to realize the fast automatic PCB drill inspection, a fast arithmetic of image registration between standard PCB and testing PCB is proposed. The basic process of the image algorithm and the system structure are introduced. The process of registration is mainly consisted of approximate registration and accurate registration. Edge extraction and Hough transformation are used to obtain 4 corners coordinate of PCB firstly; the coordinates of location hole of the testing PCB can be obtained after approximate registration; the coordinates of circle center of location hole between the testing PCB and standard PCB are used to process accurate registration. Experience shows the method greatly improved the accuracy of image registration. The speed of the arithmetic also meets the needs of the real time process.
2011 Vol. 32 (4): 301-304 [Abstract] ( 479 ) HTML (1 KB)  PDF (858 KB)  ( 767 )
305 Error Analyses for the Algorithms of the Static Fiber-optic Gyro North-finder Schemes
MAO Zhen-hua,ZHOU Wen-qing,LI Jian-shuang,CHEN Ting,HUANG Teng-chao,ZHOU Yi-lan
DOI: 10.3969/j.issn.1000-1158.2011.04.04
Based on the principle of static north finder scheme, error models of several north-finding algorithms were established, and the equations were accordingly deduced to calculate the error with the affection of every parameter in every north-finding algorithm. The result of verifying analysis shows that the four-position north-finding algorithm is less affected by the parameters, such as the latitude of the testing point, and has the higher precision and stability.
2011 Vol. 32 (4): 305-308 [Abstract] ( 423 ) HTML (1 KB)  PDF (657 KB)  ( 408 )
309 Study on the Primary Standard Densitometer for Visual Diffuse Transmission Density
CHEN Rui,LI Zai-qing,LIU Zi-long,WANG Yu,LI Juan
DOI: 10.3969/j.issn.1000-1158.2011.04.05
Primary standard densitometer for visual diffuse transmission density, characterized by hemispherical emitter with optic fiber(HEWOF)is established. Characterization measurements have showed that the geometric and spectral conditions of this densitometer  meet the specifications of ISO 5. Its combined uncertainties are 0.0015(0<D<4.5) and 0.0054(5.0≤D< 6.0).Taking the advantage of that the composite diffuser can be combined respectively with   light source and detection system ,the validity of Helmholtz  reciprocity for transmittance measurement is examined .
2011 Vol. 32 (4): 309-314 [Abstract] ( 708 ) HTML (1 KB)  PDF (1217 KB)  ( 395 )
315 National Proficiency Testing of Calibration for Illuminance Meter Class Ⅰ
JIANG Xiao-mei,MA Yan,YANG Chen-zhu,LIN Yan-dong,CHENG Yao
DOI: 10.3969/j.issn.1000-1158.2011.04.06
National Institute of Metrology had developed M0031 “Calibration for Illuminace Meter Class I” proficiency testing plan which was organized by China National Accreditation Service for Conformity Assessment. In the 103 calibration results given by 26 participating laboratories, 86 results are satisfied, 17 results are unsatisfied. Proficiency testing results are given and the improving suggestions are proposed.
2011 Vol. 32 (4): 315-317 [Abstract] ( 479 ) HTML (1 KB)  PDF (265 KB)  ( 600 )
318 Ultrasonic Gas Flow Metering with Barker Coded Excitation
PU Cheng,ZHANG Tao,QI Lei
DOI: 10.3969/j.issn.1000-1158.2011.04.07
A method using coded excitations combined with correlation to estimate the time-of-flight in transit time ultrasonic gas flowmeters is presented.By theoretical derivation and numrical simulation, it shows that the system with Barker coded excitation has a lower Cramer-Rao Bound of time-of-flight estimation, compared with the traditional threshold method or correlation with tone burst excitation, assuming the same signal to noise ratio (SNR).An ultrasonic gas flow metering system with Barker code binary phase-shifted keying (2PSK) excitation as well as tone burst is designed on FPGA and calibrated by a standard vortex flowmeter with 1% accuracy from 200 to 1 200 m3/h.The results, being in close agreement with the simulations, show that the measuring accuracy and repeatability of the system with Barker coded excitation is better than that of the traditional one.
2011 Vol. 32 (4): 318-323 [Abstract] ( 776 ) HTML (1 KB)  PDF (472 KB)  ( 466 )
324 The Development of 900 nm Irradiation Thermometer
ZHAO Wan-jun,HAO Xiao-peng,YAUAN Zun-dong,YU Fan
DOI: 10.3969/j.issn.1000-1158.2011.04.08
Based on the principle of blackbody radiation,the NIM has been established an irradiation radiation thermometer with center wavelength 900 nm.According to Planck’s law and combining the effective wavelength determination technology in situ, spectral irradiance of a blackbody is measured by this radiation thermometer to calculate the blackbody temperature. The radiation thermometer has the characteristic of simple structure and high stability.The temperature measurement deviation of the thermometry is -0.04 ℃ at the fixed-point of Al with ITS—90 method. And the temperature measurement deviation with RT9032 radiation thermometer is 0.09 ℃ and 0.11 ℃ at the temperature of 800 ℃ and 900 ℃, respectively.
2011 Vol. 32 (4): 324-328 [Abstract] ( 486 ) HTML (1 KB)  PDF (670 KB)  ( 637 )
329 Two Kinds of Uncertainty Evaluation in the Air-enthalpy Method Measuring Cooling Capacity
TENG Jun-heng,HANG Chen-zhe,XU Ding-hua,ZHOU Xue-fen,DU Hong-jun
DOI: 10.3969/j.issn.1000-1158.2011.04.09
Air-enthalpy method is commonly used in measuring cooling capacity of the air conditioner. Some uncertainty evaluation methods for measurement and corresponding mathematical models may exist because of the complex calculating formulas. Base on the formulas for calculating cooling capacity, the two kinds of mathematical models which indicated by intermediate variables and direct testing variables are established. With ten independent measurement data, the results of the two kinds of uncertainty evaluation of are obtained, and the differences between them are analyzed.
2011 Vol. 32 (4): 329-332 [Abstract] ( 533 ) HTML (1 KB)  PDF (275 KB)  ( 912 )
333 Study on Measurement of Static Automotive Load based on Tire Pressure
LUO Guang-zhao,HUANG Li-mei,SHI Wei,YANG Feng
DOI: 10.3969/j.issn.1000-1158.2011.04.10
The mechanism between the automotive load and tire pressure is studied. By measuring the changes of tire pressure of the vehicle, the automotive load can be acquired indirectly. The model of the automotive load and force are analyzed, the effectiveness and practicality of the model are verified by the measurement experiments and error analysis. A novel and portable digital weighing instrument of vehicle load is designed based on the proposed measuring method. This apparatus is mainly composited of a pressure transmitter and a portable display terminal. The tests illustrate that this weighing apparatus feature in higher accuracy, low cost, and small size. It can be applied to the car-load measurement of vehicles in various types of tire.
2011 Vol. 32 (4): 333-337 [Abstract] ( 645 ) HTML (1 KB)  PDF (397 KB)  ( 966 )
338 Study on Fault Diagnosis of Main Drive System of Rolling Mill Based on EMD and AR Spectrum
MENG Zong,GU Hai-yan,LIU Li-hui,YUAN Jing
DOI: 10.3969/j.issn.1000-1158.2011.04.11
According to the non-stationary and non-linear characteristic of rolling mill fault signal, an analysis method based on EMD and AR spectrum is studied. First, the original vibration signals are decomposed by EMD. Subsequently, the IMFs relating to fault information are applied to AR spectrum analysis. The result of this method is the AR spectrum of relating IMFs, from which the fault frequencies can be extracted, and the locations of the faults can be identified. The method is applied to the rolling mill fault signals, then the state of the vibration can be acquired. The validity of the method is demonstrated by simulation and case analysis.
2011 Vol. 32 (4): 338-342 [Abstract] ( 447 ) HTML (1 KB)  PDF (1473 KB)  ( 481 )
343 Study on Internal Electro-optical Measuring Method For Horizontal Tank Volume Measurement
LIU Zi-yong,WANG Jin-tao,GUO Li-gong,ZHANG Long,BAO Xue-song,TONG Lin
DOI: 10.3969/j.issn.1000-1158.2011.04.12
Based on internal electro-optical principle, one automated measuring method used for horizontal tank volume measurement is proposed. A coordinate data analysis algorithm for horizontal tank is discussed, and one volume computation algorithm at each liquid lever is introduced based on Riemann superimposition method. Since the section curve of horizontal tank is irregular, one method for identification between arc and line is proposed according to the curvature computation. One comparison experimental system is designed, and the measurement result from volumetric method is regarded as reference. There is good consistency between volumetric and internal electro-optical method. With the increase of liquid level, the relative error became smaller, and the full range relative error is 0.2%, which verified the measuring method discussed.
2011 Vol. 32 (4): 343-345 [Abstract] ( 505 ) HTML (1 KB)  PDF (484 KB)  ( 517 )
346 Calibration Data Processing and Volume Table Generation for a Tank
HU Li-kun,XIE Shu-ping,HUANG Wen-qin
DOI: 10.3969/j.issn.1000-1158.2011.04.13
The method of calibration data analysis and volume table generation for a horizontal storage tank are presented, which is based on cubic smoothing spline and symmetric mapping algorithm. It is used to solve the problem such as incline, expansion and creep caused by topography, temperature, pressure. The problem will cause the uncertainty of capacity. At the same time, a system about the calibration data analysis of horizontal storage tank and the volume table is established. The feasibility of this method is verified by case analysis and comparison. The field-application shows that it is valid to process calibration date of the horizontal storage tank.
2011 Vol. 32 (4): 346-350 [Abstract] ( 417 ) HTML (1 KB)  PDF (393 KB)  ( 664 )
351 Research on Subsection Linear Torque-Curren Model of a Magnetorheological Fluids Actuator
WEN Ci,SONG Ai-guo,WANG Ai-min
DOI: 10.3969/j.issn.1000-1158.2011.04.14
A magnetorheological fluid (MRF) actuator controlled output torque through input current. Exact knowledge of the relationship between the torque and current was the key. A novel subsection linear torque-current model considering hysteresis was presented. The torque formula of cylindrical MRF actuator based on the Bingham plastic model was derived. The magnetic properties of ferromagnetic materials and MRF were studied. A hysteresis behavior was observed in the torque-current experimental curve. The validity of the subsection linear model is verified by comparison the quadratic-multinomial model, subsection linear model and experimental data.
2011 Vol. 32 (4): 351-355 [Abstract] ( 443 ) HTML (1 KB)  PDF (1190 KB)  ( 581 )
356 Measurement of Thermal Conductivity of Magnetic Fluids under External Uniform Magnetic Field Using Transient Hot-wire Method
GU Bang-ming,WANG Zheng-liang,ZHANG Li-qiao,CHEN Shan-fei
DOI: 10.3969/j.issn.1000-1158.2011.04.15
Polymeric α-olefin based magnetic fluids sealed in two glass tubes were placed in external magnetic field. To eliminate the end effect and the natural convection induced by magnetic field force and gravity force, the transient hot-wire (THW) instrument was developed for accurate measurements of the thermal conductivity of magnetic fluids. The hot-wire apparatus was calibrated utilizing distilled water and anhydrous alcohol as reference fluids, which showed that the experimental system has a high accuracy. Effects of the direction of external magnetic field to the magnetic fluids with different volume fraction of suspended magnetic particles were measured. Results indicated that: when the direction of external magnetic field was parallel to the heat flow (the temperature gradient), the thermal conductivity of the magnetic fluid increased greatly. The conductivity increased almost linearly with the strength of the magnetic field, the higher the particle concentration, the more increment was. On the other hand, when the magnetic field was perpendicular to the heat flow, little change in the thermal conductivity was found.
2011 Vol. 32 (4): 356-360 [Abstract] ( 575 ) HTML (1 KB)  PDF (826 KB)  ( 452 )
361 The Uncertainty of Trigger Delay of Waveform Recorders
LIANG Zhi-guo,MENG Xiao-feng
DOI: 10.3969/j.issn.1000-1158.2011.04.16
The evaluation method for trigger delay of waveform recorders are presented.By using a sinusoidal stimulating,one can take the sampling waves of both trigger delay and non-trigger delay,and then obtain the trigger delay from the phase difference.Some error sources are discussed,including the errors of signal generators,the harmonic distortion,the noise and the spurious distortion,the jitter of the sampling series,the triggering jitters,and the curve-fitting errors of the software,etc.Meanwhile,the uncertainty analysis are introduced in detailed,the measurement uncertainty of trigger delay are taken out.By using experiment,the feasibility and validity are proved.
2011 Vol. 32 (4): 361-367 [Abstract] ( 419 ) HTML (1 KB)  PDF (1353 KB)  ( 502 )
368 Palm Print Image De-noising Based on 2-D EMD and Wavelet Thresholding
DAI Gui-ping
DOI: 10.3969/j.issn.1000-1158.2011.04.17
In order to suppress the palm print image noise effectively and extract the palm print features accurately, a novel de-noising method based on 2-D EMD and wavelet thresholding was proposed. Firstly, the preprocessed palm print image containing noise was decomposed into some IMFs by 2-D EMD, and then the first several IMFs were processed by using wavelet thresholding de-noising method; finally, the image was reconstructed through adding the processed IMFs and the residual component. Experimental results show that the proposed method has a good effect on suppressing noise. Compared to the wavelet thresholding and 2-D EMD de-noising, the method not only has advantages of more sufficiently retaining edge and detail information while de-noising, but also achieves superior PSNR (peak signal-noise-ratio) of the reconstructed image.
2011 Vol. 32 (4): 368-372 [Abstract] ( 556 ) HTML (1 KB)  PDF (1445 KB)  ( 595 )
373 Preparation of 3-nitro-1,2,4-triazol-5-one Reference Material
ZHOU Cheng,CHEN Zhi-qun,HUANG Xin-ping,ZHOU Yan-shui,HUO Huan
DOI: 10.3969/j.issn.1000-1158.2011.04.18
The method of preparation for 3-nitro-1,2,4-triazol-5-one (NTO) reference material is described. The NTO reference material is prepared with the industrial product as primary substance by heat-filtration, recrystallization, vacuum drying etc. The purity of the NTO reference material is determined by HPLC. Its homogeneity and stability is tested by variance analysis method. The results show that the purity of the NTO reference material is 99.91%, the homogeneity are good, the stability term is over one year and it can meet the required qualification of the reference material.
2011 Vol. 32 (4): 373-376 [Abstract] ( 576 ) HTML (1 KB)  PDF (334 KB)  ( 899 )
377 Comparison of Air Kerma in 60Co Gamma Rays
WANG Kun,ZHANG Hui,YANG Xiao-yuan,HU Jia-cheng,YANG Yuan-di
DOI: 10.3969/j.issn.1000-1158.2011.04.19
National Institute of Metrology organized the comparison for air kerma in 60Co gamma rays in China.There are 15 laboratories join the comparison.The results show that the comparison difference of air kerma rate in reference point is within 0.6%, and the comparison difference of calibration factor for air kerma of transfer chambers is within 0.8%.
2011 Vol. 32 (4): 377-380 [Abstract] ( 447 ) HTML (1 KB)  PDF (288 KB)  ( 547 )
381 Study on Measuring Method of Optical Characteristics of Photoresist by Spectroscopic Ellipsometry
LIU Wen-de,CHEN Chi,CHEN Xi,YU Jing,ZHENG Chun-di,WANG Yu
DOI: 10.3969/j.issn.1000-1158.2011.04.20
By means of phase-modulated ellipsometer,the method for measuring optical constants of photoresist is described.The test scheme and instrument parameters for testing process of photoresist are optimized.For commonly used positive S9912 photoresist,the optical constants for 275~650 nm before/after the exposure are measured,and the dynamic ellipsometry is used to obtain the values before the exposure at wavelengths of interest.The experimental results indicate:the method provided is applicable for the research of photoresist in UV-VIS-NIR spectral range and may find important application in the optical lithography simulation,the development and characterization of new-type photoresist materials.
2011 Vol. 32 (4): 381-384 [Abstract] ( 549 ) HTML (1 KB)  PDF (349 KB)  ( 1205 )
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