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2012 Vol. 33, No. 6
Published: 2012-11-22
 
481 Study on Sensitivity-adjustable Fiber Bragg Grating Obliquity Sensor
SUN Wei,LIANG Da-kai,ZENG Jie,FENG Li-hang,YE Ting
DOI: 10.3969/j.issn.1000-1158.2012.06.01
A new sensitivity-adjustable fiber Bragg grating (FBG) obliquity sensor based on the deformation theory of the constant-section beam is described. The obliquity sensor can achieve the measurement of object’s angle by the way that the FBG experiences the deformation of the constant-section beam due to the change of object’s angle,and corresponding FBG obliquity measuring system was set up. Experimental results show that the measuring range is ±35°,the highest sensitivity is 56.93pm/(°),the measurement accuracy is 0.02°,and the sensor sensitivity can be adjusted by altering the size of the constant-section beam.
2012 Vol. 33 (6): 481-485 [Abstract] ( 511 ) HTML (1 KB)  PDF (572 KB)  ( 710 )
486 Analysis and Evaluation of AFM Uncertainty in Linewidth Measurement
HAN Guo-qiang,CHEN Yu-qin
DOI: 10.3969/j.issn.1000-1158.2012.06.02
The sources of linewidth measurement uncertainty of AFM type P47 are analyzed in details.A new model based on geometry shape of linewidth measurement is proposed.An uncertainty evaluation method is offered according to systematic analysis results in linewidth measurement.The measurement uncertainty component caused by traditional Si3N4AFM tip is about 5% of the total linewidth.Finally,the main measurement uncertainty source- AFM tip is determined.
2012 Vol. 33 (6): 486-489 [Abstract] ( 558 ) HTML (1 KB)  PDF (871 KB)  ( 691 )
490 High Precision Roundness Measurement for Large Cylindrical Shaft Based on Multiple Capacitance Sensors
KANG Yan-hui,ZHANG Heng,LI Ying-zhong
DOI: 10.3969/j.issn.1000-1158.2012.06.03
In order to realize the high precision roundness on-line measurement for large cylindrical shaft, a non-contact roundness measurement system based on multiple capacitance sensors is developed, which can measure the range of Ф800 mm. The roundness measurement methods for the shaft of large high-precision rotary tables are analyzed, especially the error separation technique by three-point method. The principle and structure of capacitance sensor are discussed, and the system composition and data evaluation methods are presented. Compared with a high precision roundness measurement equipment, the experimental result shows that the indication error is better than 0.1 μm and repeatability is less than 0.05 μm, which can satisfy the field measurement.
2012 Vol. 33 (6): 490-493 [Abstract] ( 538 ) HTML (1 KB)  PDF (4279 KB)  ( 496 )
494 Responsivity Standard of Optical Detector Based on the Cryogenic Radiometer
LIN Yan-dong,Lü Liang
DOI: 10.3969/j.issn.1000-1158.2012.06.04
Standard of responsivity of optical detector at laser wavelengths is established based on the cryogenic radiometer.Performance of the standard facility is characterized,and the uncertainty evaluation test for the effective radiant heating power is applied.The responsivity of the standard detectors,a group of trap detectors,is measured at ten wavelengths of He-Ne,Ar+Kr+ and Ti sapphire lasers.The measurement uncertainties are 0.8×10-4 at He-Ne and Ar+Kr+ laser wavelengths and reaches 1.1×10-4 at Ti sapphire laser wavelengths.The influence of spatial non-uniformity,non-linearity, polarization dependence,angular dependence on responsivity of the standard detector is investigated.
2012 Vol. 33 (6): 494-498 [Abstract] ( 657 ) HTML (1 KB)  PDF (347 KB)  ( 968 )
499 Self-repairing Implementation of the Fiber Bragg Grating Sensor Network
ZHANG Xiao-li,LIANG Da-kai,ZENG Jie,LU Ji-yun
DOI: 10.3969/j.issn.1000-1158.2012.06.05
For the fiber Bragg grating sensor network, how to increase the external load position identification precision of a certain aircraft wing box adopting to the support vector machine is an important problem. The influence degree of the position identification precision when partial optic fiber sensor failure in the network is analyzed and the fault-tolerant position identification algorithm based on the model reconstruct in terms of the failure condition is proposed.Meanwhile the load position identification precision before and after adopting to the model reconstruct position identification algorithm is compared in detail.The result indicates that the model reconstruct fault-tolerant identification algorithm can realize the self-repairing of the fiber Bragg grating sensor network effectively when partial sensor failure, and the reliability of the sensor network is improved.
2012 Vol. 33 (6): 499-504 [Abstract] ( 640 ) HTML (1 KB)  PDF (1235 KB)  ( 477 )
505 Uncertainty Evaluation of Retroreflection Measurement Standard Equipment
ZHU Chuan-zheng,LI Wei,YANG Yong,BAI Yuan-yuan
DOI: 10.3969/j.issn.1000-1158.2012.06.06
A study on the measuring principle and process of retroreflection standard equipment was carried out, and two mathematical models, coefficient of luminous intenstiy and coefficient of retroreflection, were established. Then the two models influencing factors were analysed and main sources and distribution characteristics of the measurement uncertainty were founded. According to the theory of uncertainty, uncertainty components were evaluated separately. At last, combined measurement uncertainty was calculated and uncertainty report was proposed. The results show that the measurement uncertainty is 4.0% or 4.3% in different values range.
2012 Vol. 33 (6): 505-508 [Abstract] ( 596 ) HTML (1 KB)  PDF (400 KB)  ( 596 )
509 The Experiment Study for SSE on Calibration of Infrared Thermometer under Lower Temperature Condition
ZHAO Quan-qin,LI Wen-jun,SUN Jian,YU Shi-fan,ZHANG Long-fei,CUI Chao
DOI: 10.3969/j.issn.1000-1158.2012.06.07
The phenomenon of size-of-source effect (SSE) is discussed and the coefficient of SSE is used for estimating the SSE property of the infrared thermometer. The experiment apparatus used for measuring SSE under lower temperatures condition is described, and several types of infrared thermometers are applied to the measurements of SSE. The experiment results indicate that the influence of SSE may be not considered at the diameters of the diaphragm hole being more than 40mm. This conclusion is suitable to the most industrial infrared thermometers.
2012 Vol. 33 (6): 509-512 [Abstract] ( 537 ) HTML (1 KB)  PDF (1070 KB)  ( 511 )
513 Simulation and Design of the Small Pipe Ultrasonic Flowmeter
ZHAO Wei-guo,ZHAO Xue-song,HUANG Chao-chuan
DOI: 10.3969/j.issn.1000-1158.2012.06.08
In order to solve the problem of small pipe measurement of transit-time ultrasonic flowmeter, the inner acoustic reflection device and tapered pipe were designed. The flow correct coefficient K and its RMS error were adopted as the evaluation standard. The shape, size and distance of the reflectors and the size of tapered pipe were studied with FLUENT software. Then the optimal pipe model was designed. The coefficients of the model at different flow points were also calculated. The simulation results showed that the flow pipe model is stable and can improve the accuracy of the small pipe measurement.
2012 Vol. 33 (6): 513-518 [Abstract] ( 483 ) HTML (1 KB)  PDF (3293 KB)  ( 717 )
519 Numerical Simulation of Electromagnetic Flowmeter Based on Magnetohydradynamics and Computational Fluid Dynamics
LU Bo,XU Liang-wang
DOI: 10.3969/j.issn.1000-1158.2012.06.09
A method for predicting the characteristics of an electromagnetic flowmeter was applied based on magnetohydradymics(MHD)and computational fluid dynamics(CFD).MHD simulations can directly study the detailed interaction between the fluid flow and the externally applied magnetic field,including the relationship between the output signal and the flow rate using a two-dimensional model.The results show that the model agrees with the theoretical values,indicating that MHD and CFD can be applied for studying the characteristics of an electromagnetic flowmeter under flow and external magnetic field conditions.
2012 Vol. 33 (6): 519-522 [Abstract] ( 554 ) HTML (1 KB)  PDF (1091 KB)  ( 1006 )
523 Design of Flexible Pressure Tactile Sensor for Robot Joint
HUANG Ying,LU Wei,ZHAO Xiao-wen,ZHAO Xing
DOI: 10.3969/j.issn.1000-1158.2012.06.10
On the based of analysis of the tensile, bendability and pressure sensitive characteristics of carbon fiber/silicone rubber, a new flexible pressure tactile sensor for some robot movement parts such as joint is designed. Using decoupled arithmetic to solve the interference problem caused by the sensor stretched or bent, a mathematical model to calculating the contact pressure is constructed. The experimental results demonstrate that the flexible pressure tactile sensor is stretchable and bendable, and eliminates the stretching and bending interference on contact pressure detection, so it can be used in robot joint.
2012 Vol. 33 (6): 523-527 [Abstract] ( 539 ) HTML (1 KB)  PDF (552 KB)  ( 1010 )
528 A New Method for Low Differential Gauge Pressure MeasurementBased on Piston Guage and Digital Pressure Gauge
LI Yan-hua,SUN Jun-feng
DOI: 10.3969/j.issn.1000-1158.2012.06.11
A method for measuring the low differential or gauge pressure with the combination of a piston gauge (PG), a digital pressure gauge (DPG) and a special connected way of a bypass is described. The problem of the lower pressure limit due to the load mass of the piston itself is solved. By the advantage of perfect short-term stability of the DPG and the lower uncertainty of the PG, the differential pressure or gauge pressure up to 10kPa could be measured, the expanded uncertainty of the measurement is 2.2Pa with k=2.
2012 Vol. 33 (6): 528-531 [Abstract] ( 444 ) HTML (1 KB)  PDF (290 KB)  ( 557 )
532 Vibration Signal Analysis Based on Fractional Fourier Transform
GAO Yu,HUANG Yi-jian
DOI: 10.3969/j.issn.1000-1158.2012.06.12
Simulation results verify that the fractional fourier transform can suppress gaussian noise and detect the chirp signal. Mechanical vibration experiments further prove that the fractional fourier transform not only analyses stationary signals, but also is more objective to show the spectral characteristics of the signal than that by the traditional fourier transform for analysis of nonstationary signals,and extract non-stationary components.
2012 Vol. 33 (6): 532-536 [Abstract] ( 499 ) HTML (1 KB)  PDF (1626 KB)  ( 805 )
536 A New Angular Acceleration Sensor Based on Electromagnetic Induction and Its Error Analysis
ZHAO Hao,FENG Hao
DOI: 10.3969/j.issn.1000-1158.2012.06.13
For the shaft angular acceleration is the key to its state inspection and fault analysis, a new angular acceleration sensor based on the principle of electromagnetic induction is designed. The tests were carried out for three-phase asynchronous motor、single phase ac induction motor and no slot of rotor three-phase asynchronous motor. The experiments show that when the rotary system exist angular acceleration component, this component is output in the form of induced potential through electromagnetic coupling, the sensor can reflect the changes of mechanical angular acceleration. The sensor actual working condition are analysed, the output characteristics and the transfer function of sensor are infered, it affords effective technical support for the popularization and application of the sensors.
2012 Vol. 33 (6): 536-540 [Abstract] ( 489 ) HTML (1 KB)  PDF (1147 KB)  ( 930 )
541 Establishment of National Voltage Ratio Standard for 1000kV at Power Frequency Based on the Series Voltage Summation
ZHOU Feng,YUE Chang-xi,LEI Min,WANG Le-ren,JIANG Chun-yang
DOI: 10.3969/j.issn.1000-1158.2012.06.14
Based on a specially designed 1000kV series standard voltage transformer with high accuracy of 0.01 level,an experiment of 1000kV power frequency voltage summation is finished successfully by National Center for High Voltage Measurement .The experimental results show that the uncertainties of measurement of voltage ratio error and phase difference are not more than 2×10-5 and 0.06′ respectively. Compared the results by the traditional voltage coefficient measuring method with an 800kV compressed gas capacitors, the maximum deviation of voltage ratio error and phase difference is 2.7×10-5 and 0.11′ respectively.And neither of the maximum deviations exceeds 90% confidence interval of values of the two methods.
2012 Vol. 33 (6): 541-545 [Abstract] ( 499 ) HTML (1 KB)  PDF (1072 KB)  ( 977 )
546 BP Neural Networks Based on Adaptive Genetic Algorithms and Its Application to Prediction of Battery Capacity
FENG Nan,WANG Zhen-chen,PANG Ying
DOI: 10.3969/j.issn.1000-1158.2012.06.15
A model is created by adopting BP neural network to predict the state of charge of battery, and adaptive genetic algorithm(AGA) is utilized to optimize its weights and bias, to analyze many factors that affecting the battery residual capacity.Finally, with the emulation program written by MATLAB, multiple sets of data are tested and compared with pure BP network and GA-BP network.The results show that the AGA-BP network has a short training time and high accuracy. It is effective for prediction of the any state battery capacity.
2012 Vol. 33 (6): 546-549 [Abstract] ( 536 ) HTML (1 KB)  PDF (1094 KB)  ( 973 )
550 Study on Peak Power Meter Calibration
ZHAO Hai-ning,HOU Li-xin,ZHOU Xin
DOI: 10.3969/j.issn.1000-1158.2012.06.16
In modern digital mobile communications system, the signals are transmitted in burst mode that requires power meter be able to measure the power of discontinuous signal, so frist,the peak power and burst power meters are introduced. Those special parameters about the power of burst signal and the measurement theory of peak power meter are also introduced. The theory and method of calibrating peak power meter are described combined with the characters of those parameters. Finally, calibration results and measurement uncertainty analysis are reported,the expanded uncertainty is 0.17 dB, the system can meet the calibration requirements of the peak power meter.
2012 Vol. 33 (6): 550-554 [Abstract] ( 599 ) HTML (1 KB)  PDF (1233 KB)  ( 415 )
555 The Uncertainty Evaluation of Rise Time of Digital Storage Oscilloscopes
LIANG Zhi-guo
DOI: 10.3969/j.issn.1000-1158.2012.06.17
The uncertainty of evaluation results of transient duration (rise time) of digital storage oscilloscope (DSO) by the step input method is described, including the courses of analysis and evaluation of uncertainty of it.Some error sources of rise time evaluation are discussed, including the signal rise time & its errors, the time base errors of DSO, the amplitude measuring errors of DSO, the effect of the slope of the curve, the repeatability errors, and the others.The uncertainty model of rise time of DSO is given, and several main methods about decreasing the rise time evaluation errors and evaluation uncertainty are proposed.Combining with an example of experiment, the analysis and uncertainty evaluation results of rise time with the method is presented.
2012 Vol. 33 (6): 555-558 [Abstract] ( 497 ) HTML (1 KB)  PDF (338 KB)  ( 856 )
559 Weak Periodic Signal Detection Based on a Deformable Lorenz Detection System and the Maximum Lyapunov Exponent
MENG Ling-ling,SONG Yan-jun,WANG Xiao-dong
DOI: 10.3969/j.issn.1000-1158.2012.06.18
A deformable Lorenz chaos detection system is proposed. The system has two kinds of states, chaos state and class period state. The maximum Lyapunov exponent is used to distinguish chaos state from class period state as the quantification basis. It can automatically identify the critical state of chaotic systems and can more accurately determine the presence of weak signals.The chaos detection combines with the cross-correlation detection method to achieve weak periodic signals detection in strong noise. Simulation results show that the system can effectively detect weak periodic signals in strong noise.
2012 Vol. 33 (6): 559-564 [Abstract] ( 436 ) HTML (1 KB)  PDF (623 KB)  ( 457 )
565 Study on the Improvement of Precise Time Synchronization for IRIG-B Code Encoder
ZENG Yi-fan,CHEN Gui-jun
DOI: 10.3969/j.issn.1000-1158.2012.06.19
The important factors which affected the accuracy of time synchronization significantly from both software and hardware perspectives are analyzed. A IRIG-B encoder is designed which typical advantages are simple-structure,low-cost and high-accuracy synchronization. The engineering practice shows that the design completely satisfies the demands of the electric power system.
2012 Vol. 33 (6): 565-568 [Abstract] ( 641 ) HTML (1 KB)  PDF (1599 KB)  ( 597 )
569 A Study on Evalution of Local Time Scale
HUANG Yan,GAO Yuan
DOI: 10.3969/j.issn.1000-1158.2012.06.20
Apparently, whether local time scale runs good depends on how it is close to international standard time UTC, but it is more important that the consistency of the second definition reproduced by local time scale and by standard time UTC. Based on the concept defined by BIPM about International Atomic Time (TAI) and Coordinated Universal Time (UTC), it is proposed that fractional frequency difference and time stability are the technical criteria to evaluate the local time scale. The argument above is proved by data analysis from six worldwide timekeeping laboratories with fractional frequency difference and time stability, and then this dissertation give some specific analysis about the relationship between each laboratory’s time scale generation program and the two indexes.
2012 Vol. 33 (6): 569-571 [Abstract] ( 401 ) HTML (1 KB)  PDF (676 KB)  ( 497 )
572 Development of Vitamin B1 Standard Reference Material in Multivitamin Tables
TIAN Ying,YANG Yi,HUANG Ting,LIU Jun
DOI: 10.3969/j.issn.1000-1158.2012.06.21
A new standard reference material of vitamin B1 in multivitamin tables is developed. The sample preparation involves an acid extraction and centrifugation, LC-IDMS method and LC-UV method verify its value. The method is validated by standard reference material SRM 3280, and accuracy of analysis result is validated by two laboratories further. The standard value of vitamin B1 in multivitamin tables is 2.76mg/g and the expanded uncertainty is 0.22mg/g (k=2).
2012 Vol. 33 (6): 572-576 [Abstract] ( 473 ) HTML (1 KB)  PDF (680 KB)  ( 393 )
577 Weighted Mean for Correlation Data Influenced by Common Components
YUAN Zun-dong,WANG Chi,LIN Yan-dong,LI Yan-hua
DOI: 10.3969/j.issn.1000-1158.2012.06.22
By contrasted with the weighted mean method (WMM) for uncorrelated data, the WMM for a set of correlated data with common components is studied. A simple method with manipuility is presented for estimating the uncertainty of common component of traceability chain. The weights for calculating mean, which are derived, are the uncertainties of only uncorrelated components, not the ones of entire data. The uncertainty of common component for the mean is inherent, which is not decreased with increasing the number of averaged data. It not only influences the weights and thus the mean, but also leads an underestimation for the uncertainty of mean to neglect the influence of the correlation on the weights. Take a pressure comparison for instance, the estimations for the uncertainty of common component are illustrated and their results calculated with different estimated values are given.
2012 Vol. 33 (6): 577-582 [Abstract] ( 522 ) HTML (1 KB)  PDF (390 KB)  ( 430 )
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