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2011 Vol. 32, No. 2
Published: 2011-03-22
 
97 Study and Establishment of the National Standard ofthe Ultra-low frequency Vibration
YU Mei,HE Wen,LIU Ai-dong,MA Ming-de,YANG Li-feng,ZUO Ai-bin,HU Hong-bo
DOI: 10.3969/j.issn.1000-1158.2011.02.01
According to the research status and application requirements for ultra-low frequency vibration standard at home and abroad,the national standard device for vibration magnitude and phasewas studied and established.The ultra-low frequency range is 0.002 Hz to 160 Hz.The maximum peak-to-peak value of amplitude is 1m.The maximum load is 30 kg.The distortion of acceleration waveform is less than 1%.The structure composition of the device and the key technologies solved are introduced.The design project of the long-stroke horizontal vibrator,the negative-feedback control technology,the pipeline dragging synchronous tracking control system and the laser vibration measuring system are described.The main technical specifications of the standard device and the results of comparison experiment are given.The establishment of the national standard device can solve the quantity traceability problem of the ultra-low frequency vibration metrology.
2011 Vol. 32 (2): 97-100 [Abstract] ( 675 ) HTML (1 KB)  PDF (545 KB)  ( 1405 )
101 Sensitivity Model of Micro-machined Accelerometers Based on the Deviation of Comb Finger Gaps
DAI Qiang,YU Qi,QIAN Ke-qiang,ZHOU Wei
DOI: 10.3969/j.issn.1000-1158.2011.02.02
To cope with sensitivity deviation of capacitive micro-accelerometers brought by micro-machined process error in comb finger gaps, a sensitivity model is proposed based on probability theory and close loop capacitive micro-accelerometer mechanism. It is indicated that, by the model, when the accelerometers gaps dimensions are from 3.7 to 4.6 μm due to micro-machined process and meanwhile, effective voltages on the fixed electrodes are 2.3V, 5.1V and 8.3V respectively, sensitivities of the accelerometers will be in 120~195 mV/gn, 55~85 mV/gn and 32~51 mV/gn. Furthermore, a batch of bulk silicon accelerometers are tested. With the same effective voltages, the sensitivity test results are in 119.3~179.9 mV/gn,53.8~81.1 mV/gn and 33.0~49.8 mV/gn. Hence, the model and test results are relatively close to each other. Through the model, the relationship between sensitivity and comb finger gap process error has been revealed, which might hopefully serve as a reference for micro-accelerometer design and optimizing of the process.
2011 Vol. 32 (2): 101-105 [Abstract] ( 617 ) HTML (1 KB)  PDF (489 KB)  ( 462 )
106 Impact Monitoring of CFRP with Fiber Bragg Grating Sensor
LU Ji-yun,LIANG Da-kai,LU Guan,ZENG Jie
DOI: 10.3969/j.issn.1000-1158.2011.02.03
Fiber Bragg grating (FBG) is applied for the impact-related experiments of carbon fiber reinforced plastics (CFRP) and impact monitoring system is built. FBG sensors are stuck on the CFRP to setup network, impact response signal measured by same FBG is analyzed for different impact location. The resonant frequency of CFRP is 53Hz and 100Hz, which amplitude of different resonant frequency is changed with location of impact. When CFRP laminate is impact, impact response signals using FBG sensors network is analyzed by wavelet packet decomposition and wavelet packet energy spectrum is obtained. The results show the sixth order wavelet packet energy monitored by FBG sensors change obviously and the energy not only is related to distance from impact point to FBG sensor but also is related to the angle between impact point and axial of FBG sensor. The research provides a practical reference in dynamic monitoring of CFRP dynamic monitoring field.
2011 Vol. 32 (2): 106-109 [Abstract] ( 632 ) HTML (1 KB)  PDF (595 KB)  ( 431 )
110 Study on Vertical Liquid Petroleum Tank Volume MeasurementMethod Based on Data Cloud Analysis
WANG Jin-tao,LIU Zi-yong,ZHANG Long,GUO Li-gong,BAO Xue-song,TONG Lin
DOI: 10.3969/j.issn.1000-1158.2011.02.04
A vertical tank volume measuring method based on data cloud analysis is researched. The distance measurement by phase and angular measurement with optical grating is applied to acquire coordinates of data cloud in each plate under the control of servo system, and the permitted error of point location is 2mm. Iterative method and least square algorithms were used to process the measured data and deduce equivalent radius of each loop. In comparison experiment, one 1000m3 vertical tank is used as test object. The largest measured radius difference between the new laser method and strapping method (international arbitrary standard) is 2.8mm.
2011 Vol. 32 (2): 110-103 [Abstract] ( 573 ) HTML (1 KB)  PDF (742 KB)  ( 646 )
114 Analysis on the Uncertainty in Volume Measurement of Tanker Containers
YAN Feng-xia,FU Qing-xi,SHAO Xue-jun,ZHOU Bao-long
DOI: 10.3969/j.issn.1000-1158.2011.02.05
The volume of arc tank shell tanker containers are measured using geometric method and volumetric comparison method. The uncertainty in volume measurement of the tanker containers are evaluated on the basis of the establishment of different mathematic models and the values are 4×10-3 (k=2) and 2×10-3 (k=2) respectively for geometric method and volumetric comparison method. To test the result of evaluation, the transfer-comparison method is adopted. By calculation and analysis of the test data, the validity and rationality of the evaluation is validated.
2011 Vol. 32 (2): 114-117 [Abstract] ( 381 ) HTML (1 KB)  PDF (266 KB)  ( 465 )
118 Research on Compensation of the Installation Eccentricity in the Gearwheel Measurement
GUO Jing-bin,ZHANG Da-sha,ZHANG Ji-cheng,ZHOU Guang-cai
DOI: 10.3969/j.issn.1000-1158.2011.02.06
It has a direct effect on profile deviation and pitch deviation for the installation eccentricity in the measurement of the gearwheel．According to the relationship between installation eccentricity and meshing line increment,the mathematical model of the meshing line increment which is generated by the installation eccentricity is established．The mathematical models of compensation on profile deviation,pitch deviation and cumulative pitch deviation are presented．Through the experiment of measuring gear involute master and master gear installed eccentrically,the validity of compensation models are verified．Finally,applications of compensation models are given.
2011 Vol. 32 (2): 118-122 [Abstract] ( 502 ) HTML (1 KB)  PDF (925 KB)  ( 749 )
123 Self-calibration System for the Value Drifts of CCD Autocollimator
ZHANG Jun-jie,WANG Zhen,LI Zheng-yang,ZHANG Jun-xiu
DOI: 10.3969/j.issn.1000-1158.2011.02.07
When the digital autocollimator is put into use directly, its indications will drift and beat under the influence of environmental conditions such as air streams and the increasing heat of equipment itself, which leads to the measuring errors greatly increased and the measurement results could not return to zero. A fixed mirror which is added as a reference mirror makes the differential measurement with a working mirror and forms a self-calibration system, which could effectively reduce errors. The value of drift is 0.03″ in two hours when working mirror is only used and it reduces to 0.01″ after the adoption of a self-calibration system; the standard deviation of samples is 0.0911″ and it reduces to 0.0574″ after the self-calibration. The self-calibration system of differential mirror could effectively reduce the indication errors of CCD autocollimator and plays an efficient role in reducing the indication beat. It is an effective way for the system to reduce the drift and beat of the equipment caused by both the environmental conditions and the equipment themselves.
2011 Vol. 32 (2): 123-125 [Abstract] ( 570 ) HTML (1 KB)  PDF (558 KB)  ( 419 )
126 Etched Phase Shift Fiber Bragg Grating Based Refractive Index Sensing
QIU Yue,CHEN Zhe-min
DOI: 10.3969/j.issn.1000-1158.2011.02.08
A fiber Bragg grating etched by HF solution is applied for refractive index sensing. The dispersion relation equation of fiber is numerically resolved. The reflected spectrum of the fiber grating during etching and sensing is theoretically obtained. The result is applied to design an optimum etching process, and a phase shift fiber Bragg grating is fabricated and applied to measure refractive index of surround solution. The fiber Bragg grating is partial and localized etched to be a phase shift fiber Bragg grating. According to the character of phase shift fiber Bragg grating, a modulation method based on reflected power is developed, the modulation system is convenient and immune to temperature change.
2011 Vol. 32 (2): 126-130 [Abstract] ( 424 ) HTML (1 KB)  PDF (382 KB)  ( 423 )
131 Parallel Implementation of Intelligent Optimization Platform and Application in Optical Design
ZHANG Huo-ming,GAO Ming-zheng,ZHANG Xiao-fei,JIN Shang-zhong
DOI: 10.3969/j.issn.1000-1158.2011.02.09
A intelligence optimization algorithms is integrated to construct an intellectual optimization platform, including particle swarm optimization algorithm, ant-colony optimization algorithm, genetic algorithm, simulated annealing algorithm, chaos algorithm and complex algorithm. The platform is consisted of four modules: input module of optimization problem, adjusting module of optimization algorithm, optimization calculation module and output module of optimization results. The optimization platform is applied in the optimization design of RGB LED which is mixed with white light, to optimize the luminous efficiency and the color rendering index of the hybrid lighting module. The calculating methods of luminous efficiency and color rendering index of the hybrid lighting modules is put forward.
2011 Vol. 32 (2): 131-136 [Abstract] ( 422 ) HTML (1 KB)  PDF (434 KB)  ( 426 )
137 Theory and Design for Blackbody Cavity Radiation
LI Wen-jun,Sun Jian,Zhou Chao,Liu Zhao-ming,Huang De-ming
DOI: 10.3969/j.issn.1000-1158.2011.02.10
The integrating equation theory as an important part of radiation theory for blackbody cavity and its development are reviewed.A new type of design for blackbody cavity is presented.The cavity possesses with a double layer structure which is connected to liquid bath to keep the fluid flows in a circle in it.This structure greatly improves isothermal condition around blackbody cavity.A high radiation and heatproof coating is used for inner wall of the cavity, which has very good diffuse radiation characteristics. The effective emissivity of the designed blackbody cavity is up to 0.998.
2011 Vol. 32 (2): 137-140 [Abstract] ( 545 ) HTML (1 KB)  PDF (360 KB)  ( 1172 )
141 Study on the Characteristics of Electrostatic Sensor Inserted into Pipes
KAN Zhe,SHAO Fu-qun,LI Cheng-zhi,LI Qing-hua
DOI: 10.3969/j.issn.1000-1158.2011.02.11
The electrostatic sensor inserted into pipes is successfully applied for measuring the parameters of the gas-solid two phase flow and ensuring the safety during the gas-solid two phase flow convey.Through establishing the mathematical model of the probe, the inserted depths,spatial filter characteristics and the spatial sensitivity characteristics of the inserted probe are discussed. The situation which the particles position effect on the induced charges of the probe, and the relation between the inserted depth of probe and the signal amplitude measured are obtained. For the continuous flow of solid particles inserted probe,the optimum inserted depth is 1/2 of the pipe diameter and the probe has low-pass filter characteristic.The expression about the solid particle velocity and the measured signal cut-off frequency is obtained during deducing spatial filter characteristic of the probe with probe mathematics model.The measured results confirm the spatial filter characteristic and spatial sensitivity characteristic of the probe.
2011 Vol. 32 (2): 141-146 [Abstract] ( 531 ) HTML (1 KB)  PDF (996 KB)  ( 875 )
147 Approach to Piano Pitch Recognition Covering Full Frequency Range
LUAN Ji,NA Wen-bo
DOI: 10.3969/j.issn.1000-1158.2011.02.12
To study piano notes covering full frequency range,and an approach for piano pitch recognition is proposed based on auto-correlation and interpolation. It draws function waves after three-level center clipping auto-correlation computing, and chooses the places of fundamental frequency periods by the way of calculating max value. An interpolation method in parabola is used to modify the places, then the fundamental frequency of signal is estimated by the least square method, and the recognition error for signals with LO-MID fundamental is less than ±1cent. As for signals with high fundamental, it use a method to reduce error based on interpolation for up-sampling. And after that the recognition result is more accurate and reliable, meeting the accuracy requirement effectively.
2011 Vol. 32 (2): 147-151 [Abstract] ( 725 ) HTML (1 KB)  PDF (1031 KB)  ( 1519 )
152 Uncertainty Analysis on the Magnetic System of Joule Balance, a Quantum Mass Standard
HAN Bing,HE Qing,LI Zheng-kun,LI Chen
DOI: 10.3969/j.issn.1000-1158.2011.02.13
Based on the special structure of exciting coils system of Joule balance, the uncertainty sources of the magnetic density in the geometrical center of magnetic field was analysed and evaluated.The relative combined standard uncertainty of magnetic field in ΔH/H was 1.8×10-3 In addition, it was proved that the largest components of uncertainty were due to terms with u(I),which was 1.8×10-3 contribution to relative combined standard uncertainty in ΔH/H.Therefore the high-precision constant-current source was recommended to reduce uncertainty of magnetic field of Joule Balance.
2011 Vol. 32 (2): 152-157 [Abstract] ( 467 ) HTML (1 KB)  PDF (690 KB)  ( 395 )
158 Influence of Magnetic Field on Calibration Process ofInductive Conductivity Sensors
ZHANG Chuan,HU Bo
DOI: 10.3969/j.issn.1000-1158.2011.02.14
A series of experiments were carried out to study the effect of the magnetic interference which from the magnetically-coupled stirring to the electromagnetic induction-type conductivity meter in the routine conductivity, temperature and depth (CTD) calibration. RBR XR-620 (electromagnetic induction-type) and SBE 37 (electrode type) were selected as model in the investigation. All the experiments were carried out in two thermostatic baths for contrasting with each other, one of the thermostatic baths using magnetically-coupled stirring apparatus and the other using mechanical stirring apparatus. The results show that the magnetic filed indeed has an inference to the electromagnetic induction-type conductivity meter.
2011 Vol. 32 (2): 158-161 [Abstract] ( 440 ) HTML (1 KB)  PDF (755 KB)  ( 506 )
162 alibration of Channel Mismatches in Time-interleaved ADCs Based on Multi-Frequency Reference Error Method
ZHANG Hao,SHI Yi-bing,WANG Zhi-gang,ZHU Zhao-xuan
DOI: 10.3969/j.issn.1000-1158.2011.02.15
Aiming at the problem of channel mismatch calibration in time-interleaved ADCs (TIADC), the characteristics of channel mismatch phenomena are firstly analyzed, then system calibration model is built based on reference channel, finally a new calibration approach called multi-frequency reference error method is introduced. This method can efficiently complete effective error compensation by fast frequency calculation and look up table. In addition to that, the applicability and calibration performance of the method in the whole input bandwidth of TIADC are further discussed. The simulation demonstrated that multi-frequency reference error method can improve the SFDR of TIADC beyond 25 dB.
2011 Vol. 32 (2): 162-167 [Abstract] ( 640 ) HTML (1 KB)  PDF (1323 KB)  ( 559 )
168 A Coaxial-to-waveguide Adaptor Calibration Method using an Adjustable Shorter with Unspecified Phases
WU Chang-ying,XIE Chun-jian,WEI Gao,XU Jia-dong
DOI: 10.3969/j.issn.1000-1158.2011.02.16
A technique is described to remove the coaxial-to-waveguide adaptor errors when the reflection coefficient of waveguide device is measured by vector network analyzer.This technique utilizes a matched load and an adjustable shorter with several unspecified phases.And one of the shorted planes is used as reference plane.It is shown that the technique is resistant to the error of the adjustable shorter position and is easy to implement.The efficiency of this technique is verified by measurement data in X band.
2011 Vol. 32 (2): 168-171 [Abstract] ( 497 ) HTML (1 KB)  PDF (863 KB)  ( 395 )
172 Study on Time and Frequency Dissemination by GLONASS
LIANG Kun,ZHANG Ai-min
DOI: 10.3969/j.issn.1000-1158.2011.02.17
The development trend of time and frequency dissemination based on GNSS and the status and future improvement of GLONASS were analyzed. GLONASS time and frequency dissemination was studied and its theory, realization principle, error correction and data processing were described. The basic method of GLONASS time and frequency dissemination was realized, the experiments results were compared to those of GPS time and frequency dissemination were implemented, and the performances were analyzed. The conclusion that GLONASS time and frequency dissemination can be comparable with GPS time and frequency dissemination was acquired.
2011 Vol. 32 (2): 172-177 [Abstract] ( 492 ) HTML (1 KB)  PDF (1999 KB)  ( 620 )
178 Soft-sensor for Product Concentration of Evaporator Based on KPLS
CHAI Qin-qin,YANG Chun-hua,GUI Wei-hua
DOI: 10.3969/j.issn.1000-1158.2011.02.18
Considering the difficulty of keeping the accuracy of on-line product concentration measurement in practical process under scaling or scabbing conditions, Kernel partial least square (KPLS) algorithm is proposed to build soft-sensor model for the product concentration based on the analysis of nonlinear characteristic and factors affecting product concentration of the vertical tube falling-film evaporator. KPLS-based model realizes on-line concentration measurement by effectively extracting nonlinear eigenvector of concentration and relevant detection variables. Simulation results show that the KPLS-based model achieved better performance in accuracy than that in the conventional linear partial least squares-based model, and relative error for production concentration measurement can meet the practical requirements.
2011 Vol. 32 (2): 178-181 [Abstract] ( 501 ) HTML (1 KB)  PDF (609 KB)  ( 422 )
182 The Measurement of the Refractive Index and Concentration of Solutions Based on Long-period Gratings
HU Xing-liu,LIANG Da-kai,ZENG Jie,LU Guan
DOI: 10.3969/j.issn.1000-1158.2011.02.19
The resonant peaks of long-period grating pair are sensitive to external refractive index.According to this characteristic, on-line and real-time measurement of liquids refractive index and concentration can be realized. NaCl and sugar solutions which are of different refractive index are studied. The relationships among refractive index, concentration and resonant peaks are obtained. The experimental results show that the LPGP is sensitive to the external refractive index which is in the range of 1 to 1.4513, when the external refractive index increase, the amplitude of loss peak decrease gradually and the central wavelength has a blue shift.This sensor is quite useful for chemical, pharmaceutical, biological, and process control sensing applications and it has very high practical value.
2011 Vol. 32 (2): 182-186 [Abstract] ( 444 ) HTML (1 KB)  PDF (677 KB)  ( 1216 )
187 Study on Preparation of Low Concentration of Hydrogen Sulfide
HU Shu-guo,YANG Sheng-hui,WU Hai,GAI Liang-jing,LI Meng-yi
DOI: 10.3969/j.issn.1000-1158.2011.02.20
The gas dilution device consisted of mass flow controllers with high-accuracy is developed. It is evaluated by different kinds of gas reference materials and used to dilute hydrogen sulfide reference with low concentration finally.By several tests,a conclusion is that the gas dilution device with good linearity, accuracy and repeatability can be used to prepare hydrogen sulfide with low concentration quickly.
2011 Vol. 32 (2): 187-192 [Abstract] ( 412 ) HTML (1 KB)  PDF (306 KB)  ( 558 )
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