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2022 Vol. 43, No. 2
Published: 2022-02-28

 
145 Prospect for Replacement of the Mercury Triple Point and a New Temperature Scale
ZHANG Jin-tao,LIANG Yu,FENG Xiao-juan
DOI: 10.3969/j.issn.1000-1158.2022.02.01
The replacement of the mercury triple point from the set of the defining points consituting the International Temperature Scale ITS-90 is indispensable in correspondence to the prohibition action of mercury from commercial trade. The research with the replacement of the mercury triple point is a hot point in the international thermometry community. Finishing such an objective, the thermometric properties of candidates are required to agree with the levels of the triple point of mercury. In addition, the cost and impact to most of users are acceptable with the replacement, the thermometric technology with the new fixed point(s) is as convenience as the old one. The change for the temperature scale with the replacement has to be addressed for every possibility. The researches on replacing mercury triple point in the international thermometry community are reviewed, and the prospect and suggestions on how to revise the new temperature scale are put forward.
2022 Vol. 43 (2): 145-150 [Abstract] ( 287 ) HTML (1 KB)  PDF (412 KB)  ( 238 )
151 Study on the Feasibility of Interpolation Method of SF6 and CO2 Triple Point Replacement of Mercury Triple Point
YANG Jin-nan,PAN Jiang,SUN Jian-ping,LI Ting,WANG Hong-jun,YU Jiao,RUAN Yi-ming,Wang Guang-yao
DOI: 10.3969/j.issn.1000-1158.2022.02.02
For the temperature range from 83.8058K to 273.16K, the replacement of the mercury triple point by SF6 or CO;2 triple point were theoretically analyzed. Without changing the form of interpolation equation of ITS-90, the changes of the temperature deviation and the propagation uncertainty before and after replacement were discussed. The results show that the equations defined by ITS-90 still have the applicability in the temperature range even when SF6 triple point and CO2 triple point replace Hg triple point. Under the same level of the realization uncertainties of the three fixed points, the propagation uncertainty of Hg, SF6 and CO2 triple points decreases in turn over the whole temperature range. It is predicted that the corresponding temperature primary standard level of NIM has no change when the realization uncertainty of SF6 and CO2 triple points is less than 0.25mK (k=1) and 0.27mK (k=1), respectively.
2022 Vol. 43 (2): 151-156 [Abstract] ( 218 ) HTML (1 KB)  PDF (2043 KB)  ( 133 )
157 Study on the Development and Reproducibility of Bromobenzene Melting Point
YANG Yue,CHEN Le,SUN Jian-ping,LI Ting,HAO Xiao-peng,RUAN Yi-ming
DOI: 10.3969/j.issn.1000-1158.2022.02.03
The apparatus of bromobenzene melting point is developed for the on-site calibration of platinum resistance thermometers. The supercooling characteristics and melting point of bromobenzene are investigated. In addition, the methods of curve fitting and tangent intersection are compared for melting point temperature determination. Finally, the practicability of bromobenzene melting temperature plateau for the on-site calibration is analyzed and some recommendations for the use of bromobenzene melting point are also put forward. The experiments show that when the holding temperature for the bromobenzene before freezing procedure is closer to its freezing point temperature, the degree of the supercooling is smaller. During the melting procedure, when the holding temperature is warmer, the heating rate becomes larger, the width of the melting curve becomes wider and the maintenance time of the melting temperature plateau becomes shorter; When the holding temperature during melting procedure is set to -30℃, the melting plateau of bromobenzene can last for more than 6hours. By caluculation, the reproducibility of the inflection point is better than 2.5mK, and the average melting point of bromobenzene is -30.8301℃, which can meet the demand of on-site calibration requirements of industrial platinum resistance thermometer.
2022 Vol. 43 (2): 157-162 [Abstract] ( 189 ) HTML (1 KB)  PDF (2179 KB)  ( 201 )
163 Development of Vacuum Gallium Fixed-point Blackbody
SONG Jian,HAO Xiao-peng,HU Chao-yun,ZHOU Jing-jing,YANG Yan-long,LIU Yang,XIE Chen-yu
DOI: 10.3969/j.issn.1000-1158.2022.02.04
The vacuum gallium fixed-point blackbody radiation source is developed to meet the requirements of radiometric calibration on the infrared remote sensing payload and achieve effective traceability of radiation values to ITS-90. The diameter of the blackbody cavity opening is 25mm, the depth of the cavity is 220mm. The cavity is coated with high emissivity coating. The emissivity of the blackbody is calculated to be 0.9999. The repeatability of the gallium fixed-point phase change plateau is measured under vacuum, the result is 4.4 mK. The stability of the plateau is better than 2 mK. The radiance temperature of the blackbody is measured, and the average radiance temperature in the wavelength range of 8~16 μm is 302.905 K. the influence of the circulating fluid temperature on the plateau and the radiance temperature of blackbody is studied. The combined standard uncertainty of the gallium fixed-point blackbody is analyzed, the result is 0.014K.
2022 Vol. 43 (2): 163-168 [Abstract] ( 230 ) HTML (1 KB)  PDF (2105 KB)  ( 169 )
169 Study on Reproducibility and Assignment of Ga-In Eutectic Fixed Point
WANG Cheng-ke,ZHOU Jing-wei,WANG Hong-jun,SUN Jian-ping,LI Ting,RUAN Yi-ming
DOI: 10.3969/j.issn.1000-1158.2022.02.05
The application of secondary fixed point thermometers to temperature calibration has become an important method to reduce the uncertainty of temperature transmission. Focusing on Ga-In binary alloys, aiming at high reproducibility, the development of large-size fixed-point containers and the process of fixed-point infusion are introduced in detail, and the verification experiments on the reproducibility of fixed-points and the excessive gallium temperature plateau of sub-mixture ratio are carried out. The performance of Ga-In fixed point is evaluated and analyzed by three methods of the phase transition temperature determination including the tangent intersection method, the mean value method, and the polynomial fitting method, and then the Ga-In fixed point phase transition temperature is assigned using three standard platinum resistance thermometers. The results show that the Ga-In eutectic fixed point temperature plateau can last for more than 20hours, and the experimental reproducibility is better than 0.15mK. The fixed point phase transition temperature of Ga-In eutectic determined with the tangent intersection method is 15.6494℃, the expanded uncertainty is 0.76mK (k=2).
2022 Vol. 43 (2): 169-175 [Abstract] ( 217 ) HTML (1 KB)  PDF (2258 KB)  ( 272 )
176 Exploration of Bi-In-Sn Alloy Melting Temperature Plateau Optimization
RUAN Yi-ming,LING Zhong-qian,LI Ting,SUN Jian-ping,WANG Hong-jun,YIN Yue,YANG Jin-nan
DOI: 10.3969/j.issn.1000-1158.2022.02.06
In order to improve the high-precision measurement level of infrared remote sensing, exploring and developing secondary fixed points suitable for the infrared remote sensing temperature measurement range has become an important method to improve the accuracy of on orbit temperature calibration. Aiming at the temperature range (190~350K) involved in the field of infrared remote sensing, Bi-In-Sn ternary alloy fixed point was developed. To improve the reproducibility level of ternary alloy temperature plateau, the ternary alloy fixed point was preproccessed by the pre-melting method, and the effects of different thermal conditions on the ternary alloy temperature plateau were analyzed to obtain the reproduction method suitable for the ternary alloy fixed point. The results show that the reproducibility level of the fixed-point temperature plateau can be optimized through the proper preheating and pre-melting method. The melting temperature plateau of Bi-In-Sn alloy fixed point developed lasts for more than 7 hours, and the reproducibility is better than 1.3mK; by assigning the eutectic point of Bi-In-Sn, the temperature is 333.7318K and the expanded uncertainty is 3.0mK (k=2).
2022 Vol. 43 (2): 176-183 [Abstract] ( 205 ) HTML (1 KB)  PDF (3034 KB)  ( 162 )
184 Research on the Decomposition Mechanism of PtO2 in Low-oxygen Atmosphere
ZHU Tian-meng,PAN Jia-rong,SUN Jian-ping,LI Ting,LI Xu,WANG Cheng-ke
DOI: 10.3969/j.issn.1000-1158.2022.02.07
High-purity platinum wires are used as the sensing elements of standard platinum resistance thermometers, the oxidation and decomposition mechanism affects the stability of the thermometers. Differential calorimetry scanning and X-ray photoelectron spectroscopy are used to analyze the decomposition process of two types of platinum oxides PtO2 and PtO in low oxygen atmosphere. The results show that the decomposition temperature of the two oxides is obviously dependent on the partial pressure of oxygen. At the partial pressure of 10kPa, PtO2 is basically completely decomposed into Pt and PtO at 570℃. At the oxygen partial pressure of 3kPa, the initial decomposition temperature of PtO;2 is about 520℃, and a large amount of Pt is decomposed above 565℃. When the temperature reaches 585℃, the decomposition rate of PtO2 into Pt is the fastest. The research results can provide data reference and theoretical support for the improvement of platinum resistance thermometers manufacturing process and metrological verification procedures.
2022 Vol. 43 (2): 184-190 [Abstract] ( 206 ) HTML (1 KB)  PDF (3800 KB)  ( 142 )
191 The Research on Construction the High Precision Au/Pt Thermocouple and its Stability of Thermoelectric Character
ZHENG Wei,TANG Lei,XIANG Ming-dong
DOI: 10.3969/j.issn.1000-1158.2022.02.08
The stability of thermo-electric character in long term application of Au/Pt thermocouple, which is fabricated by a pure golden wire and a platinum wire, is a key to high accurate performance to in temperature measurement.Firstly, the thermo-elements were cut, cleaned, annealed, welded. Then, the thermo-elements were assembled to the thermocouples and were tested. The stability of whole thermocouples was proved within ±0.02℃ at Ag freezing point calibration, after ageing time of thermocouples was summed up to about 700h at temperature up to 965℃.The thermocouple measurement junction was constructed in three different ways: traditional type, mini-coil type and U shape type, the experiment results showed that the short-term stability is better for mini-coil type compare to U shape type applied to thermocouple measurement junction connection.
2022 Vol. 43 (2): 191-195 [Abstract] ( 217 ) HTML (1 KB)  PDF (1281 KB)  ( 416 )
196 Triple Point of Water Cells with Metal Containers
QIU Ping,YAN Xiao-ke,WANG Hong-jun,WANG Ning,LIU Wei,LIANG Yu
DOI: 10.3969/j.issn.1000-1158.2022.02.09
The tripe point of water (TPW) is the most important defining fixed point in the International Temperature Scale of 1990 (ITS-90), and its realization uncertainty is propagated the whole temperature scale. At present, different freezing methods are adopted to form uniform ice mantles in the borosilicate glass or quartz TPW cells to realize the TPW. Because the ice bridges can happen during the freezing procedure, which can rupture the cells. In order to solve the problem, the TPW cells with metal containers are developed. Using the principle of spontaneous phase transition of high purity, the TPW is automatically realized with a liquid bath. Comparison between the metal-cased cells and the borosilicate glass cell confirmed that the TPW cells with metal containers can meet the requirements for calibration of the standard platinum resistance thermometers and check for the other temperature sensors during the calibration intervals. The experimental results show that the temperature differences between the four metal cased cells and the conventional borosilicate glass cell are within 0.04mK.
2022 Vol. 43 (2): 196-200 [Abstract] ( 254 ) HTML (1 KB)  PDF (1080 KB)  ( 146 )
201 Experimental Study on Scaling Methods of High Accuracy Digital Thermometer Measurement Results
JIN Zhi-jun,CHEN Wei-xin,ZHANG Jun,ZENG Yong-chun,LIU Wei
DOI: 10.3969/j.issn.1000-1158.2022.02.10
The platinum resistance temperature sensor uses CVD equation, ITS-90 international temperature scale and polynomial equation for indexing, and uses high-precision digital thermometer to display the measurement results of different methods, so as to analyze the influence of different scaling methods on the measurement results of high-precision digital thermometer. The experimental research is carried out at -60~300℃. The results show that the scaling method has a certain influence on the measurement results. Under the condition of high-precision measurement, the stability and accuracy can be improved by selecting the method. The research of scaling method should be based on the stability of platinum resistance temperature thermometer and good accuracy of electrical measuring equipment.
2022 Vol. 43 (2): 201-204 [Abstract] ( 209 ) HTML (1 KB)  PDF (1060 KB)  ( 185 )
205 High Accuracy Temperature Indicators Calibration by Master Meter Method
LIU Wei,LIANG Yu,ZHAO Jing,KANG Hui-wen,JIN Zhi-jun,QIU Ping
DOI: 10.3969/j.issn.1000-1158.2022.02.11
A method of calibrating high accuracy temperature indicators using the combination of DC comparator bridges for measuring temperatures and DC resistance box as the standard device was proposed, which referred to the method of calibrating the instrument using master meter method in the field of flow and electrical measurement. The method was used to calibrate a high accuracy temperature indicator, and the measurement uncertainty was analyzed. The calibration results showed that the combined standard uncertainty of temperature indication deviation was 0.5~0.7mK in the range of -195℃ to 660℃. The accuracy of the standard instrument used in this method was higher than that of other existing calibration methods, and it could also be applied in a wider range of ambient temperature.
2022 Vol. 43 (2): 205-209 [Abstract] ( 234 ) HTML (1 KB)  PDF (523 KB)  ( 164 )
210 Study on In-situ Calibration of Precision Platinum Resistance Thermometer Based on Micro Gallium Fixed-point
WANG Bo-yang,ZENG Fan-chao,FU Cheng-yu,HUANG An-yi,SUN Jian-ping
DOI: 10.3969/j.issn.1000-1158.2022.02.12
Based on the transfer technology of fixed-point temperature scale, a precision platinum resistance thermometer which can be calibrated in-situ at the melting point of gallium was designed and the characteristics of the micro fixed-point phase change temperature level were analyzed experimentally. The experimental results show that the maximum duration of the fixed temperature plateau is 1.2h, the stability of the plateau is better than 2.8mK and the reusability is better than 2.3mK within 20min. There is a linear relationship between the micro fixed-point temperature level and the heating temperature, and as the heating temperature increases, the temperature plateau value of the fixed-point increases, and the fixed-point temperature level at different heating temperatures can be calculated by fitting formula.
2022 Vol. 43 (2): 210-214 [Abstract] ( 210 ) HTML (1 KB)  PDF (1485 KB)  ( 180 )
215 Design Method of High Gas Temperature Sensor Based on Double Heat Conduction Equation
ZHAO Jian
DOI: 10.3969/j.issn.1000-1158.2022.02.13
A practical high gas temperature sensor is introduced, including overall structure design, sensitive element design, ceramic insulator selection, shield design and shell design aimed at a certain working condition. During key structure and size design of the shield, a model based on double heat conduction is put forward by which design method of high gas temperature sensor is optimized, then verification test of the design result has been carried out in the hot wind tunnel. Test result shows that the designed temperature sensor has a relative measuring error of 0.2%~1.3% and can be used for precise measurement of high gas temperature in aviation and aerospace fields.
2022 Vol. 43 (2): 215-221 [Abstract] ( 197 ) HTML (1 KB)  PDF (1325 KB)  ( 273 )
222 Influence Analysis of Working Condition Carameters of Single Screen Multipoint Air-flow Temperature Sensor in Field Calibration
WANG Yu-fang,DONG Su-yan,ZHAO Jian,LIU Chong-yang
DOI: 10.3969/j.issn.1000-1158.2022.02.14
By means of numerical simulation, the single screen multi-point air flow temperature sensor in the combustion chamber test environment is simulated, the temperature field and flow field environment are changed, and the influence laws of different working conditions parameters such as total inlet temperature, total inlet pressure and Mach number on the measurement results of the single screen multi-point air flow temperature sensor are analyzed and verified by experiments. The numerical simulation results show that under the combustion chamber test environment, the temperature measurement deviation of the single screen multi-point air flow temperature sensor increases with the increase of the total incoming flow temperature. For each increase of 1000K, the temperature measurement deviation increases by about 2K; with the increase of the total incoming pressure, the temperature measurement deviation decreases by about 1K for every 100kPa increase; it decreases with the increase of incoming Mach number, for each increase of 0.1, the temperature measurement deviation decreases by 0.7K. The above conclusions provide a reference for the field calibration of gas flow temperature parameters in combustion chamber test.
2022 Vol. 43 (2): 222-227 [Abstract] ( 226 ) HTML (1 KB)  PDF (3140 KB)  ( 180 )
228 Research on Temperature Uniformity of the Calibration Furnace with Multiple Calorifiers
LIU Hong-yan,ZHANG Shuai-xing,XU Zhen-zhen,ZHANG Kai-xing,ZHANG Jun
DOI: 10.3969/j.issn.1000-1158.2022.02.15
In the process of thermocouple calibration, there are some problems such as temperature control lag, long constant temperature time, electric leakage and furnace tube bending caused by using the traditional thermostatic block for calibration furnace. Therefore, a calibration furnace with multiple calorifiers which can meet the requirements of relevant specifications without the temperature uniformity of the thermostatic block has been developed to improve the calibration efficiency. Firstly, according to JJF 1184-2007 Testing Specifications for Temperature Uniformity in Thermocouple Calibration Furnaces, the temperature uniformity of the traditional calibration furnace with single calorifier equipped with the thermostatic block and the calibration furnace with multiple calorifiers without the thermostatic block are tested respectively. Secondly, the two kinds of temperature uniformity are compared and verified by thermocouple indication error test. The results show that in the temperature range of 400~1000℃, the calibration furnace with multiple calorifiers without the thermostatic block is superior to the traditional calibration furnace with single calorifier equipped with the thermostatic block in the axial temperature uniformity, radial temperature uniformity, thermocouple indication error and other tests.
2022 Vol. 43 (2): 228-234 [Abstract] ( 187 ) HTML (1 KB)  PDF (2163 KB)  ( 169 )
235 Research on Hot Spot Temperature Monitoring Technology of Transformer Winding
JIA Dan-ping,ZHAO Lu,HUANGFU Li-ying
DOI: 10.3969/j.issn.1000-1158.2022.02.16
Design a temperature monitoring system based on fiber Bragg grating (FBG) to realize real-time monitoring of the hot spot temperature of transformer windings. Introduce the principle of fiber grating temperature measurement, and use the Maxwell and Fluent modules in Ansys to simulate the electromagnetic field-fluid field-temperature field of the transformer to obtain specific information of the hot spot, so that the position of the fiber grating sensor can be reasonably placed during actual measurement. Use the FBGA demodulation module to process the detected optical signal and complete the hardware construction. On the computer, the DLL function of the dynamic link library is called through the Labview software to complete the design of the host computer, which can realize the display of temperature and wavelength, and alarm when the temperature exceeds the threshold set by the user. Finally, the hardware part and the software part are connected to complete the construction of the entire temperature measurement platform.The calibration experiment and error analysis experiment are carried out, the fitting relationship between the central wavelength of FBG and temperature is obtained, and the feasibility of the temperature measurement platform is verified.
2022 Vol. 43 (2): 235-241 [Abstract] ( 170 ) HTML (1 KB)  PDF (3071 KB)  ( 512 )
242 Modeling and Simulation Analysis of Transformer Hot Spot Temperature Based on Multi Physical Field Coupling and Temperature Rise Characteristics
XU Jing,LIU Shu-xin
DOI: 10.3969/j.issn.1000-1158.2022.02.17
The research on the temperature rise characteristics of transformer, especially the hot spot temperature measurement, is helpful to master the operation state of transformer, so as to avoid the occurrence of thermal fault and guide the dynamic capacity increase of transformer. Aiming at the improvement of the existing hot spot temperature calculation method, a temperature rise model of oil immersed transformer based on multi physical field coupling is proposed. Taking 500kV oil immersed transformer as an example, the thermal characteristics of transformer are analyzed by using the principle of energy conservation. The mathematical and physical models of temperature field and flow field of transformer are established. The temperature rise characteristics, physical parameters and material characteristics of transformer are analyzed. The fluid solid thermal coupling temperature field calculation method is used for simulation calculation. Through simulation calculation and analysis, it has a deeper understanding of the specific distribution position and value of hot spot temperature.The accuracy of the mentioned method is 4% higher than that calculated by empirical formula, it provides a new calculation idea for the calculation of transformer hot spot temperature.
2022 Vol. 43 (2): 242-249 [Abstract] ( 278 ) HTML (1 KB)  PDF (3201 KB)  ( 570 )
250 Study on Temperature-discharge Rate Coupling Accelerated Life Model of Ternary Lithium Battery
DING Peng-fei,SUN Jian,XU Hong-wei
DOI: 10.3969/j.issn.1000-1158.2022.02.18
To study the insufficient effect of accelerated life test of ternary lithium battery, an accelerated life model based on Arrhenius model with ambient temperature as a single acceleration factor is established. The accelerated life model is based on the empirical model of battery life decline under the coupling of ambient temperature-discharge rate. The expermental results show that the acceleration effect is limited when the ambient temperature is a single factor. Compared with temperature and discharge rate at 25℃ and 1C, the average number of cycles is shortened by 290 times at 50℃ and 1C, 510 times at 50℃ and 3C, and 710 times at 50℃ and 5C. The coupling of temperature and discharge rate can effectively shorten the times of charge and discharge compared with a single ambient temperature. The coupled accelerated life model is used to infer the battery life characteristics under low or normal level conditions through high-level factors.
2022 Vol. 43 (2): 250-255 [Abstract] ( 236 ) HTML (1 KB)  PDF (1350 KB)  ( 496 )
256 3D Temperature Model Reconstruction Based on Fusion of Visible and Thermal Images
ZHANG Yuan-hui,XU Bai-rui,ZHU Jun-jiang,SUN Jian
DOI: 10.3969/j.issn.1000-1158.2022.02.19
Thermal cameras, which can detect thermal emissions and produce images of radiation, are widely used in various industrial applications in recent years. However, without intuitive geometric information, it is difficult to identify objects on thermal images when adjacent sampling areas have the same temperature. To solve the above problem, a method to reconstruct a 3D thermal model by fusing visual geometry and temperature information is proposed. Firstly, a calibration board is used to calibrate the visible camera and thermal imager. Then, based on camera poses acquired by structure from motion, semi-global matching is used to obtain a coarse estimate of depth maps which are optimized by a refinement method combining geometry and shading term. Finally, with the help of camera parameters and calibration information, mutual information is used to achieve the registration between the visible and the thermal image, and the 3D temperature model is reconstructed through the depth maps.
2022 Vol. 43 (2): 256-263 [Abstract] ( 327 ) HTML (1 KB)  PDF (4034 KB)  ( 649 )
264 Design and Uncertainty Evaluation for New Blackbody Source
LIU Pei,YANG Xue,WANG Jing-hui,HU Die,ZHANG Xin,XU Biao
DOI: 10.3969/j.issn.1000-1158.2022.02.20
In order to enhance the heat transfer between the blackbody cavity and the heat carrier, a new design of cavity blackbody source with passive spoiler is proposed. With the newly designed micro-disturbance structure on the outer wall of the cavity, the thermal boundary layer of the working fluid is disturbed to destroy and regenerate, so the heat transfer is enhanced by the principle of high heat transfer intensity in the initial section of the thermal boundary layer. The new design can not only improve the heat transfer coefficient, but also increase the heat transfer area, which can reduce the time required for the cavity and the heat carrier to achieve thermal balance. The experimental study and uncertainty evaluation of the new blackbody radiation source of the ear thermometer are carried out. The results show that the expanded uncertainty of the new design cavity blackbody is U=0.05℃(k=2), and the equilibration time can be reduced by more than 15%.
2022 Vol. 43 (2): 264-267 [Abstract] ( 178 ) HTML (1 KB)  PDF (795 KB)  ( 221 )
268 Analysis of Results about the Comparison of Marine Temperature Calibration
GAO Zhan-ke,YUAN Ling-ling,JIANG Fan
DOI: 10.3969/j.issn.1000-1158.2022.02.21
Marine temperature measuring instrument is the most important instrument in marine survey, observation and monitoring business. It needs to carry out measurement calibration to ensure the accuracy and reliability of measurement results, eliminate the systematic error caused by drift. In order to evaluate the consistency of the calibration results of marine temperature measuring instrument among laboratories in different countries, the marine metrology and calibration laboratories of three countries in the Asia Pacific region have carried out the comparison of marine temperature calibration. The results of the comparison are consistent, and the deviation of the measurement results of each reference laboratory is within the acceptable range.
2022 Vol. 43 (2): 268-273 [Abstract] ( 239 ) HTML (1 KB)  PDF (1466 KB)  ( 446 )
274 Review on the Cavity Ring-down Spectroscopy for Greenhouse Gas Monitoring
MA Lu-yao,LIN Jun,ZHANG Liang,LIN Hong,FENG Xiao-juan,XU Hong,REN Ge,ZHANG Jin-tao
DOI: 10.3969/j.issn.1000-1158.2022.02.22
The impact of global climate change to human life has been widespread concern in the world. Greenhouse gas is one of the key factors that affect the climate change. Therefore, to limit and reduce the emissions of greenhouse gases has become an important issue in the world. Most of the greenhouse gas concentration are in10-6 (part per million) level. Because of its low concentration and large difference in gas molecular structure, the traditional method is difficult to obtain higher precision in concentration monitoring. Cavity ring-down spectroscopy (CRDS) is one of the key techniques to solve this problem. In this paper, the research progress of greenhouse gases monitoring by cavity ring-down spectroscopy is reviewed, especially the frequency-stabilized CRDS which now can achieve the best signal-to-noise ratio and detection limit. The future development of cavity ring-down spectroscopy is prospected.
2022 Vol. 43 (2): 274-280 [Abstract] ( 339 ) HTML (1 KB)  PDF (861 KB)  ( 1109 )
281 Study on Estimating All Carbon Sink Resources of Zhengzhou Based on Statistics
LI Yuan-qing,ZHANG Xiao-dong,HU Na,REN Ge,LI Mei-ling,ZHAI Zhong-xi,LIN Hong
DOI: 10.3969/j.issn.1000-1158.2022.02.23
Located in North China Plain, Zhengzhou has a large area of farmland, accounting for about 44.4%, while forest and urban green area are relatively small. Currently, the forest resources are the primary target of carbon sink estimation in China, while urban green and farmland resources usually have been ignored. In order to completely consider all carbon sink resources in Zhengzhou, the carbon sink of forest (e.g. arbors, bamboo, shrub, economic forests), farmland (e.g. wheat, corn, vegetables, fruits) and urban green (arbors and shrub) had been estimated in the study, using the statistics of Zhengzhou. The results showed that farmland carbon sink in Zhengzhou was about 1.46million tons, and wheat and corn, as the main crops, contributed the most (approximately 73.19%). Man-made forest (e.g. poplar, paulownia) had the maximum contribution to the forest carbon sink, accounting for 48.81%, and the total forest carbon sink in Zhengzhou was about 0.22million tons. The urban green carbon sink was about 0.22million tons. The carbon sink of street trees, such as goldraintree, ginkgo, sycamore, were the biggest part of the urban green carbon sink in Zhengzhou, which was approximately 51.16%. Therefore, when estimating carbon sink in Zhengzhou, the carbon sink result would be seriously underestimated, if the farmland and the urban green carbon sink resources were ignored.
2022 Vol. 43 (2): 281-286 [Abstract] ( 278 ) HTML (1 KB)  PDF (1539 KB)  ( 380 )
287 Measurement of Water Vapor Linear Intensity Based on Cavity Ring-Down Spectroscopy
MA Lu-yao,Ma Ruo-meng,XU Hong,FENG Xiao-juan,ZHANG Jin-tao,LIN Hong
DOI: 10.3969/j.issn.1000-1158.2022.02.24
With the rapid development of the semiconductor chip industry, the requirements for electronic gases have gradually increased. Trace moisture in the semiconductor processing environment will seriously affect the yield and reliability of the chip. Cavity ring-down spectroscopy is a trace gas measurement method with high sensitivity and accuracy developed in recent years, and the linear intensity is an important parameter for the measurement of spectroscopy. In order to measure the trace humidity, an optical cavity ring-down spectroscopy system for trace humidity measurement was established. The absorption spectra with the center frequencies at 7171.10491cm-1 and 7177.6565cm-1 were measured. The linear intensity was obtained by HTP (Hartmann-Tran profile) linear fitting. The relative standard uncertainty of the measurement result is better than 1.8%. Compared with HITRAN, HITEMP and GEISA databases, the relative deviation is less than 6%.
2022 Vol. 43 (2): 287-292 [Abstract] ( 214 ) HTML (1 KB)  PDF (2159 KB)  ( 551 )
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