计量科学与技术

High Precision Measuring Method for Micro Gears Basing on White Light Interferometer

SONG Huixu, JIANG Jinzhe, SHI Zhaoyao, YU Bo

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0352

Abstract(30)

HTML (17)

PDF(1)

Abstract:
The prerequisite for achieving high-precision measurement lies in the accurate acquisition of the physical quantities to be measured, and currently high-precision and expensive CNC gear measuring instruments are commonly used. However, the complete tooth profile of micro gear with modulus less than 0.1mm and diameter less than 1mm cannot be measured by traditional contact measurement due to the narrow space width. Optical methods cannot obtain the data near tooth root due to the shield and inclination. In response to this situation, this paper proposes a high precision measuring method for micro gears basing on white light interferometer. Real time monitoring of the tilting degree of micro gear is achieved by the order of appearance of interference patterns, which ensures the accuracy of profile extraction; The center of the gear is determined by the 3D points of the surface, which can effectively improve the gear centering accuracy. This paper focuses on the principle of white light interferometry measurement for micro gears, the leveling model, and the gear error calculation method. The experimental results show that this method provides an effective means for solving the precision measurement of micro gears.

Review of Theoretical and Applied Research on Measurement Uncertainty

TAO Meng, REN Siyuan, LAO Changjuan

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0263

Abstract(33)

HTML (89)

PDF(8)

Abstract:
This article provides a systematic review of the theory, research and application on measurement uncertainty. Firstly, it gives an overall introduction to the historical development. Secondly, the basic principles, latest researches and limitations of several types of mainstream measurement uncertainty evaluation methods are summarized, such as the GUM method, which is the most commonly used evaluation method at present, mainly for the linear or approximate linear measurement models and adopts the method based on the transfer of standardized uncertainty; the Monte Carlo-based measurement uncertainty evaluation method and its derivatives, the proposed Monte Carlo method and the adaptive Monte Carlo method have wider applicability when dealing with complex models; Bayes-based measurement uncertainty assessment method can give full play to the value of the a priori data in small-sample measurements and has a good performance. In addition, the article discusses some methods usually used under information scarcity, such as grey evaluating method, fuzzy evaluating method, maximum entropy method, and neural network method. Finally, the article provides a brief summary of various evaluating methods and believes that with the development of artificial intelligence technology, methods such as support vector machines and neural networks have broad prospects for application in complex measurement models and measurement environments.

Accurate Measurement of Limited Carbonyl Compounds and Heavy Metals Content in E-Liquid

WANG Xiangnan, ZHANG Airui, WANG Meiling, REN Danhua, ZHOU Yan, WANG Hai, CHENG Bin

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0247

Abstract(29)

HTML (17)

PDF(0)

Abstract:
Two analytical methods based on high performance liquid chromatography (HPLC) and hydride generation - atomic fluorescence spectroscopy (HG-AFS) were established to accurately determine four target carbonyl compounds (viz. formaldehyde, acetaldehyde, acrolein and 2,3-butadione) and two target heavy metals (via. arsenic and lead) in two different e-liquids, respectively. After their derivatization with 2,4-dinitrophenylhydrazine hydrochloride, the e-liquid specimens were analyzed quantitatively by HPLC. The results showed the detection limit of (0.53～1.2) μg/L, the measurement repeatability of 0.26%～2.2%, the spike recovery of 90%～103% and the combined uncertainty of 1.6%～4.5%. After their microwave digestion, the e-liquid specimens were analyzed quantitatively by HG-AFS. The results showed the detection limit of (0.007～0.025) ng/g, the measurement repeatability of 2.2%～4.5%, the spike recovery of 95%～101% and the combined uncertainty of 2.2%～4.9%. The two methods established have an advantage of simple sample pretreatment, high sensitivity, good repeatability and good accuracy, which are very suitable for the accurate determination of limited carbonyl compounds and heavy metals content in e-liquid and are also beneficial to the implementation of related national documented standards and the supervision of e-liquids.

Uncertainty Analysis of Wavelength Calibration of Monochromator Based on Neon Atomic Spectral Lamps

CHE Delu, ZHANG Jiawen, ZHANG Tingting, WANG Gao, LU Xiaofeng, WANG Bingying, ZHAO Yandong

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0239

Abstract(36)

HTML (19)

PDF(0)

Abstract:
As a kind of spectroscopic instrument, the monochromator is used to separate the mixed light into monochromatic light in the spectral responsivity of the photoelectric pyrometer. To improve the uncertainty level of temperature scale extension and reproduction for photoelectric pyrometers, it is necessary to calibrate the wavelength accuracy of the monochromator in the spectral responsivity for three commonly used photoelectric pyrometers with 660nm, 800nm and 900nm filters. In this paper, a neon atomic line lamp is used as a standard light source and a spectrum analyzer was used to scan the spectral line distribution in the range of 600nm～1200nm. The selected 37 characteristic spectral lines were then used to calibrate the wavelength error of the monochromator. The wavelength errors of the monochromator were analyzed in terms of slit width, wavelength correction method, detector response, nonlinearity, and calibration repeatability. The results showed that the uncertainty of the wavelength error was no more than 0.033 nm at 900nm wavelength. For the pyrometer with 660nm filter, the uncertainties of the temperature measurements at 1084.62°C and 3000°C were 0.01°C and 0.28°C, respectively.

Research on Rapid Analysis Methods for Benzene Series, Methane, and Total Hydrocarbons in Ambient Air

DENG Wenqing, DENG Fanfeng, ZHANG Ting, XU Bingyan, XIONG Huajing, PAN Yi

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0037

Abstract(24)

HTML (34)

PDF(5)

Abstract:
Fugitive emission of benzene series and total hydrocarbons has irreversible harm to the ecological environment and human health. The quick and accurate analysis of benzene series and total hydrocarbons has always been a research focus of ambient air monitoring. A quick method for the analysis of total hydrocarbons, methane, benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene and styrene was developed based on the multi-dimensional gas chromatograph with double FID detector. The results show that the target components can be analyzed accurately and quickly in 12 minutes by one injection, and the components show good linearity and repeatability over the measurement range. This method has excellent detection limit and the accuracy ranged from −7.7% to 0.2%. This method can be used for on-line calibration of analytical instruments in different spatiotemporal scenarios, and has potential application value in field navigation monitoring of ambient air.

Online First

DynamicMORE+

ScienceMORE+