计量科学与技术

Measurement Uncertainty Evaluation of a Leukemia Recognition Algorithm Based on Patient Clinical Data

JIANG Chaofan, YAN Jingting, WANG Tingting, ZHANG Jiatao, CUI Weiqun

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0125

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With the advent of the digital age, algorithms increasingly dominate the development of various industries and the emergence of new sectors, giving rise to a digital economy-led industrial landscape. Metrology, as the science of measurement and its application, is rapidly entering the digital era, with the promotion of digital transformation in the metrology industry becoming a top priority. Consequently, evaluating the accuracy and reliability of algorithmic software outputs has become a focal point of current research. This paper employs a digital metrology method based on reference data, using the output of a leukemia recognition algorithm software applied to patient clinical test data as the measurement result. It establishes an evaluation model for the leukemia recognition algorithm, outlines the specific process for assessing measurement uncertainty, and calculates the combined standard uncertainty of the measurand.

Uncertainty Evaluation of Piston Gauge Effective Area Using the Monte Carlo Method

WANG Bowen, YANG Yuanchao, YANG Ying, MA Kun, YUE Jin

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0013

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Uncertainty evaluation is a crucial component in the dissemination of measurement values. Following the publication of JJF 1059.2-2012 "Evaluation of Measurement Uncertainty Using the Monte Carlo Method," this approach has been increasingly applied across various metrological disciplines. Using Python, calculation codes were developed employing both the Monte Carlo method and the adaptive Monte Carlo method. Taking the calibration of a 100 MPa oil-medium piston gauge as an example, the uncertainty of the calibrated effective area was evaluated. The impact of uncertainties and probability distribution models of various input quantities on the output uncertainty was analyzed and compared with results from traditional evaluation methods. The findings indicate that the primary source of uncertainty in the calibration of the piston's effective area is the uncertainty introduced by the standard piston's effective area. Results obtained using the Monte Carlo method align with those from traditional evaluations, both yielding a relative expanded uncertainty (k=2) of 32 ppm. The probability density distribution of the calibrated effective area is determined by the probability density distribution of the main influencing factors.

Traceability Discussion on China VI Standard Automobile Exhaust Emission Detection

LIU Yiling, LI Xiuli, HAO Jingkun

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0058

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As the number of vehicles in China continues to increase, pollution from automobile exhaust has become increasingly severe. To control environmental pollution, China promulgated the "Air Pollution Prevention and Control Law of the People's Republic of China" as early as 1987. In 2013, the European Union released the Euro VI standard (EURO VI A-VI D). China, drawing on the Euro VI standard and considering its national conditions, issued GB 18352.6-2016 "Limits and Measurement Methods for Emissions from Light-Duty Vehicles (China 6)" (hereinafter referred to as the China VI standard) in 2016, which was implemented in phases starting from January 2020. This standard has set new requirements for the regulation and quality control traceability of automobile exhaust emissions. This article compares the differences in emission quality control requirements between the China V and China VI standards, and introduces the measurement methods for updated emission-limited pollutants in the China VI standard, including carbon monoxide (CO), nitrogen oxides (NOx), non-methane hydrocarbons (NMHC), nitrous oxide (N₂O), particle number (PN), and particulate matter (PM). It also describes China's exhaust emission detection and traceability technology from the aspects of developing national gas reference materials, establishing measurement standards, and founding national automobile testing centers. The analysis shows that existing capabilities and technical levels cannot meet some emission detection requirements in the China VI standard. The article proposes areas in current traceability technology that need further optimization, such as the condensation particle counter in particle number (PN) measurement instruments. It points out that research and improvement should be accelerated on metrological indicators like particle concentration attenuation coefficient, volatile particle removal efficiency, and dilution ratio. Regarding the requirements for determining methyl chloroformate and benzo[a]pyrene pollutants specified in the Euro VI standard, China currently lacks corresponding reference materials and traceability systems. It is necessary to develop compliant reference materials and establish traceability standards to prepare for increasingly updated quality control requirements both domestically and internationally. The article also offers suggestions in response to the proposed European seventh stage emission standard (Euro 7).

Research Progress on Cosmetic Matrix Reference Materials

LI Shuo, LIU Zhe, WU Xue, LI Qingwu, ZHANG Zhengdong, LI Li

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0159

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Over the past decade, cosmetic quality and safety issues have increasingly become a focus of consumer concern. Many well-known cosmetic brands have been reported to contain prohibited or restricted substances, not only harming consumer interests and causing economic losses to cosmetic companies but also challenging regulatory agencies and quality inspection institutions. Cosmetic matrix reference materials, due to their similarity to real samples, are widely used in developing and evaluating analytical methods for cosmetics with similar matrices, laboratory proficiency testing, and quality control of qualitative and quantitative analyses. They play an irreplaceable role in ensuring the accuracy, reliability, and traceability of test results, serving as important "measurement instruments" in the analytical field. This article reviews the development of cosmetic matrix reference materials in China from 1993 to the present. Starting from the definition and classification of cosmetics, it analyzes aspects such as the types of target additives, matrix types, and grading of reference materials. Based on the main challenges faced in this field, it anticipates the demand and trends for cosmetic matrix reference materials and proposes solutions to constraints on their development, aiming to provide references for future research on cosmetic matrix reference materials.

Analysis of the Equivalent Source Reflection Coefficient and Limitations of K. Shimaoka’s Measurement Method

JIA Chao, ZHANG Yihang, CHEN Shuo, LI Yong, CUI Xiaohai

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0090

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The equivalent source reflection coefficient plays a crucial role in microwave power measurement and uncertainty evaluation. This paper first discusses the relationship between the source reflection coefficient in amplitude-stabilized signal source systems and the equivalent source reflection coefficient when measuring power ratios using three-port devices. The concept of "equivalent" in the equivalent source reflection coefficient is explained from the perspective of the mismatch factor. Next, the working principle and limitations of K. Shimaoka's method for measuring equivalent source reflection coefficient using a network analyzer and three-port devices are briefly introduced. Finally, experiments and comparisons are conducted using N-type power dividers and directional couplers as measurement objects, based on K. Shimaoka's method and the traditional formula method in the 1-18 GHz frequency range. Results indicate that K. Shimaoka's method for measuring equivalent source reflection coefficient has certain limitations. Due to the small difference in transmission coefficients obtained in this calculation method, it is sensitive to minor changes and thus unsuitable for measuring equivalent source reflection coefficients when using three-port devices with good directionality (such as directional couplers).

Comparison of Direct Comparison Method in VNA and Power Transfer Standard Measurements

CAI Chengxin, ZHANG Yihang, YUAN Wenze, LI Yong, CUI Xiaohai

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0141

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The calibration factor is a parameter used to characterize the reading accuracy of RF power sensors, defined as the ratio of the power displayed by the sensor to the incident power. It is the object of power value transfer. This paper introduces the composition and measurement principles of the direct comparison method and the VNA-based direct comparison method. It describes the application of the equivalent source reflection coefficient in the direct calibration method. The calibration factor of the Rohde & Schwarz NRP50T power sensor was measured using both the direct calibration method and the VNA-based direct comparison method. Results show that the maximum difference between the corrected calibration factors measured by the two methods is 3.056%. The equivalent source reflection coefficient of the VNA-based direct comparison method is generally larger than that of the direct comparison method. The uncertainty evaluation method for the direct comparison method is well-established, making it currently the most prevalent RF power sensor calibration method.

Comparison of Calibration Methods in Free-Space Monostatic Reflection Coefficient Measurement

YANG Ruonan, LIANG Weijun, XU Hao

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0080

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Abstract:Microwave blackbodies provide high-precision brightness temperature signals for microwave radiometers to accurately calibrate observed target radiation signals. The emissivity of a microwave blackbody is a crucial parameter affecting its radiative characteristics. Therefore, accurately measuring blackbody emissivity is significant for enhancing radiometer calibration precision and ensuring measurement value traceability and effective transfer. Currently, blackbody emissivity is mainly obtained indirectly by measuring reflectivity. This study implements two calibration methods in free-space monostatic reflection coefficient measurement: the offset-short calibration method and the sliding-load calibration method. Time-domain gating techniques are utilized to address multipath reflection signals during small reflection measurements. A reflectivity measurement system was established, and the reflectivity of the same blackbody target was measured within the 75-110 GHz frequency band, with results analyzed and compared. The error terms solved by the two calibration methods exhibit high consistency, with measured emissivity reaching levels of 0.999-0.9999. When the measurement target satisfies approximation conditions, the sliding-load calibration method proves more efficient. Finally, using the offset-short method as an example, the Monte Carlo method was employed to evaluate the uncertainty of the solved blackbody target reflection coefficient.

Design of a Three-Axis Fiber Optic Gyro Combined Optical Path Detection System

SONG Liyuan, MI Qian

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0138

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This paper presents the design of a three-axis fiber optic gyro combined optical path detection system based on a Super Luminescent Diode (SLD) light source. The system employs synchronized temperature control and constant current drive circuits to ensure normal operation of the SLD across the full temperature range. The power supply section incorporates surge protection to effectively prevent transient impacts caused by switching power supplies or environmental changes, thus protecting the components. The detection system monitors the photodetector's output bias voltage under both light and no-light conditions, while simultaneously calculating the assembled optical path system loss through numerical analysis. This approach determines whether the fiber optic gyro's optical path technical specifications meet the design requirements. Finally, experimental validation demonstrates the effectiveness of the three-axis fiber optic gyro combined optical path detection system in batch production processes. The system improved the accuracy stability of fiber optic gyros to 87% and increased the finished product qualification rate to 96%.

Research on Calibration Method and Device for Ultrasonic String Phantoms Based on Intelligent Technology

QI Fang, WANG Tongyu, LIU Zhe, ZHU Weimin

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0350

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This study investigates the calibration method for ultrasonic Doppler string phantoms and presents the design and development of a calibration device based on intelligent technology. The device employs a dual-channel laser velocimeter to collect the rotational speeds of the drive and driven wheels of the ultrasonic string phantom. These data are then input into an analysis system to calculate the string velocity of the phantom. Additionally, the device can collect linear velocities at various points within the physiological waveform cycle and compare them with standard physiological waveform velocities in a database to determine whether the test waveform and physiological waveform curves meet requirements at the set velocity. Experimental results demonstrate that, compared to existing methods for detecting constant blood flow velocity, this method and device not only efficiently detect constant blood flow velocity but also intelligently assess physiological waveforms. This approach effectively addresses the calibration and traceability issues of ultrasonic string phantoms.

Gaussian Filtering Algorithm and LabVIEW Software Design for Non-Contact Measurement of Surface Roughness

CHEN Ting, WU Chunhui, LU Xin, WANG Yinghui, YE Huaichu, CHEN Ning, GUO Gangxiang

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0032

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This study investigates the adaptability of the Gaussian filtering method in non-contact measurement of surface roughness. Using surface profile data obtained from a spectral confocal displacement sensor as an example, the Gaussian filtering algorithm is introduced to compute the filtering centerline and separate the roughness signal. A program for the Gaussian filtering algorithm is designed on the LabVIEW platform, calculating the roughness values and comparing them with the results of current contact calibration. Experimental results indicate that the Maximum Permissible Error (MPE) of the Ra value after non-contact data processing is ±5%, demonstrating that the Gaussian filtering method is suitable for data processing in non-contact measurements. The modular design of the algorithm in LabVIEW is easy to implement, integrates well with other modules, is easy to maintain, and holds significant potential for wider application.

Low-Frequency Electric Field Standard Device Based on Parallel Plates

LIU Zhipeng, LIN Haoyu, WU Yanli, LI Enguang, ZHANG Bolin

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0086

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Due to the varying quality of probes produced by different manufacturers, the development of electric field standard devices has become particularly important. To meet the calibration requirements of low-frequency, high-field-strength electric field probes, a low-frequency electric field standard device was developed using the parallel plate method. The device consists of two square aluminum plates with a side length of 1 m and a plate spacing of 0.5 m. The frequency range is DC to 10 kHz, with an electric field strength range of 0 to 3000 V/m. Through theoretical analysis, software simulation, and experimental measurements, the effects of edge effects, plate material, structure shape, operating frequency, and other factors on the standard electric field generated by parallel plates were studied, and an uncertainty evaluation was conducted. A new measurement model was proposed, and uncertainty components caused by seven factors were evaluated separately: plate voltage, plate spacing, field uniformity within the parallel plates, probe fixture, probe alignment, finite size of parallel plates, and probe influence. The resulting expanded uncertainty is U=6.84% (k=2). The results show that the developed electric field standard device can meet the calibration requirements for low-frequency electric field probes.

Research on Valuation Method and Uncertainty Evaluation for Milk Somatic Cell Count Reference Materials

LIU Yingying, ZHOU Yuhu, WANG Ziquan

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0018

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A method based on microscopic imaging flow cytometry was established to measure the concentration of milk somatic cells in reference materials for milk somatic cell count. This method labels milk somatic cells using the fluorescent dye ethidium bromide. The single-cell multi-parameter microscopic images provided by microscopic imaging flow cytometry can effectively assist in identifying target cells in flow cytometric analysis, thereby improving the accuracy and repeatability of gating strategies. Through multiple measurements and analyses of milk somatic cell reference material samples with different somatic cell concentrations, it has been proven that this method has good intra-laboratory and inter-day repeatability. A mathematical model for measuring the concentration of milk somatic cells in reference materials for milk somatic cell count based on microscopic imaging flow cytometry was established. The analysis determined that the main sources of uncertainty in this measurement method come from measurement repeatability, sample pretreatment, reagent addition, gating operation, and instrument measurement volume deviation. Comprehensive evaluation targeting the candidate Grade V (～1.0×10⁶ cells/mL) reference material for milk somatic cell count prepared in this study shows that the relative uncertainty of the measurement method for milk somatic cell concentration based on microscopic imaging flow cytometry is 4.84%.

Discussion on Digital Metrology Method for Protocol-based On-board OBD Acquisition Terminal

ZHANG Hongbao, JIANG Kun, MA Ming, LU Jiawei, ZHENG Xiaoxiao

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0003

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To ensure the accuracy and reliability of on-board OBD (On-Board Diagnostics) acquisition terminals and improve the effectiveness of exhaust emission monitoring and overstandard screening for heavy-duty diesel vehicles, a digital metrology method is proposed. This paper introduces the definition, application, and current metrological status of on-board OBD acquisition terminals. It elaborates on the calibration method for these terminals and demonstrates their metrological characteristics from two aspects: determination of maximum permissible error and uncertainty evaluation. Three conclusions are drawn from the demonstration: the maximum permissible error of real-time engine data flow from the calibration device is set according to the data flow precision specified in the protocol, and the maximum tolerance of the on-board OBD acquisition terminal is set at twice the tolerance of the calibration device; the uncertainty introduced by the real-time engine data flow from the calibration device is $U_{\mathrm{rel}} =1 \times 10^{-6} $, $ k=\sqrt 3 $, and the uncertainty evaluation of the on-board OBD acquisition terminal meets the quantity transfer requirement of $U\le \mathrm{M}\mathrm{P}\mathrm{E}\mathrm{V}/3 $; test results show that the indication error of the on-board OBD acquisition terminal does not exceed the maximum permissible error, the metrological performance requirements are reasonable, and the calibration method is highly operable.

Rapid Analysis Method 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

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Fugitive emissions of benzene series compounds and total hydrocarbons pose irreversible harm to the ecological environment and human health. The rapid and accurate analysis of these compounds has long been a research focus in 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 using a multi-dimensional gas chromatograph with dual FID detectors. The results show that the target components can be accurately analyzed within 12 minutes with a single injection, and the components exhibit good linearity and repeatability across the measurement range. This method demonstrates excellent detection limits, with accuracy ranging from −7.7% to 0.2%. The method can be applied for on-line calibration of analytical instruments in various spatiotemporal scenarios, showing potential application value in field mobile monitoring of ambient air.

Study on the Impact of Multicollinearity Among Components on Near-Infrared Spectroscopy Quantitative Models

TIAN Lu, XU Dongqing, SU Wending, ZHANG Mengsha1, LI Yankun

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0014

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In quantitative analysis using near-infrared spectroscopy combined with chemometric methods, multicollinearity among variables is a key issue affecting the performance of spectral models. This study investigates the impact of multicollinearity between component concentrations on chemometric quantitative models. Two systems were designed with strong and weak correlations between the concentrations of vitamin B6 (low concentration) and vitamin B1 (high concentration), respectively. Using vitamin B6 as the target component, prediction models for component concentrations were established using near-infrared spectral information combined with partial least squares regression. The results show that when there are coexisting components with high concentrations strongly correlated to the target component in the system, the model can utilize information from these coexisting components to achieve more accurate predictions of the lower-concentration target component, thereby improving the precision of quantitative analysis for the target component. The application of this approach to the detection of commercially available oral solutions containing vitamins B6 and B1 further verified that strong multicollinearity between component concentrations can enhance the quantitative predictive ability of near-infrared spectral models. The conclusions of this study have significant theoretical and practical application value and can be applied to the simultaneous quantitative analysis of components in complex mixture systems.

Full Waveform Calibration Technique for Millimeter-Wave Wideband FMCW Signals

HE Zhao, XU Qinghua, LIU Xuefei, ZHANG Yichi

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0126

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To address the calibration needs of Frequency Modulated Continuous Wave (FMCW) signal testing equipment in millimeter-wave automotive radar applications and enhance measurement capabilities for complex analog-modulated signals in millimeter-wave broadband, we developed a hybrid measurement system. This system combines a frequency-domain full waveform metrology setup with FMCW testing equipment under calibration. By conducting in-situ, synchronous measurements of custom millimeter-wave FMCW signals, we achieved calibration and performance verification of commercial instruments. We thoroughly compared the performance of different measurement methods and equipment in the typical millimeter-wave radar frequency bands of 24 GHz and 60 GHz. Experimental results demonstrate that the frequency-domain full waveform metrology method outperforms relevant commercial instruments. The FMCW chirp deviation measurements under both 200 MHz narrowband and 2 GHz wideband conditions were an order of magnitude more precise, meeting the technical requirements for calibration and performance verification.

Nonuniform Frequency Sampling Technique for Near-Field Scattering Measurements

SI Weikang, WANG Weilong

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0066

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Traditional stepped frequency (SF) systems synthesize a large measurement bandwidth using a series of equidistant discrete frequency signals. However, due to sampling theorem limitations, time-domain signals corresponding to fixed frequency intervals exhibit periodicity. Consequently, background and multipath interference in the measurement environment may alias into the target area, adversely affecting imaging and scattering measurements. This paper explores rapid measurement methods for frequency-stepped systems and proposes a near-field scattering measurement technique based on nonuniform sampling. We analyze the impact of range ambiguity on scattering measurements and design optimization principles for the sampling function based on practical application requirements. The signal envelope is shaped using Poisson's formula and the principle of stationary phase (POSP). To address scattering image degradation caused by traditional nonuniform sampling reconstruction methods, we propose a weighted method compatible with the nonuniform sampling strategy. This method effectively suppresses aliasing interference, achieves high-resolution imaging, and improves the accuracy of near-field to far-field (NF-FF) transformations.

Study on Calibration Results of Thermistor-Type Power Sensors

NIE Lu, LI Xiangjun, CUI Xiaohai, WANG Zihao, ZHAO Yan

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0075

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Thermistor-type power meters use DC substitution to measure microwave and millimeter wave power. To compensate for environmental temperature changes, these power meters typically employ both measurement and compensation bridges, operating in a dual-bridge mode. When calibrating a coaxial thermistor-type power sensor using a microcalorimeter power standard, the measurement bridge alone cannot be used, even with stable environmental temperatures. To ensure valid calibration results, both environmental temperature compensation and ceramic core temperature variation compensation (due to dual-element errors) are necessary. Experiments show that at 18 GHz and 10 mW power level, the substituted power deviation for an N-type coaxial thermistor power sensor is 0.38% when measured with single versus dual-bridge power meters. For waveguide thermistor-type power sensors with single-element structures, calibrating effective efficiency does not require consideration of single versus dual-bridge measurement issues.

Experimental Study on the Influence of Input Power on Characteristic Parameters of Electromagnetic Reverberation Chambers

ZHANG Haomin, GUO Xiaotao, LIU Ke, LIU Tianxin

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0063

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Electromagnetic reverberation chambers are typically calibrated for characteristic parameters such as field uniformity and normalized field strength under low input power conditions. However, in practical applications like electromagnetic compatibility immunity testing, these chambers operate under high input power conditions. Currently, relevant international and domestic standards ignore this difference, providing no specific theoretical or experimental evidence. This paper presents a designed experimental study to investigate the influence of input power on the characteristic parameters of electromagnetic reverberation chambers. A rapid calibration technique using 3D photoelectric field probes was employed for low input power calibration, while high input power parameter measurements were conducted under conditions consistent with actual automotive component immunity tests. Results show that the impact of different input power levels on field uniformity is generally within ±0.5 dB, and the effect on normalized field strength is within 2 dB. Based on these findings, recommendations are provided for calibrating field uniformity and normalized field strength during electromagnetic reverberation chamber calibration and testing processes.

Long-Term Performance Analysis of Spectrum Analyzers Based on Metrological Scientific Data

ZHANG Yue, DING Sheng, LIN Tao, ZHAO Kejia, ZHANG Aimin

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0133

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Spectrum analyzers are key instruments widely used in radio electronics. The long-term stability of their critical parameters has been a significant concern for users and manufacturers. Accurate tracking of technical specifications plays a crucial role in the research, development, improvement, usage, and maintenance of these instruments. The National Institute of Metrology has accumulated calibration data for spectrum analyzers spanning over a decade. These metrological scientific data are characterized by traceability and accuracy. Based on these data, this paper introduces the operational principles, key performance specifications, and measurement calibration systems and methods of spectrum analyzers. It focuses on analyzing variations in the displayed average noise level and input frequency response during long-term usage of typical spectrum analyzers among representative domestic users. This study aims to provide a more reliable basis for the development, production, testing, and maintenance of spectrum analyzers.

Design and Implementation of Total Station Performance Evaluation and Early Warning System: Application of a Fuzzy Comprehensive Evaluation Method

SHI Lei, WANG Guanjun, LI Juan, YU Fang, JIN Hanle, LIU Lixia, TAN Yun, LI Qixiong, XIAO Yin

, Available online , doi: 10.12338/j.issn.2096-9015.2024.0111

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In the process of periodic verification of measuring instruments, a large number of verification data will be generated by measuring institutions, and the huge economic and social value is hidden. At present, it is still in the stage of analyzing and utilizing the quality or metrological performance of a single instrument. This paper puts forward a method of performance evaluation and failure early warning of measuring instruments according to the verification data of total station. Firstly, the verification data of total station are analyzed and processed, then the performance of total station measuring instruments is evaluated comprehensively by Topsis method, and then the product quality of total station manufacturers is evaluated by Vague set decision theory. Finally carry on the early warning analysis to the measuring instruments of the total station according to the limit difference and slope method, and finally build the performance evaluation and failure early warning system of the measuring instruments based on this method. Numerical experiments are carried out on the verification data of the total station, and the performance evaluation and failure early warning of the total station are effectively realized.

Determination and Uncertainty Assessment of Lactic Acid in Serum

ZHU Tianyi, DING Min, DUAN Manlei, MENG Jiaoran

, Available online , doi: 10.12338/j.issn.2096-9015.2023.0353

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An isotope dilution-gas chromatography-mass spectrometry method for the determination of lactic acid concentration in serum was established, and the uncertainty of the measurement results was evaluated. Sodium lactate isotope label was added to the serum sample as internal standard. After pretreatment and silanization derivatization, samples were detected by gas chromatography-tandem mass spectrometry in selected ion monitoring mode. The established quantitative analysis method was used to analyze five different concentrations of lactic acid in serum. The results showed that the method had good linearity, and the correlation coefficient was r>0.999. The average spike recovery rate was 101.2%～102.6%, and the relative standard deviation was 0.16%～0.59 % (n = 6). The concentration of lactic acid in five different serum was 1.16 mmol/L, 2.01 mmol/L, 5.50 mmol/L, 10.02 mmol/L, and 15.63 mmol/L, and the related expanded uncertainty U_rel of the results was less than 3.0% (k = 2). The method had good repeatability, high accuracy, reliable results, which could be used for accurate detection of lactic acid concentration in clinical serum sample.

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