Measurement最新文献

{"title":"Resolution of a positioning system with signal conditioning, based on a PSD optical sensor. Influence of system noise","authors":"José Luis Lázaro-Galilea,&nbsp;Álvaro De-La-Llana-Calvo,&nbsp;Carlos Andrés Luna-Vázquez,&nbsp;Rubén Gil-Vera,&nbsp;Marina Hernández-Grau","doi":"10.1016/j.measurement.2025.119137","DOIUrl":"10.1016/j.measurement.2025.119137","url":null,"abstract":"<div><div>This paper presents an analysis of the influence of electronic noise from sensors and electronic conditioning circuits on the resolution of measurement in a system based on a PSD (Position Sensitive Device) optical sensor. In a previous study, the authors proposed the design of signal conditioning circuits for optical sensors, which generally supply currents of tens of nA that must be suitably managed before the analogue-to-digital conversion process (total gain close to 20M). The present work comprises an analysis of resolution influenced by the noise of the proposed circuit, considering different choices for retrieving the desired information and taking into account the equivalent noise bandwidth (ENBW) used in each one. Shot noise, thermal noise and flicker noise have been considered for the different stages, as well as how next stages amplified noise of previous ones. Once the global expression of noise and its influence on resolution have been obtained, sensitivity from different parameters and the result of resolution were calculated and discussed. Some of the main results of this work indicate that the resolution on the sensor surface, depending on the method of information retrieval, is between 3 and <span><math><mrow><mn>12</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>. This value translated to resolution in space, at a distance of 3.5 m and with a lens on the sensor of focal f=8 mm is from 1.3 to 5.2 mm.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119137"},"PeriodicalIF":5.6,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modifying volumetric adsorption setup for combined measurement of adsorption heat and uptake","authors":"Mohd Abdullah Khan,&nbsp;Sourav Mitra","doi":"10.1016/j.measurement.2025.119138","DOIUrl":"10.1016/j.measurement.2025.119138","url":null,"abstract":"<div><div>This study presents a modification of a pre-existing volumetric adsorption setup to enable the determination of adsorption uptake and heat of adsorption (<em>Q_st</em>) simultaneously. The system integrates a thermopile-based heat flux sensor, vacuum-compatible electrical feedthroughs, and a high-resolution voltage acquisition. In-situ Joule-heating calibration yielded a heat flux sensor sensitivity of 15.23 ± 0.26 µV/(W/m²), overall calorimetric sensitivity of 11.74 ± 0.16 µV/mW and a resolution of 1.3 µW. The system is demonstrated using water vapour/MIL-101(Cr), with an optimal adsorbent mass of ∼0.75 g for reliable uptake and detectable heat signals. Directly measured <em>Q_st</em> ranged from 2965 to 2600 kJ/kg, capturing uptake-dependent variations and avoiding uncertainties associated with indirect estimation methods. Repeatability tests confirmed uptake and <em>Q_st</em> within ± 10 % across multiple runs. The proposed setup modification provides a practical and reliable approach for direct measurement of adsorption heat with minimal changes to existing volumetric setup at nominal additional cost of a standalone commercial calorimeter.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119138"},"PeriodicalIF":5.6,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving real-time precise point positioning ambiguity resolution by considering uncalibrated phase delay uncertainty","authors":"Xiaopeng Gong ,&nbsp;Liwenle Liu ,&nbsp;Rongxin Guo ,&nbsp;Guangyu Zhou ,&nbsp;Fu Zheng ,&nbsp;Shengfeng Gu","doi":"10.1016/j.measurement.2025.119165","DOIUrl":"10.1016/j.measurement.2025.119165","url":null,"abstract":"<div><div>Precise Point Positioning with Ambiguity Resolution (PPP-AR) is a crucial technology for real-time, centimeter-level positioning. However, when using the Least squares AMBiguity Decorrelation Adjustment (LAMBDA) method for integer ambiguity resolution, the uncertainty of Uncalibrated Phase Delay (UPD) correction is not considered at present. As a consequence, discrepancies arise between the ambiguity variance–covariance matrix of the PPP float solution and the precision of the real-valued ambiguities after UPD correction. To address this issue, we investigate the effect of incorporating UPD uncertainty into PPP-AR and implement an ambiguity-domain scheme that uses this uncertainty to assist integer ambiguity resolution. The satellite UPD residuals were used to represent the uncertainty of satellite UPD and improve the performance of PPP-AR. Experiments were conducted using data collected over a 14-day period from 122 reference stations distributed across China. The results demonstrate that accounting for UPD uncertainty can significantly enhance PPP-AR performance. In certain epochs, by incorporating UPD uncertainty, vertical positioning errors were reduced from over 15 cm to approximately 1 cm, while horizontal positioning errors decreased from decimeter-level to 1.2 cm. During ionospheric active periods, the new method also notably shortened the convergence time of PPP-AR. Under 0, 10, and 20 s delays in receiving real-time satellite orbit and clock offset products, the application of the UPD uncertainty reduced the convergence time in the vertical direction by 9.54 %, 10.97 %, and 13.58 %, respectively.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119165"},"PeriodicalIF":5.6,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating IoT-enabled automated impressed current cathodic protection systems with metal potential monitoring: a digital technology approach to address corrosion for promoting environmental ecosystem conservation","authors":"Faisal Budiman ,&nbsp;Dien Rahmawati ,&nbsp;Dana Aulia ,&nbsp;Vieri F. Sukma ,&nbsp;Teo Pao Ter ,&nbsp;Jafar A.I.S. Masood ,&nbsp;Reynard P.S. ,&nbsp;Agus Nurhidayat ,&nbsp;Daniel P.P. Mbarep ,&nbsp;Iman H.S. Sasto ,&nbsp;Ignasius D.A. Sutapa","doi":"10.1016/j.measurement.2025.119167","DOIUrl":"10.1016/j.measurement.2025.119167","url":null,"abstract":"<div><div>The study focuses on the development of an Internet of Things (IoT)-enabled automated Impressed Current Cathodic Protection (ICCP) device with metal potential monitoring features, aimed at addressing corrosion anticipation while protecting environmental ecosystems. By incorporating automation and IoT technology into the ICCP electrochemical setup, the built device not only serves functional corrosion immunity for metals but also enables real-time monitoring of their corrosion status through potential reading. Several corrosion experiments were conducted to investigate the built device’s effectiveness, with Zn and Fe metals as the objects to be protected under several corrosive conditions. The results indicated that the protected metal with ICCP always had lower potential readings compared to the non-protected metal. These potential trend values suggest the effective performance of ICCP, confirming the device’s potential capability to inhibit corrosion up to efficiency levels of 88% − 90% and 93% − 95% for Zn and Fe, respectively. Moreover, the device is also capable of sending data to a user interface mobile application using the Blynk IoT Platform over Wi-Fi communication, offering real-time data access and remote monitoring at anytime and anywhere. Thus, the integration of conventional ICCP systems with automation and IoT technology serves potential benefits to improve operational efficiency and effectiveness of corrosion protection. By implementing the corrosion protection technology, the device will act as the supporting system for environmental protection due to metal degradation, highlighting the importance of maintaining health as well as assuring natural resource protection and ecological stability in the environments.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119167"},"PeriodicalIF":5.6,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A random forest-optimized sensor fusion approach for non-invasive ammonia measurement: enhancing performance in jet impact-negative pressure reactors","authors":"Lingxing Hu,&nbsp;Yaohua Peng,&nbsp;Hongying Yan,&nbsp;Facheng Qiu,&nbsp;Zhiliang Cheng","doi":"10.1016/j.measurement.2025.119121","DOIUrl":"10.1016/j.measurement.2025.119121","url":null,"abstract":"<div><div>Ammonia removal in jet impact negative pressure reactors requires reliable monitoring without compromising vacuum conditions. This study developed a non-invasive detection system using an MQ135 sensor combined with spectral analysis and adaptive filtering to isolate 20–90 Hz vibrational noise characteristics. A machine learning framework integrating random forest-optimized fuzzy clustering was trained against infrared spectrophotometric reference data. Quantitative residual analysis demonstrated progressive error reduction during training, with measurement uncertainty converging to within a 5 % tolerance interval – significantly surpassing conventional methods. The optimized model achieved real-time ammonia concentration monitoring while maintaining negative pressure integrity, establishing a robust, non-invasive measurement methodology that significantly enhances measurement accuracy and reliability for gas concentration determination in harsh, confined environments under negative pressure.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119121"},"PeriodicalIF":5.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sound source localization of speed reducer with discontinuity of time–frequency energy distribution under non-stationary operating conditions","authors":"Yashan Li ,&nbsp;Xing Wu ,&nbsp;Xiaoqin Liu ,&nbsp;Wei Kang","doi":"10.1016/j.measurement.2025.119153","DOIUrl":"10.1016/j.measurement.2025.119153","url":null,"abstract":"<div><div>Speed reducer as a key transmission equipment, its operating state is related to the stability and reliability of the whole mechanical system. On industrial robots, the speed reducers often operate under the non-stationary conditions. The intensity and frequency components of the acoustic signals emitted by speed reducer change. Due to the complexity of the contacts inside the speed reducer and the uncertainty of the sound propagation path outside the reducer, the harmonic components in the acoustic signal are non-stationary and the energy is discontinuous. Therefore, a method combining time–frequency representation, Vold-Kalman filter and slice delay-and-sum beamforming is proposed to localize the sound source of reducers with time–frequency energy discontinuity under non-stationary operating conditions. Firstly, the parametric resampled time–frequency representations of each microphone signal are obtained and aggregated after standardization. Next, time–frequency ridges are extracted from the aggregated time–frequency representation and used as frequency vectors to reconstruct the time-domain signals of each microphone at different orders through the Vold-Kalman filter. Finally, the sound source localization maps of each order are calculated by the slice delay-and-sum beamforming method and all the order localization maps within the same slice are aggregated after standardization to improve localization accuracy. Standardization aggregation fuses the features of time–frequency representations of signals from different channels, improves the continuity of the time–frequency energy distribution, and provides a high-resolution time–frequency representation for accurate extraction of order signals. The effectiveness of the proposed method is verified by numerical simulations of non-stationary sound sources and localization experiment on industrial robot joint.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119153"},"PeriodicalIF":5.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An observation-domain fault detection and exclusion method considering measurement correlation for GNSS RTK in landslide monitoring","authors":"Ziwei Wang ,&nbsp;Guanwen Huang ,&nbsp;Adria Rovira Garcia ,&nbsp;Le Wang ,&nbsp;Qin Zhang ,&nbsp;Jian Wang","doi":"10.1016/j.measurement.2025.119144","DOIUrl":"10.1016/j.measurement.2025.119144","url":null,"abstract":"<div><div>With the global navigation satellite system (GNSS), especially the real-time kinematic (RTK) technology being widely used in landslide monitoring, the quality of GNSS satellite observations remains unstable in complex environments. The conventional fault detection and exclusion (FDE) method ignores the correlation among observations, and the RTK double differences (DD) model results in a high degree of correlation between test statistics. This may lead to contamination effects that adversely impact the accuracy of fault identification. This study proposes an adaptive FDE method that combines correlation coefficients weighted based on observation-domain correction (CWOD-FDE) for landslide monitoring. Unlike conventional satellite-by-satellite exclusion, our method classifies faults by observation type to preserve redundancy, introducing a maximum fault mode constraint and correlation-based weighting with observation coefficients to suppress contamination and improve detection reliability. Experimental results based on real landslide monitoring data indicate that the proposed CWOD-FDE method reduces the fault anomaly rate from approximately 50 % to 10 %, effectively minimizing false alarms and the erroneous exclusion of valid observations. The number of usable carrier-phase observations increased from 18 to 20, enhancing the redundancy of observation. In terms of positioning accuracy, the root mean square error (RMSE) in the East, North, and Up directions are 0.037 m, 0.031 m, and 0.058 m, respectively, representing improvements of 89.5 %, 91.3 %, and 92.4 % compared to extended Kalman Filter (EKF) positioning, and 74.5 %, 91.9 %, and 88.3 % compared to traditional FDE method. This study provides an effective FDE method within the observation domain for GNSS landslide monitoring.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119144"},"PeriodicalIF":5.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sub-pixel shift compensation method for temperature-induced drift in near-infrared optical positioning systems","authors":"Lingxiang Zheng ,&nbsp;Junyan Mei ,&nbsp;Rongqian Yang","doi":"10.1016/j.measurement.2025.119097","DOIUrl":"10.1016/j.measurement.2025.119097","url":null,"abstract":"<div><div>Near-infrared optical tracking systems (NIOTS), key components in surgical navigation, are widely used in various surgical procedures. However, thermal expansion within the system can cause sub-pixel shift errors, reducing positioning accuracy in 3D space. To explore these thermal effects and reduce temperature-related deviations, this study analyzes NIOTS parameters across varying temperatures and examines their relationship with thermal changes. A full-field data acquisition setup was developed, and a model was established to describe the link between temperature and sub-pixel shifts. Based on this model, a z axis correction was introduced to compensate for thermal-induced shifts. Experiments show that without compensation, the average measurement was 388.9465 mm, deviating -0.2245 mm from the true value. After compensation, the average improved to 389.1133 mm with a deviation of -0.0577 mm, achieving a 74% error reduction. Furthermore, the model maintained positioning errors within 0.1 mm in all directions during heating. These results confirm that the proposed compensation approach effectively mitigates temperature-induced drift and enhances NIOTS precision, providing a practical solution for stable and accurate surgical navigation.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119097"},"PeriodicalIF":5.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Integrating micro-hyperspectral imaging and machine learning to investigate mie scattering for early detection of microbial contamination in liquid fermentation cultures” [Measurement 257(Part A) (2026) 118620]","authors":"Libin Wu ,&nbsp;Shenghang Zhang ,&nbsp;Haiyong Weng ,&nbsp;Shangpeng Sun ,&nbsp;Dapeng Ye","doi":"10.1016/j.measurement.2025.119052","DOIUrl":"10.1016/j.measurement.2025.119052","url":null,"abstract":"","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"256 ","pages":"Article 119052"},"PeriodicalIF":5.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intelligence frameworks for environmental pollution assessment: a review on air and water quality monitoring systems","authors":"Alok Kumar Pati ,&nbsp;Alok Ranjan Tripathy ,&nbsp;Sonalika Subudhi","doi":"10.1016/j.measurement.2025.119122","DOIUrl":"10.1016/j.measurement.2025.119122","url":null,"abstract":"<div><div>Environmental pollution monitoring is essential to human health protection, biodiversity preservation, and ecological degradation minimization. Traditional methods of establishing air and water quality are scientifically valid but normally suffer from flaws such as excessive operational cost, low spatial-temporal resolution, slow processing, and low scalability. Advances in machine learning have introduced superior alternatives to escape these flaws. Particularly noteworthy are supervised learning paradigms such as random forests, support vector machines, and deep neural networks, which have demonstrated immense success in pollutant forecasting, anomaly detection, and low-cost sensor array calibration. Deep learning architectures, e.g., convolutional neural networks (CNNs) and recurrent neural networks (RNNs), have also enabled high-accuracy spatiotemporal estimation, with the capability to capture nuanced environmental dynamics at increased spatial and temporal resolutions. The integration of machine learning with IoT sensors and satellite remote sensing platforms has further facilitated the development of scalable, autonomous environmental intelligence systems for real-time, continuous monitoring across diverse landscapes. This study contributes by addressing critical gaps in current ML-based environmental monitoring systems, particularly sensor drift, data sparsity, and model generalizability. It proposes strategic directions such as explainable AI (XAI), multimodal data fusion, and domain adaptation to enhance system performance and applicability. The innovative potential of this study lies in not only advancing environmental monitoring capabilities but also in laying a roadmap for future intelligent stewardship systems that will be scalable, transparent, and effective post-2025. This article aims to create a general synthesis of current breakthroughs, highlight key limitations, and propose future research directions for the evolution of intelligent environmental monitoring systems.</div></div>","PeriodicalId":18349,"journal":{"name":"Measurement","volume":"258 ","pages":"Article 119122"},"PeriodicalIF":5.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}