MAPAN最新文献

{"title":"Dimensional Assessment and Measurement Uncertainty Estimation of H13 Tool Steel Specimen Fabricated using Metal Fused Filament Fabrication (M-FFF)","authors":"Vandana Jain,&nbsp;Harish Kumar,&nbsp;Girija Moona","doi":"10.1007/s12647-026-00918-1","DOIUrl":"10.1007/s12647-026-00918-1","url":null,"abstract":"<div><p>This work investigates the dimensional accuracy, shrinkage behavior, and dimensional measurement uncertainty of sintered H13 tool steel specimen manufactured through Metal Fused Filament Fabrication (M-FFF), implemented in this study through a Markforged Metal X (Atomic diffusion additive manufacturing based) system. Linear, circular, and angular dimensions were characterized through a high-accuracy Coordinate Measuring Machine (CMM), and uncertainty budgets were prepared in accordance with the Law of Propagation of Uncertainty (LPU) method. Results indicate anisotropic shrinkage with the X–Y plane undergoing more shrinkage (17.0–20.0%) than the Z-direction (15.0–15.5%), due to filament packing density, layer stacking limitations, and thermal gradients during debinding and sintering. Typical uncertainty evaluation for linear dimensions of the sintered samples demonstrated the maximum combined standard uncertainty of ± 14.008 µm, whereas the expanded uncertainty computed was ± 38.8 µm (at a coverage factor <i>k</i> = 2.77, corresponding to the confidence level of 95% for a Gaussian distribution). Angular dimensions showed the highest deviations up to 0.23° and, maximum combined uncertainty of ± 363 Arc seconds and the expanded uncertainty of ± 1006 Arc seconds (at a coverage factor <i>k</i> = 2.77, corresponding to the confidence level of 95% for a Gaussian distribution). The investigation points to the significant effect of anisotropic shrinkage on dimensional deviation and underpins the need for sound uncertainty quantification to separate the true process-induced deformation from measurement randomness. For high-precision applications such as molds and cutting tools, post-processing or enhanced process control is recommended to ensure compliance with dimensional and angular tolerance requirements.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 2","pages":"629 - 646"},"PeriodicalIF":1.3,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148060950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-Term Relationship of Atmospheric Trace Gases, Aerosols and Meteorology Over the Western Himalayan Region of India","authors":"Manisha,&nbsp;Ashish Ranjan,&nbsp;Shankar G. Aggarwal,&nbsp;Sachchidanand Singh,&nbsp;Sanjay K. Uniyal,&nbsp;Vijender Kumar Bambal,&nbsp;Sudhir Kumar Sharma","doi":"10.1007/s12647-026-00916-3","DOIUrl":"10.1007/s12647-026-00916-3","url":null,"abstract":"<div><p>Long-term monitoring (2015–2019) of atmospheric trace gases (NH₃, NO, NO₂ and SO₂) and aerosols (PM_2.5 and PM₁₀) was carried out at Palampur, Himachal Pradesh (HP) over the western Himalayan region of India to explore the influence of trace gases and meteorology on secondary inorganic aerosol (SIA) formation. During the entire monitoring period, the mean concentrations of NH₃, NO, NO₂ and SO₂ were 13.4 ± 8.9 µg m⁻³, 15.2 ± 12.6 µg m⁻³, 13.0 ± 9.8 µg m⁻³ and 7.1 ± 5.1 µg m⁻³, respectively, whereas the mean concentrations of PM_2.5 and PM₁₀ were 19.3 ± 14.5 µg m⁻³ and 39.4 ± 22.9 µg m⁻³, respectively. Although the annual mean concentrations of these trace gases and aerosols were well within the National Ambient Air Quality Standards (NAAQS) during 2015–2019, however, the daily mean value of these pollutants (NO, NO₂, SO₂, PM_2.5 and PM₁₀) occasionally breached the NAAQS (prescribed for the ecologically sensitive area as well as rural areas). The concentrations of trace gases and aerosols showed significant diurnal, seasonal and monthly variations during the monitoring period. The mean concentrations of all the trace gases were observed highest in winter (except SO₂) whereas the lowest in the monsoon season. The mass concentrations of PM_2.5 (23.1 ± 11.2 µg m⁻³) and PM₁₀ (47.5 ± 13.3 µg m⁻³) were recorded highest in summer and lowest in monsoon seasons. The mean PM_2.5/PM₁₀ ratio during winter, summer and post-monsoon seasons were estimated to be 0.52, 0.49, and 0.52, respectively; indicating almost 50% contribution of fine fraction of aerosol in PM₁₀ (except monsoon season) supporting the influence of secondary formation. The SIA formation through gas-to-particle process over the study site may leads the dense haze formation during winter and colder months. Result reveals the inter-annual variability of trace gases (NH₃, NO, NO₂ and SO₂) and aerosols (PM_2.5 and PM₁₀) concentrations over the monitoring site in the western Himalayas. The surface wind analysis with wind direction revealed the local activities/tourism, agricultural activities, vehicular emissions and combustion to be the main sources of trace gases and aerosols over the western Himalayas. The linear positive relationship of NH₃ with NO, SO₂, and PM_2.5 suggests the influence of trace gases in the SIA formation at the study site. The present study on the interaction of ambient trace gases and aerosols over the Himalayas region is a valuable document for the policymakers for further mitigation and reduction in pollutants loading to improve the air quality of the Himalayan region.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 2","pages":"751 - 763"},"PeriodicalIF":1.3,"publicationDate":"2026-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148060882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Stacked GRU Approach to Enhance Predictive Accuracy of Global Horizontal Irradiance","authors":"Girijapati Sharma,&nbsp;Subhash Chandra,&nbsp;Arvind Kumar Yadav","doi":"10.1007/s12647-026-00897-3","DOIUrl":"10.1007/s12647-026-00897-3","url":null,"abstract":"<div><p>The recent outbreaks solar energy generation, some challenges have popped up owing to solar intermittent behaviour, require an accurate estimation of the worldwide solar radiation. In this reference AI-ML algorithms are gaining popularity and effectiveness in calculating solar radiation. Since collinearity might cause troubles such as unstable parameter estimation, inaccurate models, and poor predictive performance. However, multiple linearity tends to become a major issue in linear models. To address these issues, the spearman rank Correlation (SRC) and variance inflation factor (VIF) was introduced, and a new variable selection method called Spearman Rank Correlation-Variance Inflation Factor (SRC-VIF) was proposed, in addition to this article presents a better stack ensemble with GRU (SE-GRU) regressor include the machine learning models like, Random Forest Regressor (RF), Support Vector Regressor (SVR), Multilayer perceptron Regressor (MLP), K-Nearest Neighbor Regressor <b>(</b>KNN), Light Gradient Boost Machine (LGMs), CatBoost Regressor (CB), and Extreme Gradient Boost (XGBost), while the ensemble stacking with GRU regressor is used as meta learners. The ensemble technique includes stacking, blending, bagging and boosting methodology. In this paper use above all technique for the prediction of solar radiation of Agra (India) location. With the help of this technique we precise the result and able to minimise the errors in predicted value such as Mean Absolute Error (MAE) 15–56%, Root Mean Squared error (RMSE) 22–60% and R squared error (R2) 26–45%. Ultimately, we can say that the ensemble technique helps to decrease prediction errors and improves planning for intermittent solar resources.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 1","pages":"253 - 283"},"PeriodicalIF":1.3,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and Experimental Validation of a Dual-Position East–West North-Seeking Downhole Multi-Parameter Tool Using a Hybrid MEMS-IMU and Single-Axis Fiber-Optic Gyroscope","authors":"Liangzhu Yan,&nbsp;Yahang Zhou,&nbsp;Youyan Jian,&nbsp;Zhiyuan Zhou,&nbsp;Qiao Liu","doi":"10.1007/s12647-026-00905-6","DOIUrl":"10.1007/s12647-026-00905-6","url":null,"abstract":"<div><p>This paper presents a downhole instrument that leverages a dual-position north-seeking technique to achieve high-precision six-degree-of-freedom (6-DoF) navigation in borehole environments where external positioning signals are unavailable. The instrument integrates a MEMS-based inertial measurement unit (IMU) with a single-axis optical gyroscope, together with multiple environmental sensors, forming a compact multi-parameter measurement tool. Through a two-orientation azimuth determination method, the system mitigates gyroscope bias and resolves heading ambiguity. We reformulate the theoretical basis of this dual-position gyrocompassing approach and embed it within the instrument’s sensor-fusion architecture to continuously estimate borehole attitude—inclination, azimuth, and toolface—together with incremental displacement in real time. Analytical modeling, simulation, and laboratory experiments confirm robust and accurate north-seeking performance: after calibration, azimuth errors are typically.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 2","pages":"613 - 628"},"PeriodicalIF":1.3,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148061086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PM1 in the Atmosphere: Mapping Global Trends, Characterization, Source Attribution, and Health Consequences","authors":"Suryakant Manikpuri,&nbsp;Manas Kanti Deb,&nbsp;Shamsh Pervez,&nbsp;Shubhra Sinha,&nbsp;Rajiv Nayan,&nbsp;Indrapal Karbhal","doi":"10.1007/s12647-026-00900-x","DOIUrl":"10.1007/s12647-026-00900-x","url":null,"abstract":"<div><p>This systematic review integrates data from 56 studies from the period 2000–2024 to analyze the concentration, sources, and health effects of ambient PM₁ in India and other parts of the world. The mean concentration of PM₁, as determined using filter-based methodologies in different areas of India, was 102.84 ± 51.63 μg m⁻³, varying between 30.03 and 231 μg m⁻³. In studies that addressed source apportionment in 14 Asian region, secondary aerosol formation was identified as the primary contributor of PM₁, followed by industrial emissions and biomass burning. The review additionally addresses the analytical and sampling methods employed, for mass measurements of PM₁ as well as the chemical profiling. Notably, a clear gap exists regarding direct, on-site monitoring efforts to develop accurate chemical source profiles for PM₁. Many studies lack thorough chemical characterization, especially concerning carbonaceous matter, ions, and elements, which are crucial for precise source identification. Additionally, research on the long-term atmospheric and health effects of PM₁ exposure remains limited, with chronic health impacts receiving insufficient attention. These gaps highlight the urgent need for more comprehensive and targeted research to advance understanding of PM₁ pollution and its broader environmental and public health implications.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 1","pages":"361 - 396"},"PeriodicalIF":1.3,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metrological Foundations for Soil Analysis: A Global Review of Certified Reference Materials for Agricultural Laboratories","authors":"Aziz Soulaimani,&nbsp;Reda Oulfakir,&nbsp;Latifa Hajji,&nbsp;Said Gmouh","doi":"10.1007/s12647-026-00894-6","DOIUrl":"10.1007/s12647-026-00894-6","url":null,"abstract":"<div><p>Certified Reference Materials (CRMs) constitute the metrological foundation for reliable and comparable soil measurements in agricultural laboratories worldwide. They provide SI-traceable benchmarks for instrument calibration, method validation, and quality control in the determination of key agronomic parameters, including texture, pH, electrical conductivity, organic carbon, macro- and micronutrients, and potentially toxic elements.</p><p>This review critically examines the international metrological framework governing soil CRMs, with emphasis on ISO/IEC 17025, ISO 17034, and the emerging ISO 33400 series (notably ISO 33405 and ISO 33401), which collectively define requirements for sampling, pretreatment, homogenization, homogeneity and stability assessment, characterization, value assignment, and uncertainty evaluation. It summarises global advances in CRM production and evaluates the current availability of soil matrix CRMs from major producers such as NIST, BAM, LGC, and the JRC.</p><p>Despite a growing market, the portfolio of soil CRMs remains limited relative to the diversity of pedological and agro-climatic conditions. High acquisition costs, logistical constraints, and limited regional production capacity particularly constrain laboratories in emerging economies, hindering method validation, proficiency testing, accreditation, and interlaboratory comparability.</p><p>The review identifies critical gaps in matrix-specific soil CRMs that should be addressed as a priority and outlines the investment, infrastructure development, and international collaboration required to strengthen regional production capabilities and metrological traceability chains. Addressing these gaps is essential to enhance measurement confidence, support ISO/IEC 17025 accreditation, and underpin evidence-based agricultural management, food security, and environmental regulation.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 1","pages":"341 - 359"},"PeriodicalIF":1.3,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Novel Technique to Enhance the Magnitude of NavIC–IR signal at Higher Elevation Angles for the Evaluation of Volumetric Soil Moisture","authors":"C. D. Raisy,&nbsp;Sharda Vashisth,&nbsp;Amitava Sen Gupta","doi":"10.1007/s12647-026-00914-5","DOIUrl":"10.1007/s12647-026-00914-5","url":null,"abstract":"<div><p>Signals in the L band frequency range exhibit a strong sensitivity to variations in soil moisture. The Indian Regional Navigation Satellite System, known as NavIC, utilizes the L5 spectrum for both transmission and reception. These L5 signals can serve as signals of opportunity for remotely estimating soil moisture. This paper utilizes the NavIC-IR approach to assess soil moisture. To enhance the peak-to-peak amplitude of the interference pattern generated by direct and reflected signals, the antenna is horizontally oriented. This orientation ensures that both the direct and reflected signals are received through the front lobe of the antenna, which has high gain and is designed to receive right-hand circularly polarized (RHCP) signals. Due to its specific design for receiving RHCP transmissions, the antenna is unable to pick up the reflected left-hand circularly polarized (LHCP) signal. As a result, the phase shift in the received reflected signal induced by soil moisture variation is only due to the RHCP reflected signal. The experiment demonstrates a linear relationship between the phase of the reflected signal and volumetric soil moisture. A 2° change in the reflected signal phase corresponds to a 10% change in volumetric soil moisture. Furthermore, the peak-to-peak amplitude of the interference pattern nearly doubled.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 2","pages":"601 - 611"},"PeriodicalIF":1.3,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148061031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal Assessment of Aerosol Optical Depth and Climatic Interactions Over Jaipur City: Trends, Anomalies, and Urban Air Quality Insights","authors":"Aman Yadav,&nbsp;A. S. Jethoo,&nbsp;Kaushlandra Bairwa","doi":"10.1007/s12647-026-00915-4","DOIUrl":"10.1007/s12647-026-00915-4","url":null,"abstract":"<div><p>Understanding aerosols' behaviour over semi-arid urban regions is critical for assessing air quality and its climatic implications. This study investigates the spatiotemporal alteration of Aerosol Optical Depth (AOD) over Jaipur, India, using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data at 0.47 µm and 0.55 µm wavelengths, and 0.50 µm from the ground-based AErosol RObotic NETwork (AERONET) site for 2018 to 2024. The objective is to analyse seasonal patterns, detect long-term trends, and assess the relationships between various wavelengths of AOD and Particulate Matter (PM₁₀ &amp; PM_2.5) collected from ground-based stations. Monthly AOD showed consistent seasonal peaks during the pre-monsoon months, with maximum values in May 2023 and the lowest concentrations during the monsoon due to effective wet deposition. Linear regression analysis across AOD wavelengths showed weak declining trends, with statistical significance observed only at 0.50 µm (slope ≈ − 0.002 per month, <i>p</i> &lt; 0.05) and <i>R</i>² values below 0.06, confirming a poor linear fit and highlighting episodic variability. Pearson correlation analysis revealed a high degree of association between AOD values at 0.47 μm and 0.55 μm wavelengths, indicating consistency in aerosol spectral behaviour across these channels. Robust anomaly analysis (|<i>Z</i>|≥ 2.5) identifies recurrent extreme aerosol loading events, particularly during pre-monsoon, winter, and post-monsoon periods, underscoring the role of short-term processes in shaping AOD variability. These correspond to episodic aerosol events such as regional dust transport, biomass burning, or festival-related emissions. These findings emphasise the importance of high-frequency monitoring and event-based analysis to support urban air quality regulation and climate resilience planning in regions like Jaipur.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 2","pages":"589 - 600"},"PeriodicalIF":1.3,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148060691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Verification of Calibration Results of Anemometer Calibration Devices by Two Methods and Their Performance Evaluation","authors":"Yan Qi,&nbsp;Mingming Wei,&nbsp;Shurui Peng,&nbsp;Taocheng Zhou","doi":"10.1007/s12647-026-00913-6","DOIUrl":"10.1007/s12647-026-00913-6","url":null,"abstract":"<div><p>Research on wind speed measurement accuracy is of great significance for meteorological disaster prevention and reduction and wind power generation. Anemometer calibration devices (ACD) play a crucial role in ensuring the accurate transmission of wind speed values. To guarantee the stable performance and reliable transmission of the ACD. In practical applications, accurate wind speed measurement is essential for meteorological departments to issue accurate weather forecasts and early warnings, reducing the losses caused by meteorological disasters. This study conducted a verification research on the calibration results of ACD. Firstly, the working principle and calibration method of the assessed ACD are introduced. Then, the Guide to the Expression of Uncertainty in Measurement (GUM) is used to evaluate the measurement uncertainty. A wind speed sensor and a portable three-cup anemometer are selected and calibrated with the device to obtain calibration results. Finally, these calibrated objects are sent to different calibration institutions for recalibration, and both transfer comparison method and comparison method are employed to verify the calibration results. The key conclusions are as follows: The wind speed sensor is more stable than the portable three—cup anemometer. When using the transfer comparison method, all measured anemometers passed validation. However, when using the comparison method, the portable three—cup anemometer failed to meet verification standards at some wind speed points due to its own poor stability rather than inaccurate ACD calibration. The transfer comparison method has traceability, accuracy, and reliability. The studied ACD studied has stable performance and reliable transmission capabilities, making it suitable for calibrating working—level anemometers. When verifying the calibration results of ACD, it is recommended to choose a stable device under test (DUT) such as a wind speed sensor, to ensure the authenticity and reliability of the results.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 2","pages":"575 - 588"},"PeriodicalIF":1.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148060855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance Evaluation of a Digital Density Meter Method for High-Precision Hydrometer Calibration","authors":"Mohamed Hamdy,&nbsp;Alaaeldin A. Eltawil,&nbsp;B. M. Sayed","doi":"10.1007/s12647-026-00893-7","DOIUrl":"10.1007/s12647-026-00893-7","url":null,"abstract":"<div><p>Accurate calibration of density hydrometers is critical for many applications. This study evaluates an alternative calibration method using a Digital Density Meter (DDM) and compares its performance against the established hydrostatic weighing technique (Cuckow's method). Full description of the proceeding methods is described. Experiments were conducted using three reference liquids at controlled temperatures (20 °C, 23 °C, and 25 °C) to calibrate different ranges of hydrometers: three with high resolution (0.0001 g/cm³) and three with lower resolution (0.001 g/cm³). The influence of the DDM's precision was also analyzed. According to the calibration results, the errors obtained using the DDM method and the hydrostatic weighing technique range from 31 to 95 ppm. The expanded uncertainty of the DDM method is approximately twice that of the hydrostatic weighing technique. Three statistical methods are used to evaluate the performance for each method (weighted mean reference value and Chi-squared consistency test and degree of equivalence test. For the high-resolution hydrometers, calibration compared with a 6-digit DDM yielded a standard uncertainty of approximately 122 ppm. This uncertainty is projected to increase only slightly to 126 ppm and 205 ppm for 5-digit and 4-digit DDMs, respectively. For the lower-resolution hydrometers (3-digit), the hydrometer's resolution became the dominant source of uncertainty, resulting in a standard uncertainty of approximately 353 ppm, with negligible impact from the DDM's precision. The results validate the DDM-based method as a robust alternative to hydrostatic weighing and provide a clear framework for estimating the achievable uncertainty for hydrometers of different resolutions.</p></div>","PeriodicalId":689,"journal":{"name":"MAPAN","volume":"41 1","pages":"313 - 325"},"PeriodicalIF":1.3,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}