Evaluation Of Measurement Uncertainty Research Articles

Test of conformance or non-conformance with geometrical specifications

Abstract Systematic and random measurement errors are the cause of uncertain conformance and non-conformance statements. A wrong conformance statement occurs if the workpiece is accepted and is a reject part (type II error or false-negative) and a wrong non-conformance statement if the workpiece is rejected and is an in-spec part (type I error or false-positive). In order to avoid type I and type II errors, measurement uncertainty must be taken into account in the conformance and non-conformance testing. In practice, some procedures are used to consider measurement errors or the uncertainty that deviate from the state-of-the-art in research and technology. As these methods have become established over many years, they are still widely used despite better theoretical knowledge. The standard ISO 14253-1:2017 specifies a procedure based on probability and measurement uncertainty that is in accordance to the internationally accepted “Guide to the expression of uncertainty in measurement” and its supplements but is often not used due to the complexity of the evaluation of measurement uncertainty. In this contribution we give an overview and comparison of the different existing methods and provide an suggestion for supplementing the standard ISO 14253-1:2017, as Monte Carlo simulations enable a direct probability-based conformance and non-conformance testing even for complex measurement processes.

New guidelines on radiation survey and sanitary assessment of residential, public and industrial buildings and facilities in terms of radiation safety indicators. Part 1

The paper (in two parts) presents an overview of the new guidelines MR 2.6.1.0333-23 (approved on 01 December 2023) that supersede guidelines MU 2.6.1.2838-11, which were used for organizing radiation surveys of residential, public and industrial buildings and facilities and their sanitary assessment in terms of radiation safety indicators over the past 12 years. Due to a large number of critical comments on the document received during this period, a need for significant revision emerged. The scope of the revised document was expanded and now covers all stages of the life cycle of buildings and facilities: commissioning; operation period; overhaul and reconstruction; demolition. In the first part of the paper, the structure and legal status of the new guidelines are considered, as well as the main innovations in terms of measuring the ambient dose equivalent rate of gamma radiation, searching and identifying local radiation anomalies and sites of radioactive contamination, measuring surface contamination levels, and determining the minimum number of premises to be surveyed. The reasons for the introduction of certain changes are outlined. The issues of evaluation of measurement uncertainty, reporting of measurement results and registration of test reports are covered in detail. In the second part of the paper, numerous innovations will be considered in terms of estimating the indoor average annual equilibrium equivalent concentration of radon isotopes.

Measurement uncertainty evaluation in soil liquid limit testing

Measurement uncertainty evaluation in soil liquid limit testing

Small sample uncertainty evaluation of industrial robot position accuracy measurement based on grey model

The measurement of position accuracy of industrial robots has high complexity, and its uncertainty assessment is one of the important research topics. This study analyses the principle of measuring the position accuracy of industrial robots by laser tracker, the evaluation model of the measurement uncertainty of the position accuracy of industrial robots is established, and various factors affecting the measurement results are analysed, including industrial robot itself, the measurement instrument, the measurement personnel, the measurement strategy and the data processing method. There is a very small sample problem in the uncertainty evaluation process of the position accuracy of industrial robots. The literature and experiments show that the reliability of The Guide to the Expression of Uncertainty in Measurement is low under the condition of very small sample. In this study, an improved grey method is proposed to evaluate the uncertainty. The principle of the improved grey method is discussed in detail, and the general steps of the improved grey method are summarized. The experimental data prove that the standard deviation of very small sample calculated by the improved grey method has higher accuracy. Taking the position accuracy of an industrial robot measured by a laser tracker as an example, the improved grey method is successfully applied to the measurement uncertainty evaluation of the position accuracy of industrial robots.

Evaluation of measurement uncertainty for 19 clinical chemistry analytes and comparison with analytical performance specifications

Evaluation of measurement uncertainty for 19 clinical chemistry analytes and comparison with analytical performance specifications

Uncertainty evaluation for wind speed measurement part (1): “GUM method and Monte Carlo method”

Due to the lack of analysis and research on the performance of different uncertainty evaluation methods in the field of wind speed measurement, it is difficult to choose the most favorable uncertainty evaluation method in the specific wind speed measurement, which will affect the efficiency and accuracy of results. In view of the above situation, this study applied three commonly used uncertainty evaluation methods (conventional GUM method, correlation GUM method and MCM method) to the uncertainty evaluation of wind speed measurement, and analyzed the performance of different methods to provide technical support for specific applications. Firstly, taking the pitot tube wind speed measurement system as an example, the principle and model of wind speed measurement are introduced; Secondly, explain the steps and processes of the above three methods for evaluating uncertainty; Finally, taking a 10 m/s wind speed measurement as an example, the above three methods were used (The correlation GUM method incorporates the correlation between wind tunnel stability and uniformity in its evaluation) to evaluate the uncertainty of wind speed measurement in the Pitot tube wind speed measurement system, and the evaluation results were verified and compared accordingly. The following results were obtained:1) The three uncertainty evaluation methods are all applicable to the evaluation of wind speed measurement uncertainty in this field; 2) The accuracy of evaluation results: MCM method > correlation GUM > conventional GUM, among which correlation GUM method effectively improves the accuracy of uncertainty U95 by 23 % compared to conventional GUM method; 3) Evaluation method operability: MCM method > conventional GUM > correlated GUM. Therefore, we suggest that, when evaluating the uncertainty of wind speed measurement, the MCM method should be given priority when there are high requirements for accuracy and operability. When there are difficulties in the use and promotion of MCM, but there is a high requirement for accuracy, the correlation GUM method can be used. When the accuracy requirement is not high and the calculation is not too complicated, the conventional GUM method can be used.

Validation, measurement uncertainty estimation and evaluation of UHPLC greenness for simultaneous determination of metoprolol tartrate and hydrochlorothiazide in binary tablet

A novel green ultra high performance liquid chromatography (UHPLC) method was validated and estimated the measurement uncertainty for simultaneous determination of metoprolol tartrate (MET) and hydrochlorothiazide (HCT) in binary tablet. A Zorbax® SB-C18 column with isocratic elution (flow rate 0.9 mL min−1) at 25°C was used. Analytes and HCT degradation product were separated in approximately 1 min using acetonitrile:water:triethylamine (17:83:0.2, v/v) as mobile phase. Analytical curves were linear with (R 2 > 0.99 for MET and HCT) with detection limits of 2.42 and 1.05 µg mL−1 for MET and HCT, respectively. Precision measurements showed RSD% from 0.39 to 1.2% and method accuracy by recovery tests was 100 ± 2%. Measurement uncertainties using Eurachem procedure were 100.1 ± 2.8% and 100.3 ± 2.4% for MET and HCT, respectively. This UHPLC method was accurate, precise, linear and selective, making it suitable for pharmaceutical quality control. It also proved eco-friendly compared to other reported methods.

Evaluation of measurement uncertainty of drop hammer impact test for composite materials

Future aircraft structures are usually dominated by composites, and one of the key defects and forms of damage to composite structures is the impact damage caused by low-energy (especially low-speed) foreign matter. This kind of low-energy impact test is usually completed by the drop hammer testing machine, so accurately assessing the impact test of the falling hammer completed in accordance with the standard test method, and the reliability of the permissible value of the impact performance of the objective reaction composite is of great significance to the future aircraft structure design. Taking a standard composite test piece as an example, considering the key factors in the whole process of impact test, a mathematical model is constructed, and the measurement uncertainty of different configuration composite test pieces of different configurations is calculated according to the test data, which provides a basis for aircraft structural design.

Reference materials: A review

Several factors have increased the use of reference materials in laboratories. This can be explained by the fact that the reference materials have several roles, namely: the confirmation of the identity of unknown materials and/or the determination of their properties; the calibration of measuring equipment; the validation of methods; the realization of proficiency tests; etc. To be able to produce and use them, a set of standards and guidelines concerning the subject of reference materials has been established. There are several producers of reference materials in many fields, but finding the right choice is sometimes considered difficult given the multitude of materials to be analyzed that do not correspond perfectly to the reference material, especially in the case of matrices. This makes the market always seek new materials. To develop them, five steps are essential: material preparation, homogeneity study, stability study, characterization, and evaluation of measurement uncertainties. These steps are equally important; the fact of highlighting less than one of them will imply a significant decrease in the quality of the reference material developed. This review seeks to furnish the scientific community with a paper elucidating the functions of these materials in research laboratories, the normative references devised to standardize their production and utilization, the factors influencing their production, and the essential steps for their development.

Mathematical modeling applied to the uncertainty analysis of a tank prover calibration: Understanding the influence of calibration conditions on the GUM validation using the Monte Carlo method

This paper presents the calibration of the volume of a tank prover using the gravimetric method. A mathematical model of this calibration has been developed and it is non-linear. An evaluation of measurement uncertainty of the tank prover calibration has been carried out using the “Guide to the Expression of Uncertainty in Measurement” (GUM) and the Monte Carlo method. The measurement results have been compared. The influence of calibration conditions on the validation of GUM method by means of the Monte Carlo method (MCM) has been investigated computationally, as well as the behavior of the expanded uncertainty (GUM method) as a function of these calibration conditions. Seven case studies have been analyzed in this research work. In reference case, the tank prover calibration is carried out in the normal laboratory condition. In other case studies, the tank prover calibration is modeled in various hypothetical situations, such as change in tank prover scale quality, variation of calibration water density during calibration, large temperature gradient of water inside the tank prover and combination of the above conditions. In general, GUM method has not been validated by MCM due to one or more of the following conditions: a) the dominant source of uncertainty is a rectangular distribution; b) the uncertainty budget contains large uncertainty and the measurand model is non-linear; c) the measurand probability distribution is not normal.

Experimental Uncertainty Evaluation in Optical Measurements of Micro-Injection Molded Products

Optical measurements are increasingly widely used as preferential techniques to evaluate dimensional and surface quantities in micro-products. However, uncertainty estimation is more critical on micro-products than macro, and it needs careful attention for evaluating the obtained quality, the requested tolerance, and the correct setting of experimental process settings. In this study, optical measurements characterized micro-injected products by linear and surface acquisition and considered all the sources contributing to uncertainties. The results show that the measure uncertainty could be underestimated if only the standard deviation on simple measurements is considered; this could cause a significant restriction of the estimated range covering the measured values. Furthermore, the findings confirm that the correct evaluation of the potential uncertainties contributes to accurately assessing the process behavior and improving product quality.

Uncertainty evaluation of non-invasive multi-parameter detector measurements in quality assurance of diagnostic radiology.

To optimize the patient dose and image quality through quality assurance (QA) of diagnostic x-ray equipment and to ensure compliance with international and national standards in x-ray specification parameters, the use of contactless and quick non-invasive instruments has gained importance. Considering the importance of equipment qualification and the intervention level for equipment management, it is vital to account for uncertainties in the measurement of parameters in diagnostic radiology. However, the limits and measurement uncertainties associated with the parameter measurement are not well established and many technical and scientific literature provide different tolerance values, either as absolute or in terms of percentage. In this paper, the authors analyze non-invasive multi-parameter detector measurements with the aim to (i) improve the accuracy in measurement of x-ray parameters (kilovoltage, dose, and exposure time); (ii) estimate the uncertainty associated with such measurements; (iii) analyze the tolerance values prescribed by various professional and regulatory bodies and propose an improvised method of reporting the parameters. The approach adopted in this paper takes into account the uncertainties associated with traditional instruments and the subjectivity in the measurements. Estimated uncertainty for kV measurements in the range between 1.45 kV at 40 kV measurements and 4.88 kV at 150 kV measurements. The MU associated with the dose measurement is estimated to be 6.2% at 110 kVp, 100 mA, and 500 msec. Maximum MU estimated at 10 msec exposure time is 4.5% and with MU of 5% deviation added to 9.5%. The current practice of reporting the measured mean values deviation without considering the inherent measurement uncertainty may not be a correct quantification procedure in QA. This is evident from the case study that 3% addition to the measured kV, 6.2% addition in the measured dose, and 4.5% to the measured time accounts for measurement uncertainty.

A brief guide to measurement uncertainty (IUPAC Technical Report)

Abstract This Brief Guide reintroduces readers to the main concepts and technical tools used for the evaluation and expression of measurement uncertainty, including both classical and Bayesian statistical methods. The general approach is the same that was adopted by the Guide to the Expression of Uncertainty in Measurement (GUM): quantities whose values are surrounded by uncertainty are modeled as random variables, which enables the application of a wide range of techniques from probability and statistics to the evaluation of measurement uncertainty. All the methods presented are illustrated with examples involving real measurement results from a wide range of fields of chemistry and related sciences, ranging from classical analytical chemistry as practiced at the beginning to the 20th century, to contemporary studies of isotopic compositions of the elements and clinical trials. The supplementary material offers profusely annotated computer codes that allow the readers to reproduce all the calculations underlying the results presented in the examples.

Development of a polarimetric thermal imager calibration method

Measurement of thermal imager characteristics is important for the reliable and efficient operation of the device in various fields, including science, medicine, and industry. Incorrect measurements can lead to errors, which can be critical, especially for military-grade thermal imagers.
 This article is dedicated to developing a method for monitoring the output parameters of polarimetric thermal imagers based on calibration. During calibration, the following operations are proposed: visual inspection, functionality check, measurement of polarimetric thermal imager parameters, and evaluation of measurement uncertainties. In this article, the controlled parameters of the polarimetric thermal imager are the measured for device temperature and NETD, Noise Equivalent Temperature Difference. For these parameters, a measurement model, a measurement function, and an uncertainty budget have been developed. The uncertainty budget includes only the main and most influential uncertainty components. This methodology can only be used for one type of polarimetric thermal imager, where the determination of the radiation polarization state is achieved by rotating a phase plate.

MEASUREMENT UNCERTAINTY EVALUATION OF THE WIND SPEED IN THE ATMOSPHERIC BOUNDARY LAYER

A method for measuring wind speed by the trajectory of an acoustic package under the influence of air flows in the boundary atmospheric layer is developed. Model equations for measurement components of wind speed evaluation are ob- tained. For each of the components, an equation for the combined standard uncertainty is written, sensitivity coefficients are calcu- lated for input quantities, and uncertainty budgets are constructed. The last can serve as the basis for creating a software tool for measurement uncertainty evaluation.

A comparative investigation for flatness and parallelism measurement uncertainty evaluation using laser interferometry and image processing

A comparative investigation for flatness and parallelism measurement uncertainty evaluation using laser interferometry and image processing

Evaluation of Uncertainty in Measurement for Magnification Error of Metallographic Microscope Objective Lens

Propose a method for evaluating the measurement uncertainty of magnification error in metallographic microscope objective lens. Establish a measurement uncertainty evaluation model based on calibration methods and analyse the sources of each uncertainty. Combining measurement examples, this article elaborates on the evaluation of uncertainty in the measurement of magnification error of metallographic microscope objective lens.

Simultaneous Quantification of Two Neonicotinoids Using QuEChERS-LC-MS/MS in Moroccan Spearmint (Mentha Spicata.L): Qualimetry of the Method by Uncertainty Estimation Using Generalized Pivotal Quantities Approach and Monte Carlo Simulation.

Neonicotinoids (NEOs) are used for the phytosanitary treatment of Mentha Spicata.L crops, and this practice requires precise control of these harmful substances at very low concentrations. The objective of this study is to apply an approach allowing simultaneously validation and evaluation of measurement uncertainty based on total error methodology, in order to accurately quantify the presence of two NEOs in Mentha Spicata.L utilizing a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS)-LC-MS/MS methodology. The quantification of imidacloprid and acetamiprid employing a QuEChERS extraction method, coupled with LC-MS/MS, ensuring the accuracy of the analytical method and managing the risks associated with its routine use.A complete and exhaustive validation approach based on the "β-content, γ-confidence" tolerance interval was used for the uncertainty assessment, using the generalized pivot quantity (GPQ) concept and Monte Carlo simulation, which avoids the need for additional data while achieving intermediate precision for each concentration level within predetermined acceptable limits. The validation procedure is based on the choice of a quadratic model for the two NEOs, allowing the validation of acetamiprid and imidacloprid by LC-MS/MS assay within the range of working concentration. The flexibility of the uncertainty profile intervals was demonstrated with a variation in β-content values (66.7, 80, and 90%) and risk values (10 and 5%), which remained within the acceptability limits of 20%, and the relative expanded uncertainty did not exceed 15 and 11%. A QuEChERS-LC-MS/MS method for the analysis of two NEOs has been successfully fully validated using the uncertainty profile strategy. Implementation of an overall validation strategy, which involves both the validation and uncertainty assessment known as the uncertainty profile, for the quantification of two important NEOs in Mentha Spicata.L using QuEChERS-LC-MS/MS. This qualimetric approach has been conducted by computing the measurement uncertainty of the method utilizing data from analytical validation under conditions of intermediate precision at each level of concentration without additional effort. After that we have demonstrated the flexibility of this strategy for the LC-MS/MS quantification of acetamiprid and imidacloprid, using a decision tool that enables the choice and modification of β-content and γ-confidence values.

Certification of extension tubes for medical use according to TIS 2385-2551

The extension tube is a medical device for delivering substances into or out of the body through blood vessels of the patient. To ensure the safety of users and promote the domestic production, the industrial product standard of extension tubes was established as Thai Industrial Standard (TIS) No. 2385-2551: Extension tubes for medical use. Bever Medical Industry (BMI) is a medical device company that manufactures and markets medical supplies for single use. At present, the overall physical requirements standard of extension tubes has not been accredited according to ISO/IEC 17025. This study aims to certify the physical test of extension tubes for medical use and to implement the laboratory quality management system according to ISO/IEC 17025. We set up a laboratory to perform the physical test of extension tubes according to TIS 2385-2551. The measuring equipment was applied appropriately and calibrated by accredited laboratories to ISO/IEC17025 related to metrological traceability. The established laboratory performed the evaluation of measurement uncertainty for some testing and reported the results to the customer as a test certification report. In this study, a total of 1.75 million pieces of extension tubes have been certified the quality improvements. Therefore, it is valuable for entrepreneurs, importers, and exporters in both domestic and international markets.

Measurement uncertainty for < 905 > Uniformity of Dosage Units tests using Monte Carlo and bootstrapping methods – Uncertainties arising from sampling and analytical steps

Uniformity of dosage unit (UDU) test is widely used to assess the quality, safety, and effectiveness of dosage forms in unit doses. An increased variability of the amount of drug (API – Active Pharmaceutical Ingredient) in each dose unit may lead to low quality, unsafety, and ineffective medicines. The aim of this work was to evaluate the measurement uncertainty associated with the acceptance value (AV) using the Monte Carlo and Bootstrapping methods, as well as to estimate the risk of false decisions regarding compliance/non-compliance due to uncertainty. Haloperidon 5 mg tablets and ofloxacin 200 mg tablets were subject to content uniformity (CU) and weight variation (WV) tests, respectively. Measurement uncertainty evaluation of UDU tests considered both uncertainties arising from sampling analytical steps. Uncertainty values were quantified using Monte Carlo (sampling) or bootstrapping (resampling) methods. Confidence intervals at 95% confidence level (CI95%) for AV value obtained for haloperidol 5 mg tablets were found to between 8.1 and15.8 and between 8.1 and 16.9 for Boostrapping and Monte Carlo methods, respectively. There is an increased risk of false conformity assessment for haloperidol UDU test (6.5% and 12.1% risk values for Bootstrapping and Monte Carlo methods). Considering the ofloxacin 200 mg tablets, the CI95% for AV value were found to be between 4.0 and 11.3 and between 4.9 and 11.4 for Bootstrapping and Monte Carlo methods, respectively. Uncertainty arising from sampling and analytical steps were both relevant to the overall uncertainty of AV values. Measurement uncertainty evaluation provided relevant information to support conformity assessments with a reduced risk of false decision making.