Difference between calibration and practical force proving instruments

2021 ◽  
Vol 26 (1) ◽  
pp. 67-77
Author(s):  
Seif M. Osman ◽  
Gouda M. Mahmoud ◽  
Abdulelah A. Binown ◽  
Hamad Alghamdi
Keyword(s):  
Relative Error ◽  
Uncertainty Estimation ◽  
Load Cell ◽  
Expanded Uncertainty ◽  
Cell Capacity ◽  
Repeatability Error ◽  
Load Cells ◽  
Repeatability And Reproducibility ◽  
The Difference ◽  
Calibration Time

This is an experimental work on seventy load cells which aims to highlight the difference between results out of force, proving instruments calibration according to ISO 376:2011 and its practical use. It spots on the difference between the relative error of repeatability and reproducibility and their contributions on load cells classifications, uncertainty estimation and calibration time. Results show that there is no significant effect for relative error of repeatability on load cell classification, ignoring the relative repeatability error in estimating the relative expanded uncertainty lead to decrease with values between 1 ppm and 270 ppm in the range from 20 % to 50 % of load cell capacity and by values between 1 ppm and 183 ppm in the range from 50 % to 100 % of the load cell capacity. It is concluded that performing measurements to calculate the relative error of repeatability is not effective in the normal calibration process for the examined seventy load cells, further measurements over subsequent years are recommended to ensure results reproducibility aiming to generalize the conclusion and recommend measurements for the relative repeatability error for load cell conformity assessment after manufacturing.

UNCERTAINTY OF THE MEASUREMENTS RESULTS OF THE CHEMICAL COMPOSITION AND ITS METHODS ASSESSMENT

2021 ◽  
pp. 84-91
Author(s):  
F.N. Karachevtsev ◽  
◽  
A.F. Letov ◽  
A.V. Slavin ◽  
◽  
...  
Keyword(s):  
Standard Sample ◽  
Measurement Methods ◽  
Measuring Instrument ◽  
Uncertainty Of Measurement ◽  
Expanded Uncertainty ◽  
Regulatory Documents ◽  
Measurement Results ◽  
Final Measurement ◽  
Repeatability And Reproducibility ◽  
The Difference

An explanation of the difference between the uncertainty and the error of the measurement results, which is in the approach to their assessment, is given. The standard and expanded uncertainty are estimated taking into account the uncertainty at each operation to transfer the size of a physical quantity from a standard (standard sample) to a measuring instrument and during measurements. The error is estimated based on the variance of the final measurement. Methods for evaluating the uncertainty of measurement results are given depending on regulatory documents, metrological characteristics, measurement methods, such as indicators and limits of repeatability and reproducibility.

Development and Certification of Formononetin Reference Material for Quality Control of Functional Foods and Botanical Supplements

2019 ◽  
Vol 15 (5) ◽  
pp. 553-559
Author(s):  
Ningbo Gong ◽  
Baoxi Zhang ◽  
Kun Hu ◽  
Zhaolin Gao ◽  
Guanhua Du ◽  
...  
Keyword(s):  
Quality Control ◽  
Reference Material ◽  
Functional Foods ◽  
Certified Reference Materials ◽  
Coulometric Titration ◽  
Pharmaceutical Formulations ◽  
Uncertainty Estimation ◽  
Expanded Uncertainty ◽  
Scanning Calorimetry ◽  
Botanical Supplements

Background: Formononetin is a common soy isoflavonoid that can be found abundantly in many natural plants. Previous studies have shown that formononetin possesses a variety of activities which can be applied for various medicinal purposes. Certified Reference Materials (CRMs) play a fundamental role in the food, traditional medicine and dietary supplement fields, and can be used for method validation, uncertainty estimation, as well as quality control. Methods: The purity of formononetin was determined by Differential Scanning Calorimetry (DSC), Coulometric Titration (CT) and Mass Balance (MB) methods. Results: This paper reports the sample preparation methodology, homogeneity and stability studies, value assignment, and uncertainty estimation of a new certified reference material of formononetin. DSC, CT and MB methods proved to be sufficiently reliable and accurate for the certification purpose. The purity of the formononetin CRM was therefore found to be 99.40% ± 0.24 % (k = 2) based on the combined value assignments and the expanded uncertainty. Conclusion: This CRM will be a reliable standard for the validation of the analytical methods and for quality assurance/quality control of formononetin and formononetin-related traditional herbs, food products, dietary supplements and pharmaceutical formulations.

scholarly journals Open Source Digitally Replicable Lab-Grade Scales

2020 ◽  
Author(s):  
Benjamin R. Hubbard ◽  
Joshua M. Pearce
Keyword(s):  
Open Source ◽  
Low Cost ◽  
Cost Savings ◽  
Load Cell ◽  
Significant Cost ◽  
Load Cells ◽  
The Cost ◽  
Cell Data ◽  
Precision Balance ◽  
Multiple Load

This study provides designs for a low-cost, easily replicable open source lab-grade digital scale that can be used as a precision balance. The design is such that it can be manufactured for use in most labs throughout the world with open source RepRap-class material extrusion-based 3-D printers for the mechanical components and readily available open source electronics including the Arduino Nano. Several versions of the design were fabricated and tested for precision and accuracy for a range of load cells. The results showed the open source scale was found to be repeatable within 0.1g with multiple load cells, with even better precision (0.01g) depending on load cell range and style. The scale tracks linearly with proprietary lab-grade scales, meeting the performance specified in the load cell data sheets, indicating that it is accurate across the range of the load cell installed. The smallest loadcell tested(100g) offers precision on the order of a commercial digital mass balance. The scale can be produced at significant cost savings compared to scales of comparable range and precision when serial capability is present. The cost savings increase significantly as the range of the scale increases and are particularly well-suited for resource-constrained medical and scientific facilities.

scholarly journals CALCULATION OF MEASUREMENTS UNCERTAINTY AT CARRYING OUT OF BALLISTIC RESEARCHES

2017 ◽  
Vol 17 ◽  
pp. 236-245
Author(s):  
V. V. Kozhevnikov
Keyword(s):  
A Priori ◽  
Quantitative Description ◽  
Estimation Procedure ◽  
Standard Uncertainty ◽  
Uncertainty Estimation ◽  
Measured Quantity ◽  
Expanded Uncertainty ◽  
Uncertainty Sources ◽  
Multiple Observations ◽  
Uncertainty Calculation

Today one of the priority problems is receiving an accreditation certificate under the international standard ISO/IEC 17025:2006 by measurement laboratories of Expert service subdivision of the Ministry of Internal Affairs of Ukraine. One of the requirements which is shown to the accredited testing laboratories, is a presence of uncertainty estimation procedure and ability to apply it. As the ballistic researches are one of the important directions of researches which are carried out in the expert subdivisions, therefore the paper is devoted to the consideration ofa question of uncertainty calculation in such measurements. In the mathematical statistics two types of paramètres which characterize dispersion of not correlated random variables are known: a root-mean-square deviation and a confidential interval. As the characteristics of uncertainty they are applied under the title standard and expanded uncertainty. An elementary estimation of measurements result and its uncertainty is carried out in such an order: description of the measured quantity; revealing of uncertainty sources; quantitative description uncertainty constituents (there are estimated uncertainty constituents which can be received a posteriori or a priori); calculation of standard uncertainty of each source, total standard uncertainty and expanded uncertainty. A posterior estimation is possible only in the case of carrying out multiple observations of the measured quantity (standard uncertainty of type A). An a priori estimation is carried out when multiple observations are not performed. In this case it’s necessary to use the information received from the measurements performed before, from the passport data on the facilities ofmeasuring technics orfrom reference books (standard uncertainty of type B). Short consideration of uncertainty concept, elucidation of the basic stages measurements result estimation and its uncertainty gives the chance to transform the theoretical knowledge into practical application of uncertainty estimation on examples of measurements uncertainty calculation during carrying out ballistic ammunition researches by two different ways.

scholarly journals Prototype Mesin Pengantar Barang Otomatis Menggunakan Load Cell Berbasis Robot Line Follower

2018 ◽  
Vol 10 (1) ◽  
pp. 23-29
Author(s):  
Dwi Budi Susilo ◽  
Hari Wibawanto ◽  
Anggraini Mulwinda
Keyword(s):  
Load Cell ◽  
Load Testing ◽  
White Line ◽  
Photo Diode ◽  
Testing Data ◽  
Data Output ◽  
On Line ◽  
The Difference ◽  
Development Methods ◽  
Prototype Design

Overloaded condition in the product porter like hand pallet, hand stacker, forclift, and etc, can causes damage and terrible accident in the machine operator. This research aim to build a prototype of porter machine that can prevent overloaded condition through the reading of load cell and photo diode sensor to guide the line follower direction. Research and development methods are used with the systematic writing are background of study and problems, prototype design and validation, testing, taking and analysis of the data. Output of the research is a prototype of porter machine using load cell sensor based on line follower robot. The Result of the load cell reading is compared to SF-400 weigher, and found the difference amount 0.117%. The load testing data of automatic moving trigger is 1 gram until 2999 gram. The Overload condition warning is active while the load is more than 3000 gram. The data reading of the photo diode on the black line is running succesfully, however on the white line with orange color is found some error.

A Load Cell System in Foot Pressure Analysis

1982 ◽  
Vol 11 (3) ◽  
pp. 121-122 ◽  
Author(s):  
W V James ◽  
J F Orr ◽  
T Huddleston
Keyword(s):  
Low Cost ◽  
Cell System ◽  
Load Cell ◽  
Foot Pressure ◽  
Cost System ◽  
Pressure Sensitive ◽  
Low Profile ◽  
Load Cells ◽  
Pressure Analysis

A method of displaying discrete areas of pressure beneath the foot has been produced. The device employs a pressure sensitive elastomer which gives quantitative readings of the pressure developed. The 512 load cells are enclosed in a low profile platform only one inch in depth which provides a low-cost system that can be employed in clinical situations.

scholarly journals Sample Sizes Needed for Specified Margins of Relative Error in the Estimates of the Repeatability and Reproducibility Standard Deviations

2005 ◽  
Vol 88 (5) ◽  
pp. 1503-1510 ◽  
Author(s):  
Foster D McClure ◽  
Jung K Lee
Keyword(s):  
Standard Deviation ◽  
Sample Size ◽  
Relative Error ◽  
Analytical Method ◽  
Actual Error ◽  
Repeatability Standard Deviation ◽  
Repeatability And Reproducibility ◽  
Standard Deviations ◽  
True Values ◽  
Addition Formulas

Abstract Sample size formulas are developed to estimate the repeatability and reproducibility standard deviations (sr and sR) such that the actual error in (sr and sR) relative to their respective true values, σr and σR, are at predefined levels. The statistical consequences associated with AOAC INTERNATIONAL required sample size to validate an analytical method are discussed. In addition, formulas to estimate the uncertainties of (sr and sR) were derived and are provided as supporting documentation.Formula for the Number of Replicates Required for a Specified Margin of Relative Error in the Estimate of the Repeatability Standard Deviation

scholarly journals Contact-free unconstraint respiratory measurements with load cells under the bed in awake healthy volunteers: breath-by-breath comparison with pneumotachography

2019 ◽  
Vol 126 (5) ◽  
pp. 1432-1441 ◽  
Author(s):  
Shiroh Isono ◽  
Natsuko Nozaki-Taguchi ◽  
Makoto Hasegawa ◽  
Shinichiro Kato ◽  
Shinsuke Todoroki ◽  
...  
Keyword(s):  
Respiratory Rate ◽  
Human Subjects ◽  
Load Cell ◽  
The Body ◽  
Phase Changes ◽  
Body Postures ◽  
Load Cells ◽  
Centroid Shift ◽  
Lower Load ◽  
Contact Free

Rate of respiration is a fundamental vital sign. Accuracy and precision of respiratory rate measurements with contact-free load cell sensors under the bed legs were assessed by breath-by-breath comparison with the pneumotachography technique during two different dynamic breathing tasks in 16 awake human adults resting on the bed. The subject voluntarily increased and decreased the respiratory rate between 4 and 16 breaths/min ( n = 8) and 10 and 40 breaths/min ( n = 8) at every 2 breaths in 6 different lying postures such as supine, left lateral, right lateral, and 30, 45, and 60° sitting postures. Reciprocal phase changes of the upper and lower load cell signals accorded with the respiratory phases indicating respiratory-related shifts of the centroid along the long axis of the bed. Bland-Altman analyses revealed 0.66 and 1.59 breaths/min standard deviation differences between the techniques (limits of agreement: −1.22 to 1.36 and −2.96 to 3.30) and 0.07 and 0.17 breaths/min fixed bias differences (accuracy) (confidence interval: 0.04 to 0.10 and 0.12 to 0.22) for the mean respiratory rates of 10.5 ± 3.7 and 24.6 ± 8.9 breaths/min, respectively, regardless of the body postures on the bed. Proportional underestimation by this technique was evident for respiratory rates >40 breaths/min. Sample breath increase up to 10 breaths improved the precision from 1.59 to 0.26 breaths/min. Abnormally faster and slower respirations were accurately detected. We conclude that contact-free unconstraint respiratory rate measurements with load cells under the bed legs are accurate and may serve as a new clinical and investigational tool. NEW & NOTEWORTHY Four load cells placed under the bed legs successfully captured a centroid shift during respiration in human subjects lying on a bed. Breath-by-breath comparison of the breaths covering a wide respiratory rate range by pneumotachography confirmed reliability of the contact-free unconstraint respiratory rate measurements by small standard deviations and biases regardless of body postures. Abnormally faster and slower respirations were accurately detected. This technique should be an asset as a new clinical and investigational tool.

Measuring Uncertainty Using Different Approaches: A Case Study for Acetaminophen Quantification

2016 ◽  
Vol 99 (3) ◽  
pp. 612-617 ◽  
Author(s):  
Fabiane Lacerda Francisco ◽  
Alessandro Morais Saviano ◽  
Felipe Rebello Lourenço
Keyword(s):  
Measurement Uncertainty ◽  
Uncertainty Estimation ◽  
Pharmaceutical Drug ◽  
Drug Products ◽  
Pharmaceutical Equivalence ◽  
Reproducibility Study ◽  
Repeatability And Reproducibility ◽  
Analytical Result ◽  
Measurement Uncertainty Estimation

Abstract Investigation of out-of-specification analytical results is laborious, time-consuming, and costly and must be well documented. However, an analytical result is not complete unless reported with its measurement uncertainty. Here, we compare four different approaches for measurement uncertainty estimation used in acetaminophen quantification in pharmaceutical drug products. Measurement uncertainties were estimated using a repeatability and reproducibility study, Eurachem/Citac guidelines, Monte Carlo simulations, and a spreadsheet method. These different approaches provided similar results. However, they differed by the sources of uncertainties considered, by the procedures of calculation, and by the effort required in routine applications. Nevertheless, all four approaches were successful in assessing conformity of acetaminophen content in pharmaceutical drug products and may be used in assessing pharmaceutical equivalence.

Sign in / Sign up

Export Citation Format

Share Document