Pub Date : 1900-01-01DOI: 10.51843/wsproceedings.2013.57
M. Kuster
Metrologists may obtain Type B uncertainties from such engineering estimates as “The error falls within 2 units 50% of the time.” The procedure requires selecting an appropriate distribution and determining its standard deviation in terms of the containment limits and probability. The latest revision of NCSLI Recommended Practice RP-12, “Determining and Reporting Measurement Uncertainty”, provides such equations for the normal, student’s t, quadratic, cosine, triangular, trapezoidal, u-shaped, and utility distributions. This paper summarizes the Type B estimation procedure, presents the previously unknown quadratic distribution solution discovered during RP-12 development for symmetric, asymmetric, and single-sided containment limits, and gives example uses.
{"title":"A Closed-Form Solution for Quadratic Distribution Uncetainty from Containment Limits and Probability","authors":"M. Kuster","doi":"10.51843/wsproceedings.2013.57","DOIUrl":"https://doi.org/10.51843/wsproceedings.2013.57","url":null,"abstract":"Metrologists may obtain Type B uncertainties from such engineering estimates as “The error falls within 2 units 50% of the time.” The procedure requires selecting an appropriate distribution and determining its standard deviation in terms of the containment limits and probability. The latest revision of NCSLI Recommended Practice RP-12, “Determining and Reporting Measurement Uncertainty”, provides such equations for the normal, student’s t, quadratic, cosine, triangular, trapezoidal, u-shaped, and utility distributions. This paper summarizes the Type B estimation procedure, presents the previously unknown quadratic distribution solution discovered during RP-12 development for symmetric, asymmetric, and single-sided containment limits, and gives example uses.","PeriodicalId":445779,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2013","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131529703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.51843/wsproceedings.2013.41
A. Steele, K. Hill
Since its inception in 1927, the International Temperature Scale (ITS) has changed to meet the needs of the time. The ITS protocol specifies phase transitions with assigned temperatures (the defining fixed points), defining instruments (thermometers), and interpolating (or extrapolating) equations. Since 1927, the selection of fixed points and their assigned temperatures have changed, defining instruments have been added and deleted, and the equations have become more complex. In 1990, reference functions were introduced both above and below the triple point of water, and the addition of overlapping sub-ranges increased the flexibility of realization. Over the 22 years since its introduction, the ITS-90 has served its user community well. However, its departure from thermodynamic temperature is more than is desirable for the most demanding applications. One approach is to continue making measurements on the ITS-90 (T90), and then correct the temperatures for better accord with thermodynamic temperature (T) using the Consultative Committee for Thermometry’s best estimates of (T - T90). Alternatively, these shortcomings can be addressed in a one-step process, through an evolutionary change that maintains the familiar mathematical structure of the ITS-90, by updating the coefficients of the reference functions and the temperatures of the defining fixed points. This route to updating the ITS has relatively modest requirements for implementation. The impact on embedded instrumentation is minimal - requiring only an updating of the coefficients of the reference functions and not a complete reworking of the mathematics.
{"title":"A Proposal to Update the International Temperature Scale","authors":"A. Steele, K. Hill","doi":"10.51843/wsproceedings.2013.41","DOIUrl":"https://doi.org/10.51843/wsproceedings.2013.41","url":null,"abstract":"Since its inception in 1927, the International Temperature Scale (ITS) has changed to meet the needs of the time. The ITS protocol specifies phase transitions with assigned temperatures (the defining fixed points), defining instruments (thermometers), and interpolating (or extrapolating) equations. Since 1927, the selection of fixed points and their assigned temperatures have changed, defining instruments have been added and deleted, and the equations have become more complex. In 1990, reference functions were introduced both above and below the triple point of water, and the addition of overlapping sub-ranges increased the flexibility of realization. Over the 22 years since its introduction, the ITS-90 has served its user community well. However, its departure from thermodynamic temperature is more than is desirable for the most demanding applications. One approach is to continue making measurements on the ITS-90 (T90), and then correct the temperatures for better accord with thermodynamic temperature (T) using the Consultative Committee for Thermometry’s best estimates of (T - T90). Alternatively, these shortcomings can be addressed in a one-step process, through an evolutionary change that maintains the familiar mathematical structure of the ITS-90, by updating the coefficients of the reference functions and the temperatures of the defining fixed points. This route to updating the ITS has relatively modest requirements for implementation. The impact on embedded instrumentation is minimal - requiring only an updating of the coefficients of the reference functions and not a complete reworking of the mathematics.","PeriodicalId":445779,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2013","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132619690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.51843/wsproceedings.2013.26
Marcus McNeely
The 151 Healthcare Metrology Committee currently has a membership of 185 Healthcare Metrology professionals worldwide and is one of the most active Committees in NCSLI. While this achievement is significant, we continue in further outreach to a large group of Pharmaceutical, Biotech and Medical Device Metrology professionals that are not yet aware of the benefits of participation in the 151 Committee. This paper details the committee background, purpose and activities to new Healthcare Metrology professionals and industry providers, and to new NCSLI members. All are welcome to attend and participate.
{"title":"An Overview of the NCSLI 151 Healthcare Metrology Committee","authors":"Marcus McNeely","doi":"10.51843/wsproceedings.2013.26","DOIUrl":"https://doi.org/10.51843/wsproceedings.2013.26","url":null,"abstract":"The 151 Healthcare Metrology Committee currently has a membership of 185 Healthcare Metrology professionals worldwide and is one of the most active Committees in NCSLI. While this achievement is significant, we continue in further outreach to a large group of Pharmaceutical, Biotech and Medical Device Metrology professionals that are not yet aware of the benefits of participation in the 151 Committee. This paper details the committee background, purpose and activities to new Healthcare Metrology professionals and industry providers, and to new NCSLI members. All are welcome to attend and participate.","PeriodicalId":445779,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2013","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115806031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.51843/wsproceedings.2013.58
E. Morse
Coordinate Measuring Machines (CMMs) typically undergo rigorous performance testing and calibration on a yearly basis. This annual calibration is a necessary part ensuring traceability of measurements, but there are many situations that can occur over the course of a year that result in measurement errors. Certain events, such as a 'crash' of the CMM, will result in a permanent change in the state of the CMM with the subsequent measurement errors. Other sources of error may be more subtle, such as the effects of the CMM cooling or heating over a weekend if the environmental control system is not active. The absence of interim testing data poses several problems. First, in the event that the 'as found' data for the annual calibration is well out of specification, there is no way of telling when the CMM ceased to be capable of performing measurements within the manufacturer's specifications. Second, if there are periodic errors due to temperature swings or other environmental conditions, there is no way of determining if these errors were present when a particular measurement was performed. This paper will discuss some of the common sources of CMM errors, and the types of tests that can reveal these errors. Different interim testing strategies will be evaluated with respect to the trade-off between the errors revealed and the time required to run the tests.
{"title":"Interim testing strategies for Coordinate Measuring Machines","authors":"E. Morse","doi":"10.51843/wsproceedings.2013.58","DOIUrl":"https://doi.org/10.51843/wsproceedings.2013.58","url":null,"abstract":"Coordinate Measuring Machines (CMMs) typically undergo rigorous performance testing and calibration on a yearly basis. This annual calibration is a necessary part ensuring traceability of measurements, but there are many situations that can occur over the course of a year that result in measurement errors. Certain events, such as a 'crash' of the CMM, will result in a permanent change in the state of the CMM with the subsequent measurement errors. Other sources of error may be more subtle, such as the effects of the CMM cooling or heating over a weekend if the environmental control system is not active. The absence of interim testing data poses several problems. First, in the event that the 'as found' data for the annual calibration is well out of specification, there is no way of telling when the CMM ceased to be capable of performing measurements within the manufacturer's specifications. Second, if there are periodic errors due to temperature swings or other environmental conditions, there is no way of determining if these errors were present when a particular measurement was performed. This paper will discuss some of the common sources of CMM errors, and the types of tests that can reveal these errors. Different interim testing strategies will be evaluated with respect to the trade-off between the errors revealed and the time required to run the tests.","PeriodicalId":445779,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2013","volume":"185 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131831912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.51843/wsproceedings.2013.35
K. Fritsch
In the pharmaceutical laboratory, weighing is only one step of a whole analysis chain in drug discovery and quality control; however it strongly influences the overall quality and integrity of the final result. Also in production, weighing is decisive to achieve batch uniformity and consistency, e.g. in dispensing or formulation processes. For the food industry, accurate weighing processes also act as an important contribution for two of its most demanding challenges: Increasing public health and consumer safety, and increasing productivity and competitiveness. The same or similar issues are also prevalent in other industries as the chemical, fragrance or automotive industry, and also apply for testing labs and companies focusing on contract research and manufacturing. Everywhere, accurate weighing is essential to ensure continuous adherence to predefined process requirements and to avoid a frequent source of Out of Specification results (OOS).This article introduces GWP®, the science-based global standard for efficient lifecycle management of weighing instruments. It consists of the selection of the appropriate weighing system based on the evaluation of the respective weighing process requirements, and provides scientific guidance to the user regarding calibration and testing during the instrument's lifecycle. Based primarily on the user’s weighing requirements and prevailing weighing risks, it provides a state-of-the-art strategy to reduce measurement errors and to ensure reproducibly accurate weighing results. The understanding of the particular weighing process requirements and important balance and scale properties as minimum weight is essential to select an appropriate weighing system in the framework of the design qualification. The performance qualification takes into account these requirements and risks to establish a specific routine testing scenario for the instrument. The higher the impact in case of inaccurate weighings, and the more stringent the weighing accuracy requirements are the more frequently calibration and user tests have to be carried out. However, for less risky and stringent applications, testing efforts can be reduced accordingly. Widespread misconceptions • specifically in respect to the definition of test procedures and the selection of appropriate weights for periodic performance verification • are critically analyzed. Based on scientific principles the user is guided on how to optimize his routine testing procedures and how to avoid unnecessary or even erroneous testing. Risk and life cycle management form an integrated part of the overall strategy of GWP® to bridge the gap between regulatory compliance, process quality, productivity and cost consciousness.
{"title":"GWP® - The Weighing Standard: Why We Should Challenge the Established Way We Calibrate and Test Weighing Instruments","authors":"K. Fritsch","doi":"10.51843/wsproceedings.2013.35","DOIUrl":"https://doi.org/10.51843/wsproceedings.2013.35","url":null,"abstract":"In the pharmaceutical laboratory, weighing is only one step of a whole analysis chain in drug discovery and quality control; however it strongly influences the overall quality and integrity of the final result. Also in production, weighing is decisive to achieve batch uniformity and consistency, e.g. in dispensing or formulation processes. For the food industry, accurate weighing processes also act as an important contribution for two of its most demanding challenges: Increasing public health and consumer safety, and increasing productivity and competitiveness. The same or similar issues are also prevalent in other industries as the chemical, fragrance or automotive industry, and also apply for testing labs and companies focusing on contract research and manufacturing. Everywhere, accurate weighing is essential to ensure continuous adherence to predefined process requirements and to avoid a frequent source of Out of Specification results (OOS).This article introduces GWP®, the science-based global standard for efficient lifecycle management of weighing instruments. It consists of the selection of the appropriate weighing system based on the evaluation of the respective weighing process requirements, and provides scientific guidance to the user regarding calibration and testing during the instrument's lifecycle. Based primarily on the user’s weighing requirements and prevailing weighing risks, it provides a state-of-the-art strategy to reduce measurement errors and to ensure reproducibly accurate weighing results. The understanding of the particular weighing process requirements and important balance and scale properties as minimum weight is essential to select an appropriate weighing system in the framework of the design qualification. The performance qualification takes into account these requirements and risks to establish a specific routine testing scenario for the instrument. The higher the impact in case of inaccurate weighings, and the more stringent the weighing accuracy requirements are the more frequently calibration and user tests have to be carried out. However, for less risky and stringent applications, testing efforts can be reduced accordingly. Widespread misconceptions • specifically in respect to the definition of test procedures and the selection of appropriate weights for periodic performance verification • are critically analyzed. Based on scientific principles the user is guided on how to optimize his routine testing procedures and how to avoid unnecessary or even erroneous testing. Risk and life cycle management form an integrated part of the overall strategy of GWP® to bridge the gap between regulatory compliance, process quality, productivity and cost consciousness.","PeriodicalId":445779,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2013","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132538917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.51843/wsproceedings.2013.39
Joshua Biggar, Fluke Calibration
The forced-balanced fused-quartz Bourdon tube (QBT) technology is a proven pressure measurement method, which has been used in the metrology field for over 50 years. In the summer of 2010, Fluke Calibration acquired Ruska Instrument Corporation from General Electric’s Sensing and Technologies division which added this unique, high-performance pressure measurement technology to the Fluke Calibration family of pressure products. The celebrated pedigrees in Fluke Calibration’s pressure coterie that employ QBT technology are the 7000 Series pressure products. 7000 Series pressure controllers and indicators, descend from a heritage of unmatched performance and residence in the metrology community. This paper aims at explaining the unique facets of QBT technology, basis of operation and the uncertainty classes available.
{"title":"An Uncertainty Analysis of Fluke Calibration Fused-Quartz Bourdon Tube Pressure Products","authors":"Joshua Biggar, Fluke Calibration","doi":"10.51843/wsproceedings.2013.39","DOIUrl":"https://doi.org/10.51843/wsproceedings.2013.39","url":null,"abstract":"The forced-balanced fused-quartz Bourdon tube (QBT) technology is a proven pressure measurement method, which has been used in the metrology field for over 50 years. In the summer of 2010, Fluke Calibration acquired Ruska Instrument Corporation from General Electric’s Sensing and Technologies division which added this unique, high-performance pressure measurement technology to the Fluke Calibration family of pressure products. The celebrated pedigrees in Fluke Calibration’s pressure coterie that employ QBT technology are the 7000 Series pressure products. 7000 Series pressure controllers and indicators, descend from a heritage of unmatched performance and residence in the metrology community. This paper aims at explaining the unique facets of QBT technology, basis of operation and the uncertainty classes available.","PeriodicalId":445779,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2013","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123476441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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