Pub Date : 2021-12-01DOI: 10.51843/wsproceedings.2020.04
H. W. Lai
This paper describes a measurement procedure developed by the Standards and Calibration Laboratory (SCL) for measuring the parameters of single phase 50 Ω/50 μH + 5 Ω V-network type Line Impedance Stabilization Networks (LISN) or Artificial Mains Networks (AMN) specified in the International Standard CISPR 16-1-2, which are the impedance at the EUT port, the isolation between the power port and the receiver port, and the voltage division factor between the EUT port and the receiver port. The corresponding measurement models and evaluation of measurement uncertainties are presented. Characterization method of in-house developed adapters for BS1363 type plug and socket is also presented.
{"title":"Calibration of Line Impedance Stabilization Network / Artificial Mains Network in accordance with CISPR 16-1-2 Ed 2.1 2017-11","authors":"H. W. Lai","doi":"10.51843/wsproceedings.2020.04","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.04","url":null,"abstract":"This paper describes a measurement procedure developed by the Standards and Calibration Laboratory (SCL) for measuring the parameters of single phase 50 Ω/50 μH + 5 Ω V-network type Line Impedance Stabilization Networks (LISN) or Artificial Mains Networks (AMN) specified in the International Standard CISPR 16-1-2, which are the impedance at the EUT port, the isolation between the power port and the receiver port, and the voltage division factor between the EUT port and the receiver port. The corresponding measurement models and evaluation of measurement uncertainties are presented. Characterization method of in-house developed adapters for BS1363 type plug and socket is also presented.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133944515","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 : 2021-12-01DOI: 10.51843/wsproceedings.2020.15
L. Callegaro
Electrical impedance is one of the most commonly measured electrical quantities and there is a wide variety of impedance meters commercially available. Electrical calibration laboratories usually use sets of artefact impedance standards to calibrate these meters. The traceability chain for electrical impedance is described with a particular emphasis on the use of impedance bridges to calibrate the impedance standards themselves. Up to now, coaxial transformer ratio bridges with outstanding accuracy have been used for this purpose, but these have a number of practical disadvantages. It is shown that digital impedance bridges, which use digital techniques to provide the accurate voltage ratios needed for bridge balancing, offer a viable alternative to transformer ratio bridges. The principles of operation of source-based and sampling-based impedance bridges are described. A joint research project whose aim is to show that digital impedance bridges provide, even for a laboratory with limited resources and expertise, a practical means of calibrating impedance standards at the parts per million level of accuracy is introduced. A source-based digital impedance bridge, designed and constructed within the project, is described and some preliminary measurement results presented.
{"title":"Maintaining a Local Reference Scale for Electrical Impedance by Means of a Digital Impedance Bridge","authors":"L. Callegaro","doi":"10.51843/wsproceedings.2020.15","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.15","url":null,"abstract":"Electrical impedance is one of the most commonly measured electrical quantities and there is a wide variety of impedance meters commercially available. Electrical calibration laboratories usually use sets of artefact impedance standards to calibrate these meters. The traceability chain for electrical impedance is described with a particular emphasis on the use of impedance bridges to calibrate the impedance standards themselves. Up to now, coaxial transformer ratio bridges with outstanding accuracy have been used for this purpose, but these have a number of practical disadvantages. It is shown that digital impedance bridges, which use digital techniques to provide the accurate voltage ratios needed for bridge balancing, offer a viable alternative to transformer ratio bridges. The principles of operation of source-based and sampling-based impedance bridges are described. A joint research project whose aim is to show that digital impedance bridges provide, even for a laboratory with limited resources and expertise, a practical means of calibrating impedance standards at the parts per million level of accuracy is introduced. A source-based digital impedance bridge, designed and constructed within the project, is described and some preliminary measurement results presented.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130056425","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.2020.11
F. Emms
A new portable voltage transformer (VT) calibration system has been developed, based on an existing fixed laboratory system. The existing system is based on a high voltage compressed gas capacitor in the upper arm of a voltage divider, and a range of precision air capacitors in the lower arm, with the errors being balanced via the use of inductive voltage dividers. The new system utilises the same high voltage compressed gas capacitor in the upper arm but in the lower arm uses small, class 1, multi-layer ceramic capacitors. Instead of balancing the system with inductive voltage dividers, a direct measurement of the VT errors is made with the use of an integrating amplifier and two digital multimeters (DMMs). One DMM measures the secondary voltage and the other measures the relative phase and amplitude of the error voltage from an integrating amplifier. Using a VT with the nominal ratio of 10:1, and the ability of switching several of the lower arm ceramic capacitors into the upper arm, and then following a sequence of measurements, all the relative capacitance values can be calculated using a mathematical build-up process. The new portable VT calibration system has achieved a typical measurement uncertainty for voltage error and phase displacement of better than 0.003% and 0.003 crad respectively. It can test VTs with applied primary voltages from 30 V to 220 kV, and secondary voltages from 10 V to 300 V, with the ratio settings of the capacitive divider in the range of 0.1 to 2200. The system has been optimised for operating at 50 Hz and 60 Hz, but theoretically it could be used for higher frequencies.
{"title":"Measurement of Voltage Transformer Errors using a Self-calibrating Multi-ratio Capacitive Divider System","authors":"F. Emms","doi":"10.51843/wsproceedings.2020.11","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.11","url":null,"abstract":"A new portable voltage transformer (VT) calibration system has been developed, based on an existing fixed laboratory system. The existing system is based on a high voltage compressed gas capacitor in the upper arm of a voltage divider, and a range of precision air capacitors in the lower arm, with the errors being balanced via the use of inductive voltage dividers. The new system utilises the same high voltage compressed gas capacitor in the upper arm but in the lower arm uses small, class 1, multi-layer ceramic capacitors. Instead of balancing the system with inductive voltage dividers, a direct measurement of the VT errors is made with the use of an integrating amplifier and two digital multimeters (DMMs). One DMM measures the secondary voltage and the other measures the relative phase and amplitude of the error voltage from an integrating amplifier. Using a VT with the nominal ratio of 10:1, and the ability of switching several of the lower arm ceramic capacitors into the upper arm, and then following a sequence of measurements, all the relative capacitance values can be calculated using a mathematical build-up process. The new portable VT calibration system has achieved a typical measurement uncertainty for voltage error and phase displacement of better than 0.003% and 0.003 crad respectively. It can test VTs with applied primary voltages from 30 V to 220 kV, and secondary voltages from 10 V to 300 V, with the ratio settings of the capacitive divider in the range of 0.1 to 2200. The system has been optimised for operating at 50 Hz and 60 Hz, but theoretically it could be used for higher frequencies.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"565 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":"132491077","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.2020.05
Colin Delker, Mike Roberts, Amaru Robinson, O. Solomon
Every calibration laboratory creates calibration certificates that report technical and operational information about a device. Frequently, calibration certificates are issued in Portable Document Format (PDF) with little concern over whether recipients can electronically extract and use the calibration data at their facility. Sometimes data is saved as an image within the PDF forcing the use of optical character recognition or manual transcription to extract any information. These practices effectively lock the data and make it difficult to extract automatically. Without accessible data, tasks involving multiple certificates, such as control charting or interval analysis, become impossible. A universal Measurement Information Infrastructure (MII) includes a calibration certificate in a standardized, open format that allows easy access to the data for analysis, yet can be presented in a traditional, readable form. This paper explores some proof-of-concept ideas under investigation at the Primary Standards Laboratory for such an enhanced calibration certificate. An open specification based on mature technology will ease the transition from existing information systems to new MII standards. This paper describes how to embed Extensible Markup Language (XML) data into a PDF certificate, extract the information for reuse, store calibration certificates in XML format, and extend and customize the certificate to satisfy all requirements in ISO/IEC 17025:2017(E).
每个校准实验室都会创建校准证书，报告有关设备的技术和操作信息。校准证书通常以可携式文件格式(Portable Document Format, PDF)发出，很少考虑接收人能否在其设施内以电子方式提取和使用校准数据。有时数据被保存为PDF中的图像，迫使使用光学字符识别或手动转录来提取任何信息。这些做法有效地锁定了数据，使自动提取数据变得困难。如果没有可访问的数据，涉及多个证书的任务(如控制图表或间隔分析)就不可能完成。通用测量信息基础设施(MII)包括一个标准化的、开放格式的校准证书，允许方便地访问数据进行分析，但可以以传统的、可读的形式呈现。本文探讨了主要标准实验室正在研究的一些概念验证想法，以获得这种增强的校准证书。基于成熟技术的开放规范将简化从现有信息系统到新的信息工业标准的过渡。本文介绍了如何将可扩展标记语言(Extensible Markup Language, XML)数据嵌入到PDF证书中，提取用于重用的信息，以XML格式存储校准证书，并对证书进行扩展和定制，以满足ISO/IEC 17025:2017(E)的所有要求。
{"title":"Exploration of a Data-Enhanced Calibration Certificate as Part of a Complete Measurement Information Infrastructure","authors":"Colin Delker, Mike Roberts, Amaru Robinson, O. Solomon","doi":"10.51843/wsproceedings.2020.05","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.05","url":null,"abstract":"Every calibration laboratory creates calibration certificates that report technical and operational information about a device. Frequently, calibration certificates are issued in Portable Document Format (PDF) with little concern over whether recipients can electronically extract and use the calibration data at their facility. Sometimes data is saved as an image within the PDF forcing the use of optical character recognition or manual transcription to extract any information. These practices effectively lock the data and make it difficult to extract automatically. Without accessible data, tasks involving multiple certificates, such as control charting or interval analysis, become impossible. A universal Measurement Information Infrastructure (MII) includes a calibration certificate in a standardized, open format that allows easy access to the data for analysis, yet can be presented in a traditional, readable form. This paper explores some proof-of-concept ideas under investigation at the Primary Standards Laboratory for such an enhanced calibration certificate. An open specification based on mature technology will ease the transition from existing information systems to new MII standards. This paper describes how to embed Extensible Markup Language (XML) data into a PDF certificate, extract the information for reuse, store calibration certificates in XML format, and extend and customize the certificate to satisfy all requirements in ISO/IEC 17025:2017(E).","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"13 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":"126597681","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.2020.16
N. Rogge
The Planck-Balance (PB) is a table-top Kibble balance that was developed in a cooperation between the Physikalisch-Technische Bundesanstalt (PTB) and the Technische Universität Ilmenau (TUIL). The PB2 version of this system aims for a mass range from 1 mg to 100 g with uncertainties corresponding to class E2 mass standards as described in OIML-R111. In order to reduce the costs of the system, it is mostly set up by using commercially available standard parts and operates in air. A modified EMFC load cell is used to guide and drive the coil that is utilized in the Kibble experiment, while a homodyne interferometer system measures the displacement of the coil. The induced voltage is measured by a calibrated digital multimeter, which is also used to measure the voltage drop caused by the compensation current that is necessary to balance the system when a weight under test is applied. The paper presents the main components of the system while evaluating the different uncertainty contributions to the calibration of a mass standard. Recent experiments are presented that show the possibilities of a direct implementation of the new kilogram definition on the uncertainty level of class E2 mass standards.
{"title":"Current status of the PB2 Planck-Balance ","authors":"N. Rogge","doi":"10.51843/wsproceedings.2020.16","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.16","url":null,"abstract":"The Planck-Balance (PB) is a table-top Kibble balance that was developed in a cooperation between the Physikalisch-Technische Bundesanstalt (PTB) and the Technische Universität Ilmenau (TUIL). The PB2 version of this system aims for a mass range from 1 mg to 100 g with uncertainties corresponding to class E2 mass standards as described in OIML-R111. In order to reduce the costs of the system, it is mostly set up by using commercially available standard parts and operates in air. A modified EMFC load cell is used to guide and drive the coil that is utilized in the Kibble experiment, while a homodyne interferometer system measures the displacement of the coil. The induced voltage is measured by a calibrated digital multimeter, which is also used to measure the voltage drop caused by the compensation current that is necessary to balance the system when a weight under test is applied. The paper presents the main components of the system while evaluating the different uncertainty contributions to the calibration of a mass standard. Recent experiments are presented that show the possibilities of a direct implementation of the new kilogram definition on the uncertainty level of class E2 mass standards.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"64 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":"126139337","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.2020.01
S. Stahley
3D Scanning uses several non-contact measurement technologies to create a “spatial point cloud” that represents a virtual 3D surface. Once created this point cloud can then be analyzed in several ways to create everything from a Virtual Reality tour of a Cummins plant to reverse engineering apart from an early Cummins engine. This paper will discuss the role Measurement Science has in selecting the right types of measurement technologies and analysis tools being used at Cummins to digitize our plants in support of Industry 4.0.
{"title":"3D Measurement Technologies","authors":"S. Stahley","doi":"10.51843/wsproceedings.2020.01","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.01","url":null,"abstract":"3D Scanning uses several non-contact measurement technologies to create a “spatial point cloud” that represents a virtual 3D surface. Once created this point cloud can then be analyzed in several ways to create everything from a Virtual Reality tour of a Cummins plant to reverse engineering apart from an early Cummins engine. This paper will discuss the role Measurement Science has in selecting the right types of measurement technologies and analysis tools being used at Cummins to digitize our plants in support of Industry 4.0.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"41 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":"123337877","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.2020.07
G. Granger, Chantal Prevost
We experimentally determine the temperature coefficients of direct voltage reference standards known as Fluke model 732B at the National Research Council Canada. Two units, used as references, are maintained at ambient temperature for the entire measurement duration of 4 weeks. Ambient conditions are monitored using calibrated environmental data loggers. The standards under test are placed into a temperature-regulated air bath, where calibrated environmental data loggers monitor bath conditions near the voltage terminals and near the thermistor terminals. The following quantities are measured: voltage difference between standard under test and reference standard for both 10 V and 1.018 V channels, thermistor resistance of all standards, environmental conditions both inside and outside the air bath. The air bath temperature is set to stay on alternate weeks at higher and lower temperatures following the sequence (25, 20, 25, 20) °C. The ambient temperature is between 21 and 22 °C. The entire process is repeated a second time with the locations of the standards under tests and reference standards inverted. Data analysis consists of calculating the average temperature-induced voltage and resistance changes and dividing the results by the measured temperature change to obtain the temperature coefficients. A detailed uncertainty analysis is performed. The results are compared to manufacturer specifications. The majority of our standards are better than specifications, even when taking into account the measurement uncertainties. Such experiments are beneficial, as they allow the identification of the standards with the smallest temperature coefficients to be used as direct voltage reference in client calibration services. The results can be combined into a thermistor resistance coefficient, which can be used to provide a quantitative estimate for the size of the largest temperature-induced change of resistance that has negligible effect on the voltage outputs for a given tolerance level.
{"title":"Temperature Coefficients of Direct Voltage Reference Standards at National Research Council Canada","authors":"G. Granger, Chantal Prevost","doi":"10.51843/wsproceedings.2020.07","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.07","url":null,"abstract":"We experimentally determine the temperature coefficients of direct voltage reference standards known as Fluke model 732B at the National Research Council Canada. Two units, used as references, are maintained at ambient temperature for the entire measurement duration of 4 weeks. Ambient conditions are monitored using calibrated environmental data loggers. The standards under test are placed into a temperature-regulated air bath, where calibrated environmental data loggers monitor bath conditions near the voltage terminals and near the thermistor terminals. The following quantities are measured: voltage difference between standard under test and reference standard for both 10 V and 1.018 V channels, thermistor resistance of all standards, environmental conditions both inside and outside the air bath. The air bath temperature is set to stay on alternate weeks at higher and lower temperatures following the sequence (25, 20, 25, 20) °C. The ambient temperature is between 21 and 22 °C. The entire process is repeated a second time with the locations of the standards under tests and reference standards inverted. Data analysis consists of calculating the average temperature-induced voltage and resistance changes and dividing the results by the measured temperature change to obtain the temperature coefficients. A detailed uncertainty analysis is performed. The results are compared to manufacturer specifications. The majority of our standards are better than specifications, even when taking into account the measurement uncertainties. Such experiments are beneficial, as they allow the identification of the standards with the smallest temperature coefficients to be used as direct voltage reference in client calibration services. The results can be combined into a thermistor resistance coefficient, which can be used to provide a quantitative estimate for the size of the largest temperature-induced change of resistance that has negligible effect on the voltage outputs for a given tolerance level.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"69 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":"133608263","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.2020.28
José Luis Rivera Ramírez, L. O. Becerra Santiago
The density results of a natural gas sample are presented, which were obtained by making the measurement experimentally using an oscillatory type density meter. This instrument is used in applications for research and development of measurement systems, as well as in industries. The measurement system that was designed to determine the density of natural gas was worked with pressure values within the range of 80 to 1 000 kPa and at a constant temperature of 20 ° C. The experimental results of the density of natural gas were compared with results obtained with the calculation according to ISO 9676: 2016 standard, obtaining satisfactory conclusions.
{"title":"Natural Gas Density Measurement with an Oscillator type Density meter ","authors":"José Luis Rivera Ramírez, L. O. Becerra Santiago","doi":"10.51843/wsproceedings.2020.28","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.28","url":null,"abstract":"The density results of a natural gas sample are presented, which were obtained by making the measurement experimentally using an oscillatory type density meter. This instrument is used in applications for research and development of measurement systems, as well as in industries. The measurement system that was designed to determine the density of natural gas was worked with pressure values within the range of 80 to 1 000 kPa and at a constant temperature of 20 ° C. The experimental results of the density of natural gas were compared with results obtained with the calculation according to ISO 9676: 2016 standard, obtaining satisfactory conclusions.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"37 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":"134593480","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.2020.27
Iván Espinosa Nulutagua, Octavio Icasio Hernández
According to documentary standards for the performance evaluation of Laser Trackers (LT), long length reference artifacts are required. In this paper, we discuss the design, construction, and calibration of a long length artifact called step gauge of nests (SGN). The SGN has several nests in line to place the LT probe; the two extreme nests of the SGN are at a distance of 3 m approximately. The documentary standard establishes that the gauge's length must be known no matter the orientations it takes. However, for long gauges, factors like gravitational force, fixturing forces, change in the environmental conditions, among others, deforms the gauge, and its length changes when its orientation changes. To evaluate these factors, in the design stage, we use a finite element simulation of the SGN to predict such deformations (mainly length variations between the two extreme nests). The simulation takes into account the used material, its stiffness, straightness, distribution of the nest's weight, and geometry's change of the SGN to reduce the variations in its length. For the construction stage, we describe how the SGN was manufactured and how using high module carbon fiber, we reduce the influence of the temperature factor. The results of the finite element simulation show a length variation of around 20 ppm between the horizontal and vertical SGN positions. That variation was validated with the calibration results using two different methods. The first uses the line of sight (LOS) method, which involves the same LT under evaluation. The second uses an accurate CMM, using the overlap method for calibration. The traceability of the LOS method is accomplished with the wavelength calibration of the LT interferometer; meanwhile, the overlap method uses a CMM evaluated with a laser interferometer with calibrated wavelength.
{"title":"Design, construction, and calibration of a step gauge of nests for performance evaluation of Laser Trackers","authors":"Iván Espinosa Nulutagua, Octavio Icasio Hernández","doi":"10.51843/wsproceedings.2020.27","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.27","url":null,"abstract":"According to documentary standards for the performance evaluation of Laser Trackers (LT), long length reference artifacts are required. In this paper, we discuss the design, construction, and calibration of a long length artifact called step gauge of nests (SGN). The SGN has several nests in line to place the LT probe; the two extreme nests of the SGN are at a distance of 3 m approximately. The documentary standard establishes that the gauge's length must be known no matter the orientations it takes. However, for long gauges, factors like gravitational force, fixturing forces, change in the environmental conditions, among others, deforms the gauge, and its length changes when its orientation changes. To evaluate these factors, in the design stage, we use a finite element simulation of the SGN to predict such deformations (mainly length variations between the two extreme nests). The simulation takes into account the used material, its stiffness, straightness, distribution of the nest's weight, and geometry's change of the SGN to reduce the variations in its length. For the construction stage, we describe how the SGN was manufactured and how using high module carbon fiber, we reduce the influence of the temperature factor. The results of the finite element simulation show a length variation of around 20 ppm between the horizontal and vertical SGN positions. That variation was validated with the calibration results using two different methods. The first uses the line of sight (LOS) method, which involves the same LT under evaluation. The second uses an accurate CMM, using the overlap method for calibration. The traceability of the LOS method is accomplished with the wavelength calibration of the LT interferometer; meanwhile, the overlap method uses a CMM evaluated with a laser interferometer with calibrated wavelength.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"22 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":"134282826","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.2020.25
Heather A. Wade
Labs making chemical and/or microbiological measurements have long been left out of the measurement uncertainty discussion at major physical metrology conferences. As a result, calculating measurement uncertainty for chemical and microbiological analysis can leave many physical metrologists scratching their heads in wonder. The rules we have learned for calculating electrical or dimensional uncertainties do not transfer as smoothly. The good news is that there are proven methods and guidance how to calculate measurement uncertainty for chemical and microbiological measurements. There is also guidance on what to do when measurement uncertainty cannot be calculated.
{"title":"Measurement Uncertainty for Chemistry & Microbiology","authors":"Heather A. Wade","doi":"10.51843/wsproceedings.2020.25","DOIUrl":"https://doi.org/10.51843/wsproceedings.2020.25","url":null,"abstract":"Labs making chemical and/or microbiological measurements have long been left out of the measurement uncertainty discussion at major physical metrology conferences. As a result, calculating measurement uncertainty for chemical and microbiological analysis can leave many physical metrologists scratching their heads in wonder. The rules we have learned for calculating electrical or dimensional uncertainties do not transfer as smoothly. The good news is that there are proven methods and guidance how to calculate measurement uncertainty for chemical and microbiological measurements. There is also guidance on what to do when measurement uncertainty cannot be calculated.","PeriodicalId":422993,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2020","volume":"52 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":"132764738","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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