Pub Date : 1900-01-01DOI: 10.51843/wsproceedings.2017.28
M. Bailey
A study into the effects of lead material, length and construction on measured AC Voltage. Most metrologists are familiar with the effects of lead construction and material on DC Voltage (for example EMF caused by low-quality metals) and resistance (insulation resistance causing errors on high-value resistance measurements) however much fewer are familiar with the effects that leads have upon measurements of precision AC Voltage at frequencies from 10Hz to 1MHz. This paper focusses on precision AC Voltage measurements (uncertainties of less than 100ppm) at both low and high frequencies and studies the effects of lead length, construction and materials on the resulting measurements to better evaluate the uncertainty contribution caused by leads on these measurements.
{"title":"Effects of Lead Construction and Materials on AC Voltage Measurements","authors":"M. Bailey","doi":"10.51843/wsproceedings.2017.28","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.28","url":null,"abstract":"A study into the effects of lead material, length and construction on measured AC Voltage. Most metrologists are familiar with the effects of lead construction and material on DC Voltage (for example EMF caused by low-quality metals) and resistance (insulation resistance causing errors on high-value resistance measurements) however much fewer are familiar with the effects that leads have upon measurements of precision AC Voltage at frequencies from 10Hz to 1MHz. This paper focusses on precision AC Voltage measurements (uncertainties of less than 100ppm) at both low and high frequencies and studies the effects of lead length, construction and materials on the resulting measurements to better evaluate the uncertainty contribution caused by leads on these measurements.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","volume":"273 2 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":"123718914","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.2017.02
S. Davidson
The International System of Units (SI), which provides the basis for all physical measurements, is due to be revised in 2018. The current system, defined by seven base units, will be replaced by a "New SI" where all units are defined in terms of a set of seven reference constants, to be known as the "defining constants of the SI". The aim is to provide a simpler and more fundamental definition of the entire SI, which will also dispense with the last of the definitions based on a material artifact • the international prototype kilogram. In the new SI the kilogram will be defined in terms of a fixed value of the Planck constant, h. This definition theoretically gives universal access to the unit and facilitates a robust and egalitarian mass scale, but only if sufficient laboratories are able to realise mass from the new definition. Currently the projects able to realise the mass unit to the level of accuracy required are the Kibble (watt) balance and Avogadro experiments. The present implementations of these experiments are extremely expensive, difficult to duplicate and complicated and time consuming to operate. The Kibble balance experiment, which originated at NPL in 1975, equates virtual electrical and mechanical power. Once a numerical value of h has been fixed the Kibble balance can be used to determine mass in terms of quantum electrical phenomena (the Josephson and quantum Hall effects) and measurements of velocity and local gravity. NPL has proposed improvements to the Kibble balance which have the potential to significantly reduce the cost and complexity of both constructing and operating the balance. NPL is currently working on a technology demonstrator to test the viability of the proposed improvements. A second technology demonstrator will test the viability of a Kibble balance based on a "seismometer" mechanism using flexures for both weighing and moving, and incorporating a highly stable electromagnetic “tare” system making the apparatus much less sensitive to alignment issues. This paper outlines the proposed improvements in the Kibble balance design and examine more generally the likely effect of the revision of the SI on mass metrology in the future.
{"title":"Addressing the Need for Wider Access to the SI Unit of Mass Following the Revision of the International System of Units","authors":"S. Davidson","doi":"10.51843/wsproceedings.2017.02","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.02","url":null,"abstract":"The International System of Units (SI), which provides the basis for all physical measurements, is due to be revised in 2018. The current system, defined by seven base units, will be replaced by a \"New SI\" where all units are defined in terms of a set of seven reference constants, to be known as the \"defining constants of the SI\". The aim is to provide a simpler and more fundamental definition of the entire SI, which will also dispense with the last of the definitions based on a material artifact • the international prototype kilogram. In the new SI the kilogram will be defined in terms of a fixed value of the Planck constant, h. This definition theoretically gives universal access to the unit and facilitates a robust and egalitarian mass scale, but only if sufficient laboratories are able to realise mass from the new definition. Currently the projects able to realise the mass unit to the level of accuracy required are the Kibble (watt) balance and Avogadro experiments. The present implementations of these experiments are extremely expensive, difficult to duplicate and complicated and time consuming to operate. The Kibble balance experiment, which originated at NPL in 1975, equates virtual electrical and mechanical power. Once a numerical value of h has been fixed the Kibble balance can be used to determine mass in terms of quantum electrical phenomena (the Josephson and quantum Hall effects) and measurements of velocity and local gravity. NPL has proposed improvements to the Kibble balance which have the potential to significantly reduce the cost and complexity of both constructing and operating the balance. NPL is currently working on a technology demonstrator to test the viability of the proposed improvements. A second technology demonstrator will test the viability of a Kibble balance based on a \"seismometer\" mechanism using flexures for both weighing and moving, and incorporating a highly stable electromagnetic “tare” system making the apparatus much less sensitive to alignment issues. This paper outlines the proposed improvements in the Kibble balance design and examine more generally the likely effect of the revision of the SI on mass metrology in the future.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","volume":"43 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":"123835485","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.2017.33
Michael Dobbert
When calibrating Measuring and Test Equipment (M&TE) it is often necessary to measure various points across a range. Random measurement errors can lead to noisy observations that are apparent when viewing the measurement results on a line graph. Making repeated measurements and averaging reduces the noise, but at the cost of increased measurement time. However, multiple observations are already available as a result of measuring across the range. A smoothing spline uses a spline function to fit a smoothed curve to the noisy observations producing results with less noise. The smoothing spline can be used without incurring additional measurement time. To evaluate the impact of smoothing on the uncertainty, a receiver linearity measurement was repeated fifty times, and the mean and Type A uncertainty determined. These statistics were then compared to the mean and Type A uncertainty of the smoothed data. The Type A uncertainty of the smoothed data was less than the uncertainty of the original observations by as much as fifty percent.
{"title":"Reducing Measurement Uncertainty Using a Smoothing Spline","authors":"Michael Dobbert","doi":"10.51843/wsproceedings.2017.33","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.33","url":null,"abstract":"When calibrating Measuring and Test Equipment (M&TE) it is often necessary to measure various points across a range. Random measurement errors can lead to noisy observations that are apparent when viewing the measurement results on a line graph. Making repeated measurements and averaging reduces the noise, but at the cost of increased measurement time. However, multiple observations are already available as a result of measuring across the range. A smoothing spline uses a spline function to fit a smoothed curve to the noisy observations producing results with less noise. The smoothing spline can be used without incurring additional measurement time. To evaluate the impact of smoothing on the uncertainty, a receiver linearity measurement was repeated fifty times, and the mean and Type A uncertainty determined. These statistics were then compared to the mean and Type A uncertainty of the smoothed data. The Type A uncertainty of the smoothed data was less than the uncertainty of the original observations by as much as fifty percent.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","volume":"1 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":"125719418","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.2017.09
Jennifer Fleenor
Resolution of a customer complaint is a critical component of any laboratory quality management system. This presentation will highlight a problem solving case study on the investigation, root cause identification, corrective action and implementation verification of a customer complaint initiated on the increased out-of-tolerance incidents of the customer’s thread plug inventory. The session will highlight the method employed to provide an integrated customer experience, transforming the complaint into a positive customer loyalty experience. Participants will receive useful information on the problem solving approach utilized to resolve this real-life customer complaint. Examples will include problem solving tools and the transformation of the complaint into a customer-centric system. Advice on the investigation, analysis, reporting and follow-up actions for the complaint will be shared.
{"title":"Increased Out-of-Tolerance Incidents Customer Complaint Case Study","authors":"Jennifer Fleenor","doi":"10.51843/wsproceedings.2017.09","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.09","url":null,"abstract":"Resolution of a customer complaint is a critical component of any laboratory quality management system. This presentation will highlight a problem solving case study on the investigation, root cause identification, corrective action and implementation verification of a customer complaint initiated on the increased out-of-tolerance incidents of the customer’s thread plug inventory. The session will highlight the method employed to provide an integrated customer experience, transforming the complaint into a positive customer loyalty experience. Participants will receive useful information on the problem solving approach utilized to resolve this real-life customer complaint. Examples will include problem solving tools and the transformation of the complaint into a customer-centric system. Advice on the investigation, analysis, reporting and follow-up actions for the complaint will be shared.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","volume":"45 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":"127794829","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.2017.37
M. Koike
A new automated coaxial AC bridge 10:1 for the calibration of AC resistors from 0.1 O to 100kΩ in the frequency range from 50 Hz to 10 kHz has been fabricated by Japan Electric Meters Inspection Corporation (JEMIC). The distinguishing feature of our new AC bridge is that no injection signals are required to balance the bridge circuit, that is, the voltage difference is read directly. The system is computer-controlled using a coaxial mechanical scanner for setup, and it is only necessary to select 'start' on a PC. As a result, it takes less than one minute to calibrate an AC resistor. That is, our new method enables rapid calibration of the AC bridge. The AC bridge has been evaluated by using calculable resistance standards and by comparing it with a conventional AC bridge at JEMIC. The relative expanded uncertainties of the present system have been estimated to be 15×10-6 for the in-phase component and 30×10-6 for the quadrature component at 1 kHz.
{"title":"New Automated Coaxial AC Bridge for Rapid Calibration of AC Resistors","authors":"M. Koike","doi":"10.51843/wsproceedings.2017.37","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.37","url":null,"abstract":"A new automated coaxial AC bridge 10:1 for the calibration of AC resistors from 0.1 O to 100kΩ in the frequency range from 50 Hz to 10 kHz has been fabricated by Japan Electric Meters Inspection Corporation (JEMIC). The distinguishing feature of our new AC bridge is that no injection signals are required to balance the bridge circuit, that is, the voltage difference is read directly. The system is computer-controlled using a coaxial mechanical scanner for setup, and it is only necessary to select 'start' on a PC. As a result, it takes less than one minute to calibrate an AC resistor. That is, our new method enables rapid calibration of the AC bridge. The AC bridge has been evaluated by using calculable resistance standards and by comparing it with a conventional AC bridge at JEMIC. The relative expanded uncertainties of the present system have been estimated to be 15×10-6 for the in-phase component and 30×10-6 for the quadrature component at 1 kHz.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","volume":"50 18","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113942102","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.2017.31
Ashly Carter
The paper is an introduction to the newly published ISO 17034 standard for Reference Material Producers and briefly describes the changes from ISO Guide 34 which it replaces. The paper includes a brief summary of the supporting guides associated with ISO 17034 which includes the definitions in ISO Guide 30, the requirements for statistical methods in ISO Guide 35, and the requirements for descriptive information in ISO Guide 31 related to reference material certificates, labels and supporting documentation. The paper will explain the accreditation process for Reference Material Producers and emphasize the importance of the requirements of the standard in regards to elements such as establishing metrological traceability, ensuring homogeneity and stability of the reference material, and assigning the values and associated uncertainties of the reference material. The paper also describes what a user of reference materials should consider when choosing an appropriate reference material and reviewing the supporting documentation. For example, is a certified reference material needed or is a reference material needed? What is the difference, and what sort of documentation should I expect for the different types of reference materials? In the end, the reader will walk away with a better understanding of the requirements associated with reference material producer accreditation to ISO 17034 and a better understanding of what to look for when choosing and using reference materials.
{"title":"The New ISO 17034 and Reference Material Producer Accreditation","authors":"Ashly Carter","doi":"10.51843/wsproceedings.2017.31","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.31","url":null,"abstract":"The paper is an introduction to the newly published ISO 17034 standard for Reference Material Producers and briefly describes the changes from ISO Guide 34 which it replaces. The paper includes a brief summary of the supporting guides associated with ISO 17034 which includes the definitions in ISO Guide 30, the requirements for statistical methods in ISO Guide 35, and the requirements for descriptive information in ISO Guide 31 related to reference material certificates, labels and supporting documentation. The paper will explain the accreditation process for Reference Material Producers and emphasize the importance of the requirements of the standard in regards to elements such as establishing metrological traceability, ensuring homogeneity and stability of the reference material, and assigning the values and associated uncertainties of the reference material. The paper also describes what a user of reference materials should consider when choosing an appropriate reference material and reviewing the supporting documentation. For example, is a certified reference material needed or is a reference material needed? What is the difference, and what sort of documentation should I expect for the different types of reference materials? In the end, the reader will walk away with a better understanding of the requirements associated with reference material producer accreditation to ISO 17034 and a better understanding of what to look for when choosing and using reference materials.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","volume":"33 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":"122379943","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.2017.45
J. Shaw
Extreme weather has becomes a thorny issue across the world. In agriculture, greenhouse is not only providing suitable living environment in bitter winter but also in hot summer for various kinds of crops. In the subtropical zone, using air conditioning is one of effective cooling methods, but also brings high power consumption and cost. Actually growing conditions for crops are influenced by micro climate hydrodynamic phenomena with small-scale convection. The heat-transfer of traditional air conditioning is convection through bulk cold air flow and diffusing into local growth zone. Thus, it was found drawbacks with low efficiency and high energy-consumption problems. In this presentation, the partial air conditioning with micro-environment design was proposed, and the micro climate phenomena of small-scale heat and mass transfer were also discussed. The concept of micro-environment design is to confine the cold air flow from air conditioning system and covering plant growth zone to generate an optimal environment with high uniformity and less energy-consumption. The micro-environment, design with partial air conditioning induces the small-scale flow fluctuation and contributes to rapid transfer of heat and mass in small-scales, and enhance energy efficiency. The partial air conditioning design concept could be applied with multitudinous crops, and strawberry is chosen in this study.
{"title":"Influence of Micro-Environmental Design with Partial Air Conditioning on Mass and Heat Transfer in Greenhouses","authors":"J. Shaw","doi":"10.51843/wsproceedings.2017.45","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.45","url":null,"abstract":"Extreme weather has becomes a thorny issue across the world. In agriculture, greenhouse is not only providing suitable living environment in bitter winter but also in hot summer for various kinds of crops. In the subtropical zone, using air conditioning is one of effective cooling methods, but also brings high power consumption and cost. Actually growing conditions for crops are influenced by micro climate hydrodynamic phenomena with small-scale convection. The heat-transfer of traditional air conditioning is convection through bulk cold air flow and diffusing into local growth zone. Thus, it was found drawbacks with low efficiency and high energy-consumption problems. In this presentation, the partial air conditioning with micro-environment design was proposed, and the micro climate phenomena of small-scale heat and mass transfer were also discussed. The concept of micro-environment design is to confine the cold air flow from air conditioning system and covering plant growth zone to generate an optimal environment with high uniformity and less energy-consumption. The micro-environment, design with partial air conditioning induces the small-scale flow fluctuation and contributes to rapid transfer of heat and mass in small-scales, and enhance energy efficiency. The partial air conditioning design concept could be applied with multitudinous crops, and strawberry is chosen in this study.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","volume":"27 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":"117048323","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.2017.36
R. Herrera-Basurto
The technologies of materials production with applications in various fields including food, automotive and aerospace, have begun to settle in several clusters in Mexico. Some examples of this type of manufacturing processes are adhesive, additive, thermal projection and nanotechnology. On the other hand, the implementation of the concept of industry 4.0 has brought a new way of organizing the production ways. This has generated a demand of qualified personnel with the ability to identify elements that help to provide quality criteria for lots of pieces or single pieces manufactured under the processes described above. personnel must comply the following competencies: knowledge in manufacturing process, testing and metrology. In Querétaro, México universities such as Universidad Politécnica de Santa Rosa Jáuregui (UPSRJ) and Universidad Aeronáutica en Querétaro (UNAQ) have implemented a strategy to meet this needs. This strategy includes the teaching of courses related to metrology, standardization and conformity assessment applied to the manufacturing processes. UPSRJ has a bachelor degree in Industrial Metrology Engineering, where students can have a specialized educational program in the science of measurements. While at UNAQ students can have selected measurement courses for aerospace sciences as part of the aerospace engineering master program, according to the requirements of NADCAP. A relevant situation is that several graduates of both institutions are already working in the industry in charged of the quality of manufacturing processes. These graduates already understand the importance of using the uncertainty and sensitivity of the measurements as innovative parameters for the continuous improvement of manufacturing processes.
{"title":"Exploring the Impact of Teaching Metrology in Manufacturing Processes in Mexico","authors":"R. Herrera-Basurto","doi":"10.51843/wsproceedings.2017.36","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.36","url":null,"abstract":"The technologies of materials production with applications in various fields including food, automotive and aerospace, have begun to settle in several clusters in Mexico. Some examples of this type of manufacturing processes are adhesive, additive, thermal projection and nanotechnology. On the other hand, the implementation of the concept of industry 4.0 has brought a new way of organizing the production ways. This has generated a demand of qualified personnel with the ability to identify elements that help to provide quality criteria for lots of pieces or single pieces manufactured under the processes described above. personnel must comply the following competencies: knowledge in manufacturing process, testing and metrology. In Querétaro, México universities such as Universidad Politécnica de Santa Rosa Jáuregui (UPSRJ) and Universidad Aeronáutica en Querétaro (UNAQ) have implemented a strategy to meet this needs. This strategy includes the teaching of courses related to metrology, standardization and conformity assessment applied to the manufacturing processes. UPSRJ has a bachelor degree in Industrial Metrology Engineering, where students can have a specialized educational program in the science of measurements. While at UNAQ students can have selected measurement courses for aerospace sciences as part of the aerospace engineering master program, according to the requirements of NADCAP. A relevant situation is that several graduates of both institutions are already working in the industry in charged of the quality of manufacturing processes. These graduates already understand the importance of using the uncertainty and sensitivity of the measurements as innovative parameters for the continuous improvement of manufacturing processes.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","volume":"204 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":"116183024","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: 10.1051/METROLOGY/20150003003
S. R. Rickaby, D. Highton
When an object, specifically an anemometer, is presented before a small open jet wind tunnel the flow field will be altered deflecting the flow around the anemometer creating what is commonly known as the Blockage Effect. Directly comparing a thermal anemometer with a vane anemometer in the same flow field, the velocity measured by the thermal anemometer may be significantly different to that measured by the vane anemometer as a result of blockage. In this paper we consider the blockage created by a thermal anemometer. A simple mathematical model is derived to directly compare the thermal anemometer with a primary standard vane anemometer. The calibration results obtained are compared with those obtained by the manufacturer and an ISO/IEC 17025 accredited laboratory chosen as the Reference Laboratory for the purposes of the paper. We conclude with an analysis of the results, discussing the differences in the measured output and postulating how these results may be unified.
{"title":"Determination of the Blockage Effect on a Thermal Anemometer using a Small Open Jet Wind Tunnel","authors":"S. R. Rickaby, D. Highton","doi":"10.1051/METROLOGY/20150003003","DOIUrl":"https://doi.org/10.1051/METROLOGY/20150003003","url":null,"abstract":"When an object, specifically an anemometer, is presented before a small open jet wind tunnel the flow field will be altered deflecting the flow around the anemometer creating what is commonly known as the Blockage Effect. Directly comparing a thermal anemometer with a vane anemometer in the same flow field, the velocity measured by the thermal anemometer may be significantly different to that measured by the vane anemometer as a result of blockage. In this paper we consider the blockage created by a thermal anemometer. A simple mathematical model is derived to directly compare the thermal anemometer with a primary standard vane anemometer. The calibration results obtained are compared with those obtained by the manufacturer and an ISO/IEC 17025 accredited laboratory chosen as the Reference Laboratory for the purposes of the paper. We conclude with an analysis of the results, discussing the differences in the measured output and postulating how these results may be unified.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","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":"125376146","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.2017.03
G. Tang
A submicron automated precision line scale calibration system was developed at the Standards and Calibration Laboratory (SCL) in Hong Kong. The system provided a measuring capability for line scale of range 0.01 to 750 mm with measurement uncertainty of[0.152 + (0.0005*l)2]1/2 μm (l in mm). The fully automated system used the displacement method and employed an air bearing stage driven by a piezoelectric motor. A pixel-counting system was integrated with a microscope to enhance accuracy. The system used only one laser interferometer to compensate the Abbe error in two lateral directions. Without further calculation, any angular movement leading to an Abbe error would be automatically compensated. The uncertainty contributed from Abbe effects was evaluated to be within 30nm, an error reduction of over 95 % of the Abbe effect when such an arrangement was not in place.
香港标准及校正实验所研制了一套亚微米自动精密线尺校正系统。该系统的测量范围为0.01 ~ 750 mm，测量不确定度为[0.152 + (0.0005*l)2]1/2 μm (l in mm)。全自动化系统采用位移法，采用由压电电机驱动的气浮级。像素计数系统与显微镜集成在一起以提高精度。该系统仅使用一个激光干涉仪在两个横向方向补偿阿贝误差。无需进一步计算，任何导致阿贝误差的角运动都将自动补偿。阿贝效应带来的不确定性被评估为在30nm以内，当这种安排不到位时，误差减少了超过95%的阿贝效应。
{"title":"A Submicron Automated Precision Line Scale Calibration System Developed at the Standards and Calibration Laboratory (SCL) ","authors":"G. Tang","doi":"10.51843/wsproceedings.2017.03","DOIUrl":"https://doi.org/10.51843/wsproceedings.2017.03","url":null,"abstract":"A submicron automated precision line scale calibration system was developed at the Standards and Calibration Laboratory (SCL) in Hong Kong. The system provided a measuring capability for line scale of range 0.01 to 750 mm with measurement uncertainty of[0.152 + (0.0005*l)2]1/2 μm (l in mm). The fully automated system used the displacement method and employed an air bearing stage driven by a piezoelectric motor. A pixel-counting system was integrated with a microscope to enhance accuracy. The system used only one laser interferometer to compensate the Abbe error in two lateral directions. Without further calculation, any angular movement leading to an Abbe error would be automatically compensated. The uncertainty contributed from Abbe effects was evaluated to be within 30nm, an error reduction of over 95 % of the Abbe effect when such an arrangement was not in place.","PeriodicalId":432978,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2017","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":"124770784","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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