Pub Date : 2021-12-01DOI: 10.17764/1557-2196-64.1.42
C. Taylor, B. Notohardjono, Suraush Q. Khambati, S. Canfield
In optimizing packaging design, the product’s fragility is qualified by a protype undergoing quantitative and qualitative tests that rely heavily on past knowledge and experiments. By the addition of finite element analysis (FEA), the product’s fragility can be obtained in the initial stages of product design with material characterization and simulation. FEA can predict Gs on the product as well as examine the strains, which interpret product failure more easily in the design stage. To incorporate FEA, first the foam material was measured at various strain rates under compression. Next a shipping package containing an Al block with consistent density was dropped at different heights—610 mm (24”), 915 mm (36”), and 1067 mm (42”)—to confirm the methodology. An I/O book was packaged for the final demonstration incorporating FEA with an electronic card package. In an electronic card package, the electronic assemblies are sensitive to strains on the system board. If the strains on the board are high, the assemblies’ solder connections to the board could be damaged and result in a defect during shipment. The simulations’ predicted Gs and board strains were compared to experimental drop testing results at 610 mm (24”) and 915 mm (36”). The simulation results for each sensor location were within reasonable approximation of the experimental results, verifying that FEA could be used in the initial design stages to predict the accelerations and strains for packaging development in parallel to the product design.
{"title":"Designing Electronic Card Packages Against Shipping Shock","authors":"C. Taylor, B. Notohardjono, Suraush Q. Khambati, S. Canfield","doi":"10.17764/1557-2196-64.1.42","DOIUrl":"https://doi.org/10.17764/1557-2196-64.1.42","url":null,"abstract":"\u0000 In optimizing packaging design, the product’s fragility is qualified by a protype undergoing quantitative and qualitative tests that rely heavily on past knowledge and experiments. By the addition of finite element analysis (FEA), the product’s fragility can be obtained in the initial stages of product design with material characterization and simulation. FEA can predict Gs on the product as well as examine the strains, which interpret product failure more easily in the design stage. To incorporate FEA, first the foam material was measured at various strain rates under compression. Next a shipping package containing an Al block with consistent density was dropped at different heights—610 mm (24”), 915 mm (36”), and 1067 mm (42”)—to confirm the methodology. An I/O book was packaged for the final demonstration incorporating FEA with an electronic card package. In an electronic card package, the electronic assemblies are sensitive to strains on the system board. If the strains on the board are high, the assemblies’ solder connections to the board could be damaged and result in a defect during shipment. The simulations’ predicted Gs and board strains were compared to experimental drop testing results at 610 mm (24”) and 915 mm (36”). The simulation results for each sensor location were within reasonable approximation of the experimental results, verifying that FEA could be used in the initial design stages to predict the accelerations and strains for packaging development in parallel to the product design.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44200989","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: 10.17764/1557-2196-64.1.1
Dilip Ashtekar
Currently, limited guidance is available for the contamination control of visible particles for the manufacture of sterile devices; thus, a comprehensive guidance is warranted. Sterile devices require stringent control of visible particulates to ensure proper functionality, performance assurance of sterility, reliability, patient safety, efficacy, and product quality. This paper outlines practical and science-based strategies to prevent/minimize visible particle contamination from non-process related extrinsic and process related intrinsic sources. Witness plates are proposed as a comprehensive strategy for the real time detection of visible particles, sources of extrinsic and intrinsic visible particles, and methods to identify particle types. Implementing the control measures described herein, which include air ionization units for the control and neutralization of static charges, would maximize device yield and quality, thus reducing rework and leading to increased profitability. Installing validated air ionization systems at appropriate manufacturing and processing locations, storage, product transfer areas, and gown-up rooms can significantly reduce visible particle contamination accumulation, dispersion, and yield losses. Implementing effective material transfer practices can further minimize the risk of introduction of unwanted particles and particle dispersion within classified areas. Also described are additional control measures, such as material systems and supply chain controls, good facility design, gowning practices, manufacturing equipment and tool controls, and manual visual inspections which would further contribute to the overall reduction of particle burden. Crucial elements of an effective particle removal process are the dry and wet cleaning processes and the facility surveillance program. Process-product-particle traceability matrices can serve as effective tools to promptly identify trends and reduce device conformity defects. For this paper, the meaning of the term particle only includes particulates and particulate matter. Microbial contamination control approaches, including facility decontamination, are outside the scope of this paper.
{"title":"Strategies for the Control of Visible Particles in Sterile Devices","authors":"Dilip Ashtekar","doi":"10.17764/1557-2196-64.1.1","DOIUrl":"https://doi.org/10.17764/1557-2196-64.1.1","url":null,"abstract":"\u0000 Currently, limited guidance is available for the contamination control of visible particles for the manufacture of sterile devices; thus, a comprehensive guidance is warranted. Sterile devices require stringent control of visible particulates to ensure proper functionality, performance assurance of sterility, reliability, patient safety, efficacy, and product quality. This paper outlines practical and science-based strategies to prevent/minimize visible particle contamination from non-process related extrinsic and process related intrinsic sources. Witness plates are proposed as a comprehensive strategy for the real time detection of visible particles, sources of extrinsic and intrinsic visible particles, and methods to identify particle types. Implementing the control measures described herein, which include air ionization units for the control and neutralization of static charges, would maximize device yield and quality, thus reducing rework and leading to increased profitability. Installing validated air ionization systems at appropriate manufacturing and processing locations, storage, product transfer areas, and gown-up rooms can significantly reduce visible particle contamination accumulation, dispersion, and yield losses. Implementing effective material transfer practices can further minimize the risk of introduction of unwanted particles and particle dispersion within classified areas. Also described are additional control measures, such as material systems and supply chain controls, good facility design, gowning practices, manufacturing equipment and tool controls, and manual visual inspections which would further contribute to the overall reduction of particle burden. Crucial elements of an effective particle removal process are the dry and wet cleaning processes and the facility surveillance program. Process-product-particle traceability matrices can serve as effective tools to promptly identify trends and reduce device conformity defects. For this paper, the meaning of the term particle only includes particulates and particulate matter. Microbial contamination control approaches, including facility decontamination, are outside the scope of this paper.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45487555","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: 10.17764/1557-2196-64.1.57
D. Ensor, R. Mielke, Jennifer Sklena
International Organization for Standardization (ISO) Technical Committee (TC) 209’s first meeting was held in November 1993.The focus was on cleanrooms and controlled environments and the activities within cleanrooms. The TC has moved in recent years to generic operations documents such as a systematic approach for procuring disposables and particle deposition rate monitoring to improve the quality of products manufactured in a cleanroom. ISO stresses development of standards with requirements to support sustainability. A recently published standard on energy management in a cleanroom supports that need. ISO has a range of publication formats with different rigor in balloting to reduce document development being considered by the TC. ISO/TC 209 begins its third decade taking a more integrated approach to standardization with the goal of responding to the needs of industry.
{"title":"Update of ISO Technical Committee 209 Cleanrooms and Associated Controlled Environments","authors":"D. Ensor, R. Mielke, Jennifer Sklena","doi":"10.17764/1557-2196-64.1.57","DOIUrl":"https://doi.org/10.17764/1557-2196-64.1.57","url":null,"abstract":"\u0000 International Organization for Standardization (ISO) Technical Committee (TC) 209’s first meeting was held in November 1993.The focus was on cleanrooms and controlled environments and the activities within cleanrooms. The TC has moved in recent years to generic operations documents such as a systematic approach for procuring disposables and particle deposition rate monitoring to improve the quality of products manufactured in a cleanroom. ISO stresses development of standards with requirements to support sustainability. A recently published standard on energy management in a cleanroom supports that need. ISO has a range of publication formats with different rigor in balloting to reduce document development being considered by the TC. ISO/TC 209 begins its third decade taking a more integrated approach to standardization with the goal of responding to the needs of industry.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43010855","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 : 2020-12-01DOI: 10.17764/1557-2196-63.1.21
A. Steinwolf
The fatigue damage spectrum (FDS) model characterizes how the damage potential is distributed over the excitation frequency range, similarly to how the power spectral density (PSD) characterizes the distribution of the excitation level. However, reproducing the operational PSD during in-house shaker testing does not necessarily mean that the FDS would be also reproduced because some unusually distinctive peaks, higher than those in a signal generated from the PSD, occur in vibrations of automobiles and railway vehicles. Presence of these peaks in real operational vibrations and their absence in the PSD-based random testing is the reason why the shaker testing FDS obtained by the ordinary PSD control is different in shape and usually lies below the operational FDS. It is shown in this paper that the FDS shape as a function of frequency can be controlled by manipulating some of the IFFT phases instead of making all of them random. Since the phase manipulation does not affect the excitation PSD, the FDS and the PSD can be controlled simultaneously, which is demonstrated for an example of operational vibrations of an automobile. This new concept of shaker testing with the PSD+FDS control can also be used for accelerated testing when the FDS target needs to be artificially increased. It can be done without scaling up the PSD, thereby avoiding concerns about the test exaggeration factor being too high.
{"title":"Shaker Testing with Simultaneous Control of PSD and FDS","authors":"A. Steinwolf","doi":"10.17764/1557-2196-63.1.21","DOIUrl":"https://doi.org/10.17764/1557-2196-63.1.21","url":null,"abstract":"\u0000 The fatigue damage spectrum (FDS) model characterizes how the damage potential is distributed over the excitation frequency range, similarly to how the power spectral density (PSD) characterizes the distribution of the excitation level. However, reproducing the operational PSD during in-house shaker testing does not necessarily mean that the FDS would be also reproduced because some unusually distinctive peaks, higher than those in a signal generated from the PSD, occur in vibrations of automobiles and railway vehicles. Presence of these peaks in real operational vibrations and their absence in the PSD-based random testing is the reason why the shaker testing FDS obtained by the ordinary PSD control is different in shape and usually lies below the operational FDS. It is shown in this paper that the FDS shape as a function of frequency can be controlled by manipulating some of the IFFT phases instead of making all of them random. Since the phase manipulation does not affect the excitation PSD, the FDS and the PSD can be controlled simultaneously, which is demonstrated for an example of operational vibrations of an automobile. This new concept of shaker testing with the PSD+FDS control can also be used for accelerated testing when the FDS target needs to be artificially increased. It can be done without scaling up the PSD, thereby avoiding concerns about the test exaggeration factor being too high.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43194490","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 : 2020-12-01DOI: 10.17764/1557-2196-63.1.75
M. Appolloni, S. Fransen, H. Fischer, M. Remedia
The HYDRA facility is a very large 6-Degrees-of-Freedom (DoF) hydraulic shaker located in the European Space Research and Technology Centre of ESA in The Netherlands. It has been recently used as test platform to perform a number of innovative, 6-DoF experimental vibration runs with the aim of assessing more flight-representative ways to dynamically qualify a spacecraft, hence reducing the level of conservatism. This paper focuses on the methodology behind the definition of the injected profiles computed by launcher/spacecraft coupled loads analysis, the performance achieved by HYDRA and its state-of-the-art MIMO control system, how the experimental data compare to the simulation ones, and aims also at defining success criteria for 6-DoF transient testing.
{"title":"TRANSIENT MULTI-DOF VIBRATION TESTING: ANALYTICAL AND EXPERIMENTAL DATA","authors":"M. Appolloni, S. Fransen, H. Fischer, M. Remedia","doi":"10.17764/1557-2196-63.1.75","DOIUrl":"https://doi.org/10.17764/1557-2196-63.1.75","url":null,"abstract":"\u0000 The HYDRA facility is a very large 6-Degrees-of-Freedom (DoF) hydraulic shaker located in the European Space Research and Technology Centre of ESA in The Netherlands. It has been recently used as test platform to perform a number of innovative, 6-DoF experimental vibration runs with the aim of assessing more flight-representative ways to dynamically qualify a spacecraft, hence reducing the level of conservatism. This paper focuses on the methodology behind the definition of the injected profiles computed by launcher/spacecraft coupled loads analysis, the performance achieved by HYDRA and its state-of-the-art MIMO control system, how the experimental data compare to the simulation ones, and aims also at defining success criteria for 6-DoF transient testing.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45798934","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 : 2020-12-01DOI: 10.17764/1557-2196-63.1.
D. Gibbons
The ISO 14644 family of cleanroom standards has been at the center of international cleanroom standards development for many years and covers most facets of cleanroom activity and cleanroom types from large ballroom cleanrooms to isolators and clean tunnels. The series is under constant review and is still expanding. Recent documents that have been released concern the quantification of airborne and surface chemical concentrations, nanoparticles and the selection and testing of equipment used within these rooms. However, apart from some misleading information in the original Part 4 design document, questions concerning the energy demands from air purification processing have been overlooked. Nationally, institutions such as the BSI in UK, DIN- VDI in Germany and IEST in the USA have produced limited information on the topic, but Part 16 is the first standard to be internationally agreed upon. The key new features of the standard are a) the preparation of an accurate User Requirement Specification (URS), b) a practical method for estimating the volume of supply air needed to maintain the specified ISO room classifications in operation, c) tuning and d) benchmarking. An informative annex develops three useful metrics for benchmarking: power intensity for contamination removal (PICR), fan energy intensity for contamination removal (EICR) and energy intensity (EI).
ISO 14644系列洁净室标准多年来一直处于国际洁净室标准发展的中心，涵盖了洁净室活动和洁净室类型的大多数方面，从大型舞厅洁净室到隔离室和洁净隧道。该系列正在不断地进行审查，并仍在扩大。最近发布的文件涉及空气和表面化学物质浓度的量化，纳米粒子以及这些房间内使用的设备的选择和测试。然而，除了最初的第4部分设计文件中的一些误导性信息外，有关空气净化处理的能源需求的问题被忽视了。在全国范围内，英国的BSI、德国的DIN- VDI和美国的est等机构已经就该主题提供了有限的信息，但第16部分是第一个国际商定的标准。该标准的主要新特点是:a)准备了准确的用户要求规范(URS); b)一种实用的方法来估计维持指定ISO房间分类运行所需的送风量;c)调整和d)基准测试。一份信息丰富的附件开发了三个有用的基准指标:污染去除功率强度(PICR)，污染去除风扇能量强度(EICR)和能量强度(EI)。
{"title":"Energy efficiency in cleanrooms and separative devices: ISO 14644-16, outreach article","authors":"D. Gibbons","doi":"10.17764/1557-2196-63.1.","DOIUrl":"https://doi.org/10.17764/1557-2196-63.1.","url":null,"abstract":"\u0000 The ISO 14644 family of cleanroom standards has been at the center of international cleanroom standards development for many years and covers most facets of cleanroom activity and cleanroom types from large ballroom cleanrooms to isolators and clean tunnels. The series is under constant review and is still expanding.\u0000 Recent documents that have been released concern the quantification of airborne and surface chemical concentrations, nanoparticles and the selection and testing of equipment used within these rooms. However, apart from some misleading information in the original Part 4 design document, questions concerning the energy demands from air purification processing have been overlooked. Nationally, institutions such as the BSI in UK, DIN- VDI in Germany and IEST in the USA have produced limited information on the topic, but Part 16 is the first standard to be internationally agreed upon.\u0000 The key new features of the standard are a) the preparation of an accurate User Requirement Specification (URS), b) a practical method for estimating the volume of supply air needed to maintain the specified ISO room classifications in operation, c) tuning and d) benchmarking. An informative annex develops three useful metrics for benchmarking: power intensity for contamination removal (PICR), fan energy intensity for contamination removal (EICR) and energy intensity (EI).","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42182062","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 : 2020-12-01DOI: 10.17764/1557-2196-63.1.13
Elaine E. Seasly, Walter Wrigglesworth
Throughout the assembly, integration, and test process, molecular contamination levels of space mission hardware are monitored to meet system performance requirements. Qualitatively, reflective surfaces and witness mirrors are continuously inspected for the visible presence of molecular contaminant films. Quantitatively, periodic reflectance measurements of witness mirrors indicate changes of mirror reflectivity over time due to the accumulation of molecular contaminant films. However, both methods only consider the presence of a contaminant film and not the molecular composition. Additionally, there is a risk that hardware may appear to be “visibly clean” even with a molecular contaminant film present on critical surfaces. To address these issues, experiments were performed to quantify the maximum molecular contaminant film that could be missed in visual inspections on witness mirrors with five different contaminants present. The corresponding changes in mirror reflectivity were modeled using the program STACK to determine the impact to space mission hardware performance. The results of this study not only show the criticality in considering the chemical make-up of molecular contaminant films on system performance, but also the need to recognize and understand the limitations of traditional visual inspection techniques on detecting molecular contaminant films.
{"title":"Blind to Chemistry: Molecular Contaminant Films We Could Be Missing During Visual Inspections and the Potential Impact to System Performance","authors":"Elaine E. Seasly, Walter Wrigglesworth","doi":"10.17764/1557-2196-63.1.13","DOIUrl":"https://doi.org/10.17764/1557-2196-63.1.13","url":null,"abstract":"\u0000 Throughout the assembly, integration, and test process, molecular contamination levels of space mission hardware are monitored to meet system performance requirements. Qualitatively, reflective surfaces and witness mirrors are continuously inspected for the visible presence of molecular contaminant films. Quantitatively, periodic reflectance measurements of witness mirrors indicate changes of mirror reflectivity over time due to the accumulation of molecular contaminant films. However, both methods only consider the presence of a contaminant film and not the molecular composition. Additionally, there is a risk that hardware may appear to be “visibly clean” even with a molecular contaminant film present on critical surfaces. To address these issues, experiments were performed to quantify the maximum molecular contaminant film that could be missed in visual inspections on witness mirrors with five different contaminants present. The corresponding changes in mirror reflectivity were modeled using the program STACK to determine the impact to space mission hardware performance. The results of this study not only show the criticality in considering the chemical make-up of molecular contaminant films on system performance, but also the need to recognize and understand the limitations of traditional visual inspection techniques on detecting molecular contaminant films.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45765837","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 : 2020-12-01DOI: 10.17764/1557-2196-63.1.35
Ariel Fabricio Scagliotti, G. A. Jorge
Low-cost sensors for relative humidity, pressure, and ambient temperature have begun to be used regularly for different applications in which the measurement or control of systems or processes is required using an affordable technology. However, in most cases, reliable information about their performance, capabilities, and limitations is not available. In this work, we aim to establish a systematic comparison between different sensors widely used in conjunction with the Arduino platform, such as the DS18b20, DHT11, BMP180, and BME280 sensors. Laboratory and field trials were performed to determine linearity, accuracy, precision, resolution, response times, and response to loss of power. The results indicate that these devices, despite having a very low cost, can provide relatively reliable information, taking into account their manufacturing characteristics and the specific use required. In turn, this work offers useful information to choose the sensor that best suits a particular project.
{"title":"Inter-comparison of environmental low-cost sensors on Arduino platform","authors":"Ariel Fabricio Scagliotti, G. A. Jorge","doi":"10.17764/1557-2196-63.1.35","DOIUrl":"https://doi.org/10.17764/1557-2196-63.1.35","url":null,"abstract":"\u0000 Low-cost sensors for relative humidity, pressure, and ambient temperature have begun to be used regularly for different applications in which the measurement or control of systems or processes is required using an affordable technology. However, in most cases, reliable information about their performance, capabilities, and limitations is not available. In this work, we aim to establish a systematic comparison between different sensors widely used in conjunction with the Arduino platform, such as the DS18b20, DHT11, BMP180, and BME280 sensors. Laboratory and field trials were performed to determine linearity, accuracy, precision, resolution, response times, and response to loss of power. The results indicate that these devices, despite having a very low cost, can provide relatively reliable information, taking into account their manufacturing characteristics and the specific use required. In turn, this work offers useful information to choose the sensor that best suits a particular project.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43382047","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 : 2020-01-01DOI: 10.17764/1557-2196-63.1.1
B. Thaveau, J. Vanhee
The installed filter system leak test method for cleanrooms and clean zones is described in ISO 14644-3, Cleanrooms and associated controlled environments—Part 3: Test method. Portions of the methods in ISO 14644-3 were adapted from IEST-RP-CC034.4[Schaumburg, Illinois, US: Institute of Environmental Science and Technology], which provides a set of recommended procedures for leak testing HEPA and ULPA filters in situ (in the field) with the aerosol photometer test method and the light scattering airborne particle counter (LSAPC) test method. Leak testing is performed to confirm that the final high efficiency air filter system is properly installed by verifying the absence of bypass leakage in the installation, and that the filters are free of defects (small holes and other damage in the filter medium, frame, seal and leaks in the filter bank framework). This study was conducted to compare the aerosol photometer and LSAPC methods. Testing in the study consisted of creating artificial leaks in the filter system, measuring the upstream and downstream concentrations with the aerosol photometer and with the LSAPC, and comparing the filter leak penetration results. Comparison testing was applied to the procedure for the installed terminal panel filter system leakage scan test (stationary measurement) and the procedure for evaluating overall leakage of high-airflow box-type filters mounted in a duct or air-handling unit (AHU) (overall leakage test). It was found that the aerosol photometer and the LSAPC gave similar results for filter leakage within experimental error. The comparison of the leakage scan tests (stationary measurement) showed that the penetration calculated for the channel ≥ 0.3 μm of the LSAPC with an air flow rate of 1cu ft/min (CFM) (28.3 l/min) was very similar to the penetration measured with the aerosol photometer for a leakage level >0.01 % of the upstream concentration. The comparison result of the overall leakage test showed that overall total penetration values, obtained after dilution of artificial calibrated leaks in the filter media, were identical, within the measurement uncertainty, for particles ≥0.3 μm whether the sampling rate of the LSAPC was 1 CFM (28.3 l/min) or 50 l/min. Several recommendations are provided. In particular, for filters mounted in a duct or AHU where the filter function is critical, the recommended method is the leakage scan test method, using a grid sampling method in a plane downstream of the filter (as agreed between customer and supplier).
{"title":"Comparison of the Aerosol Photometer and Light Scattering Airborne Particle Counter (LSAPC) Methods for Installed Filter System Leak Testing","authors":"B. Thaveau, J. Vanhee","doi":"10.17764/1557-2196-63.1.1","DOIUrl":"https://doi.org/10.17764/1557-2196-63.1.1","url":null,"abstract":"The installed filter system leak test method for cleanrooms and clean zones is described in ISO 14644-3, Cleanrooms and associated controlled environments—Part 3: Test method. Portions of the methods in ISO 14644-3 were adapted from IEST-RP-CC034.4[Schaumburg, Illinois, US: Institute of Environmental Science and Technology], which provides a set of recommended procedures for leak testing HEPA and ULPA filters in situ (in the field) with the aerosol photometer test method and the light scattering airborne particle counter (LSAPC) test method. Leak testing is performed to confirm that the final high efficiency air filter system is properly installed by verifying the absence of bypass leakage in the installation, and that the filters are free of defects (small holes and other damage in the filter medium, frame, seal and leaks in the filter bank framework). This study was conducted to compare the aerosol photometer and LSAPC methods. Testing in the study consisted of creating artificial leaks in the filter system, measuring the upstream and downstream concentrations with the aerosol photometer and with the LSAPC, and comparing the filter leak penetration results. Comparison testing was applied to the procedure for the installed terminal panel filter system leakage scan test (stationary measurement) and the procedure for evaluating overall leakage of high-airflow box-type filters mounted in a duct or air-handling unit (AHU) (overall leakage test). It was found that the aerosol photometer and the LSAPC gave similar results for filter leakage within experimental error. The comparison of the leakage scan tests (stationary measurement) showed that the penetration calculated for the channel ≥ 0.3 μm of the LSAPC with an air flow rate of 1cu ft/min (CFM) (28.3 l/min) was very similar to the penetration measured with the aerosol photometer for a leakage level >0.01 % of the upstream concentration. The comparison result of the overall leakage test showed that overall total penetration values, obtained after dilution of artificial calibrated leaks in the filter media, were identical, within the measurement uncertainty, for particles ≥0.3 μm whether the sampling rate of the LSAPC was 1 CFM (28.3 l/min) or 50 l/min. Several recommendations are provided. In particular, for filters mounted in a duct or AHU where the filter function is critical, the recommended method is the leakage scan test method, using a grid sampling method in a plane downstream of the filter (as agreed between customer and supplier).","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67782593","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 : 2020-01-01DOI: 10.17764/1557-2196-63.1.46
Jin Wang
With the progress of building materials and building technology, the span of bridges is becoming larger and larger. This paper briefly introduces the incremental launching construction technology of a bridge and the incremental launching construction technology of pontoon fulcrum conversion, makes an instance analysis on a large-span steel arch bridge that adopted the incremental launching technology of pontoon fulcrum conversion in Shaoyang, Hunan, China, and makes a simulation calculation on the construction process using Midas civil software. The construction process was monitored using stress sensors and total station. The results showed that the simulation results of the stress and deformation changes of the steel arch bridge in the construction process were close to the actual monitoring data, and the variation trend was basically the same. The finite element model effectively simulated the stress and deformation changes of the steel arch bridge in incremental launching. With the progress of construction conditions, the maximum stress and deformation degree of the arch rib increased first and then decreased, the maximum stress and deformation degree of the main longitudinal beam showed an increase tendency, the maximum stress of the front guide beam increased first and then decreased, and the deformation degree gradually decreased.
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