定价： 1274元 / 折扣价： 1083 元

1.1 PurposeThe purpose of this guide is to define good commercial and customary practice in the United States of America for conducting a baseline survey for readily observable mold and conditions conducive to mold in a commercial building related to a commercial real estate transaction by conducting: a walk-through survey, document reviews, and interviews as outlined within this guide. This guide is intended to identify observable mold and physical deficiencies conducive to mold as a result of moisture and water infiltration through the commercial buildings envelope or substructure, or generated within the building as a result of processes or mechanical systems, excluding de minimis observable mold and physical deficiencies conducive to mold. This guide is to allow a user to assess the potential need for further assessment or other actions that may be appropriate that are beyond the scope of this guide. For purposes of this guide, the acronym "BSP" or "Baseline Survey Process" is used interchangeably with this guides full title.1.2 Purpose LimitationsWhile a BSP may be used to survey for readily identifiable mold and physical deficiencies conducive to mold, the BSP is not designed to serve as comprehensive survey for the presence of observable mold and physical deficiencies conducive to mold in all or most areas in a commercial building. It is not intended to reduce the risk of the presence of observable mold and physical deficiencies conducive to mold nor is it to eliminate the risk that observable mold and physical deficiencies conducive to mold may pose to the building or its occupants.1.3 Considerations Beyond This The use of this guide is strictly limited to the scope set forth in this section. Section of this guide identifies, for informational purposes, certain physical conditions (not an all-inclusive list) that may exist at a property and certain activities or procedures (not an all-inclusive list) that are beyond the scope of this guide but may warrant consideration by parties to a commercial real estate transaction. The need to investigate any such conditions in the consultants scope of services should be evaluated based upon, among other factors, the nature of the property and the reason for conducting the BSP. The scope of such further investigation or testing services should be agreed upon between the user and the consultant as additional services, which are beyond the scope of this guide, prior to initiation of the BSP process. The responsibility to initiate work beyond the scope of this guide lies with the user.1.3.1 Sampling for mold growth is a non-scope consideration under this guide. As noted by EPA 402-K-01-001, sampling cannot be used to assess whether a commercial building complies with federal standards, since no EPA or other federal standards or Threshold Limit Values (TLVs) have been established for mold spores. And, sampling would only produce results reflecting a specific moment in time in the best case and could produce inaccurate or misleading results in the worst case.1.4 Organization of the GuideThis guide has 13 sections and three appendices. Section defines the . Section is Referenced Documents. Section is Terminology. Section defines the Significance and Use of this guide. Section describes User Responsibilities. Sections through provide guidelines for the main body of the report, including the scope of the Walk-through Survey and preparation of the report. Section and identifying Out of Considerations. Section lists keywords for Internet reference. provides the user with additional BSP scope considerations, whereby a user may increase this guides baseline scope of due diligence to be exercised by the consultant, provides the user with a suggested Interview Checklist, and provides the user with a suggested Field Checklist.

定价： 0元 / 折扣价： 0 元

定价： 592元 / 折扣价： 504 元

定价： 592元 / 折扣价： 504 元

4.1 Use—This guide is intended for use on a voluntary basis by parties who wish to obtain a limited survey of commercial real estate to assess for readily observable moisture affected materials and physical deficiencies conducive to elevated moisture as part of a commercial real estate transaction or commercial property management. This guide is intended to constitute a limited inquiry using representative observations for the purposes of conducting due diligence regarding the actual and potential presence of readily observable moisture affected materials and physical deficiencies conducive to elevated moisture in connection with the subject property. Inquiries that are more and less comprehensive than this guide (including, in some instances, no inquiry) may be appropriate in some circumstances in the opinion of the user (for example, when the presence of moisture affected materials is known to the user). Furthermore, no implication is intended that a person must use this guide in order to be deemed to have conducted appropriate inquiry in a commercially prudent or reasonable manner in a particular transaction. Nevertheless, this guide is intended to reflect a commercially prudent and reasonable inquiry. However, a LMA is not intended to serve as a comprehensive survey for the presence of readily observable moisture affected materials and physical deficiencies conducive to elevated moisture in all or most of the building systems throughout a commercial building.4.2 Clarification of Use: 4.2.1 Specific Point in Time—Because conditions conducive to elevated moisture in a building can vary greatly over time due to changes in weather, interior air handling and conditioning, occupancy, and so forth, a user should only rely on the results presented in the report for the point in time at which the LMA was conducted.4.2.2 Site-Specific—This guide is site-specific in that it relates to assessment of readily observable moisture affected materials and physical deficiencies conducive to elevated moisture within a specific commercial building. Consequently, this guide does not address many additional issues raised in commercial real estate transactions such as purchases of business entities, or interests therein, or of their assets, that may well involve liabilities pertaining to properties previously owned or operated or other on-site or off-site liabilities.4.2.3 Residential Tenants/Purchasers and Others—No implication is intended that it is currently customary practice for residential tenants of multifamily residential buildings, or other residential real estate to conduct a LMA in connection with these transactions. Thus, these transactions are not included in the term commercial real estate transaction, and it is not intended to imply that such persons are obligated to conduct a LMA in connection with these transactions for purposes of appropriate inquiry or for other purposes.4.3 Who May Conduct—The walk-through survey portion of a LMA should be conducted by a field observer qualified as outlined in Section 7.4.4 Additional Services—As set forth in 11.13, additional services may be contracted for between the user and the provider. Such additional services may include moisture metering, sampling of suspect fungal growth, invasive testing, thermographic imaging, environmental site assessments, property condition assessments or other services not included within the scope of this guide, examples of which area identified in Section 12 under Out of Considerations.4.5 Principles—The following principles are an integral part of this guide and are intended to be referred to in resolving ambiguity or exercising such discretion as is accorded the user or provider in conducting a LMA or in judging whether a user or provider has conducted appropriate inquiry or has otherwise conducted an adequate LMA.4.5.1 Uncertainty Not Eliminated—No limited survey of readily observable moisture affected materials and physical deficiencies conducive to elevated moisture can wholly eliminate uncertainty regarding the potential for readily observable moisture affected materials and physical deficiencies conducive to elevated moisture to be present at the subject property. Performance of a LMA pursuant to this guide is intended to reduce, but not eliminate, uncertainty regarding the current readily observable moisture affected materials and physical deficiencies conducive to elevated moisture at a property nor to eliminate the potential for readily observable moisture affected materials and physical deficiencies conducive to elevated moisture to be or to become present. The guide recognizes a provider’s findings may be determined under time constraints, formed without the aid of testing, exploratory probing, the removal of materials, design, or other technically exhaustive means.4.5.2 Not Exhaustive—Appropriate inquiry does not mean an exhaustive assessment of the subject property. There is a point at which the cost of information obtained or the time required to gather it outweighs the usefulness of the information and, in fact, may be a material detriment to the orderly completion of transactions. One of the purposes of this guide is to identify a balance between the competing goals of limiting the costs and time demands inherent in performing a LMA and the reduction of uncertainty about unknown conditions resulting from additional information.4.5.3 Activity Exclusions—Certain activities are generally excluded from or otherwise represent limitations to the scope of a LMA prepared in accordance with this guide. These should not be construed as all-inclusive or implying that any exclusion not specifically identified is a LMA requirement under this guide. Specifically excluded activities include:4.5.3.1 Removing or relocating materials, furniture, storage containers, personal effects, debris materials or finishes; conducting exploratory probing or testing; dismantling or operating equipment or appliances; or disturbing personal items or property which obstructs access or visibility.4.5.3.2 Sampling of any type, including sampling for suspect fungi or other forms of biological growth, or sampling or otherwise measuring moisture or other physical characteristics.4.5.3.3 Entering or accessing areas of the premises deemed to pose a threat of dangerous or adverse conditions with respect to the field observer or to perform any procedure that may damage or impair the physical integrity of the subject property, any building system, or component.4.5.3.4 Providing an environmental site assessment, property condition assessment, or any element of an environmental site assessment or property condition assessment.4.5.4 Hidden Areas—Moisture affected materials may occur in hidden areas such as: within wall cavities, within crawlspaces; above ceiling tiles or beneath flooring materials, and so forth. Possible locations of hidden moisture affected materials can include pipe chases and utility tunnels, porous thermal or acoustic liners inside ductwork, or roof insulation materials above roof decks of ceilings. If the user suspects the presence of hidden moisture affected materials (for example, due to musty smells), the user should communicate this fact to the provider. If the provider suspects the presence of hidden moisture affected materials, the provider should detail such findings in the report. Further investigation of hidden moisture affected materials is beyond the scope of work described in this guide.4.5.5 Representative Observations—The purpose of conducting representative observations is to convey to the user the expected magnitude of commonly encountered or anticipated conditions. Representative observation quantities should be provided in the agreement between user and provider; however, if in the provider’s opinion such representative observations as presented in the agreement are unwarranted as a result of homogeneity of the asset or other reasons deemed appropriate by the provider, a sufficient number of units, areas, systems, buildings, and so forth may be observed so as to achieve a reasonable confidence as to the representative present conditions of such repetitive or similar areas, systems, buildings, and so forth.4.5.5.1 User-Requested Representative Observations—A user may define the representative observations required for a given subject property.4.5.5.2 Extrapolation of Findings—Provider may reasonably extrapolate representative observations and findings to all typical areas or systems of the subject property for the purposes of describing such conditions within the report. The provider’s rationale for the extrapolation of findings should be included in the report.4.5.6 Level of Inquiry Is Variable—Not every commercial real estate transaction will warrant the same level of assessment. Consistent with good commercial practice, the appropriate level of survey will be guided by the type of property subject to assessment, the expertise and risk tolerance of the user, geographic and other environmentally related issues such as local climate, drainage and proximity to surface water, and other information that may be developed during the course of the LMA.4.5.7 Comparison With Subsequent Inquiry—It should not be concluded or assumed that an inquiry was not an appropriate inquiry merely because the inquiry did not identify readily observable moisture affected materials and physical deficiencies conducive to elevated moisture in connection with a commercial building. LMAs should be evaluated based on the reasonableness of judgments made at the time and under the circumstances in which they were made. Subsequent LMAs should not be considered valid standards to judge the appropriateness of any prior assessment based upon hindsight, changed conditions, new information, use of developing technology or analytical techniques, or other factors.4.6 Rules of Engagement—The contractual and legal obligations between a provider and a user (and other parties, if any) are outside the scope of this guide. No specific legal relationship between the provider and the user is necessary for the user to meet the requirements of this guide.1.1 Purpose—The purpose of this guide2 is to define good commercial practice for conducting a limited survey for readily observable moisture affected materials and conditions conducive to elevated moisture in a commercial building related to commercial real estate transaction or commercial real estate management by conducting: a walk-through survey, document reviews, and interviews as outlined within this guide. This guide is intended to provide a practical means for the limited identification of moisture affected materials and physical deficiencies conducive to elevated moisture caused by water infiltration through the building envelope or substructure or generated within the subject building as a result of processes or mechanical systems, excluding de minimis conditions. This guide is to allow a user to assess general moisture concerns, as well as the potential need for further assessment or other actions that may be appropriate that are beyond the scope of this guide. For purposes of this guide, the initialism “LMA” or “Limited Moisture Assessment” is used interchangeably with this guide’s full title.1.2 Purpose Limitations—While a LMA may be used to survey for readily identifiable moisture affected materials and physical deficiencies conducive to elevated moisture, the LMA is not designed to serve as comprehensive survey for the presence of moisture affected materials and physical deficiencies conducive to elevated moisture in all or most areas in a commercial building. It is not intended to reduce or eliminate the risks that elevated moisture may pose to the subject building or its occupants.1.3 Considerations Beyond This —The use of this guide is limited to the scope set forth in this section. Section 12 of this guide identifies, for informational purposes, certain physical conditions (not an all-inclusive list) that may exist at a subject property and certain activities or procedures (not an all-inclusive list) that are beyond the scope of this guide but may warrant consideration by users. The need to investigate any such conditions in the provider’s scope of services should be evaluated based upon, among other factors, the nature of the subject property and the reason for conducting the LMA. The scope of such further investigation or testing services should be agreed upon between the user and the provider as additional services, which are beyond the scope of this guide, prior to initiation of the LMA process. The responsibility to initiate work beyond the scope of this guide lies with the user.1.3.1 Sampling for suspect fungi and other forms of biological growth is a non-scope consideration under this guide.1.3.2 Sampling or otherwise measuring for moisture is a non-scope consideration under this guide.1.4 Organization of the Guide—This guide has 13 sections and two appendices. Section 1 defines the . Section 2 is Referenced Documents. Section 3 is Terminology. Section 4 defines the of this guide. Section 5 describes User Responsibilities. Sections 6 through 11 provide guidelines for the main body of the report, including the scope of the walk-through survey and preparation of the report. Section 12 identifies Out of Considerations. Section 13 lists keywords for Internet reference. Appendix X1 provides the user with a suggested Interview Checklist, and Appendix X2 provides the user with a suggested Field Checklist.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 843元 / 折扣价： 717 元 加购物车

5.1 Internal—The EMPM provides assessment results that are easy to understand and communicate. Areas requiring additional resources become apparent, and thus, can be more readily addressed. Improvement can be tracked in meaningful ways. Assessment detail allows attention to be drawn to processes of exceptional maturity and areas in which changes or additional resources, or both, are required to achieve process improvements.5.2 External—Meaningful comparisons to external requirements are enabled. Comparisons of equipment management between entities in different operational or business environments become meaningful and provide insight previously unavailable.1.1 This practice covers a process for the assessment and reporting of an entity’s overall equipment management process maturity (EMPM).1.2 The highest value is placed on continuous improvement as reflected in measured increases in maturity over time.1.3 The EMPM model is designed to be applicable and appropriate for all equipment-holding entities, however, the EMPM may not be the only acceptable assessment model available.1.4 It includes all aspects of equipment management.1.5 In addition to applicability to equipment and equipment management as defined in this practice, this practice may in whole or in part be effectively applied to intangible property, real property, and material.1.6 There is great variation across organizations regarding the internal departments that accomplish the various aspects of equipment management. Thus, all criteria are not applicable to all entities.1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 Uses:  4.1.1 This practice is intended for use on a voluntary basis by parties who wish to evaluate known releases or likely release areas identified by the user or Phase II Assessor, and/or to assess the presence or likely presence of substances, for legal or business reasons such as those described in 1.2. 4.1.2 This practice is intended to meet the business community's need for a written, practical reference describing a scientifically sound approach to investigating a property to evaluate the presence or likely presence of a substance. It is impossible to generalize about the contexts in which a user may wish to conduct such investigations or the degree of confidence a user may require in the results. In any context, this practice, being rooted in sound scientific methodology, can assist users in achieving an objective and defensible assessment. 4.1.2.1 This practice does not address the evaluation of business environmental risks in light of data collected through the Phase II ESA process. Such evaluation is a function of site- and transaction-specific variables, and of the user’s objectives and risk tolerance. This practice contemplates that the Phase II ESA process will be planned and conducted with such variables in mind, and that the user will evaluate legal, business and environmental risks in light of known data relating to the particular site and transaction, and in consultation with legal and business advisors as well as the Phase II Assessor. 4.1.2.2 Likewise, this practice does not define the threshold levels at which target analytes pose a concern of significance to the user. Users may apply this practice not only in light of applicable regulatory criteria and relevant liability principles, but also to meet self-defined objectives. 4.1.2.3 If a Phase II ESA conducted in accordance with this practice provides sufficient information from which the Phase II Assessor can conclude, consistent with the scientific method, that the question to be addressed by the assessment (see 6.4.1) has been answered, then further assessment is not warranted to meet the objectives of the assessment. 4.1.3 Use Not Limited to CERCLA—This practice is designed to assist a user in developing information about the environmental condition of the property and has utility for a wide range of target analytes (e.g., including diffuse anthropogenic contamination and naturally occurring substances) and users including those who may have no actual or potential CERCLA concerns. 4.1.4 Site- and Transaction-Specific—The scope of a Phase II ESA is site-specific and context-specific. The assessment process defined by this practice is intended to generate sound, objective, and defensible information sufficient to satisfy diverse user objectives. 4.1.5 Use by Other Parties—This practice does not define whether or to what extent any person other than the user may use or rely upon a Phase II ESA prepared for the user. The appropriateness of third party use or reliance is a contractual matter that should be addressed between user and Phase II Assessor, see Appendix X2, section X2.4. 4.2 Principles—The following principles are an integral part of this practice and are intended to be referred to in resolving any ambiguity or exercising such discretion as is accorded the user or Phase II Assessor. 4.2.1 Elimination of Uncertainty—No Phase II ESA can eliminate all uncertainty. Furthermore, any sample, either surface or subsurface, taken for chemical testing may or may not be representative of a larger population. Professional judgment and interpretation are inherent in the process, and even when exercised in accordance with objective scientific principles, uncertainty is inevitable. Additional assessment beyond that which was reasonably undertaken may reduce the uncertainty. 4.2.1.1 Failure to Detect—Even when Phase II ESA work is executed competently and in accordance with this practice, it must be recognized that certain conditions present especially difficult target analyte detection problems. Such conditions may include, but are not limited to, complex geological settings, unusual or generally poorly understood behavior and fate characteristics of certain substances, complex, discontinuous, random, dynamic, or spotty distributions of existing target analytes, physical impediments to investigation imposed by the location of utilities and other man-made objects, and the inherent limitations of assessment technologies. 4.2.1.2 Limitations of Information—The effectiveness of a Phase II ESA may be compromised by limitations or defects in the information used to define the objectives and scope of the investigation, including inability to obtain information concerning historical site uses or prior site assessment activities despite the efforts of the user and Phase II Assessor to obtain such information in accordance with 5.1.3. 4.2.1.3 Chemical Analysis Error—Chemical testing methods have inherent uncertainties and limitations. The Phase II Assessor shall build quality control and quality assurance measures into the assessment, as outlined in Section 7. The Phase II Assessor should require the laboratory to report any potential or actual problems experienced, or nonroutine events which may have occurred during the testing, so that such problems can be considered in evaluating the data. The Phase II Assessor should subsequently identify such problems in any reports or documentation provided to the user. Any laboratory utilized for chemical testing shall be accredited in accordance with applicable state requirements. 4.2.2 Level of Assessment—Phase II ESAs do not generally require an exhaustive assessment of environmental conditions on a property. There is a point at which the cost of information obtained and the time required to obtain it outweigh the benefit of the information and, in the context of private transactions and contractual responsibilities, may become a material detriment to the orderly conduct of business. If the presence of target analytes is confirmed on a property, the extent of further assessment is a function of the degree of confidence required and the degree of uncertainty acceptable, in relation to the objectives of the assessment. 4.2.3 Comparison With Subsequent Inquiry—The justification and adequacy of the findings of a Phase II ESA in light of the findings of a subsequent inquiry should be evaluated based on the reasonableness of judgments made at the time and under the circumstances in which they were made. 4.2.4 Data Usability—Investigation data generally only represent the site conditions at the time the data were generated and site conditions can be dynamic. Therefore, the usability of data collected as part of a Phase II ESA may have a finite lifetime depending on the application and use being made of the data. To the extent that investigation data would fall within the scope of data used in a Phase I ESA conducted pursuant to Practice E1527 or Practice E2247, the lifetime limits defined by those standards apply. In all other respects, a Phase II Assessor should evaluate whether previously generated data are appropriate for any subsequent use beyond the original purpose for which they were collected, or are otherwise subject to lifetime limits imposed by other laws, regulations or regulatory policies. 4.2.5 Phase II Assessor Does Not Provide Legal or Business Advice—The Phase II ESA is intended to develop and present sound, scientifically valid data concerning actual site conditions. It shall not be the role of the Phase II Assessor to provide legal or business advice. 1.1 This practice2 covers a process for conducting a Phase II environmental site assessment (ESA) of a parcel of property with respect to the presence or the likely presence of substances including but not limited to those within the scope of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) (e.g., hazardous substances), pollutants, contaminants, petroleum and petroleum products, and controlled substances and constituents thereof. It specifies procedures based on the scientific method to characterize property conditions in an objective, representative, reproducible, and defensible manner. To promote clarity in defining Phase II ESA objectives and transparency in communicating and interpreting Phase II ESA results, this practice specifies adherence to requirements for documenting the scope of assessment and constraints on the conduct of the assessment process. 1.1.1 A user's interest in the presence or likely presence of substances in environmental media at a property may arise in a wide variety of legal, regulatory, and commercial contexts, and may involve diverse objectives including those listed in 1.2. This practice contemplates that the user and the Phase II Assessor will consult to define the scope and objectives of investigation in light of relevant factors, including without limitation the substances released or possibly released at the property, the nature of the concerns presented by their presence or likely presence, the behavior , fate and transport characteristics of substances released or possibly released, the portion of the property to be investigated, the information already available, the degree of confidence needed or desired in the results, the degree of investigatory sampling and chemical testing needed to achieve such confidence, and any applicable time and resource constraints. This practice requires that Phase II activities be conducted so that the resulting scope of work is performed, and the stated objectives are achieved, in a scientifically sound manner. 1.1.2 A Phase II ESA in accordance with this practice may be conducted after site assessment activities in accordance with Practice E1527 for Phase I Environmental Site Assessments: Phase I Environmental Site Assessment Process, Practice E2247 for Environmental Site Assessments: Phase I Environmental Site Assessment for Forestland or Rural Property, EPA’s All Appropriate Inquiries (AAI) Rule, 40 C.F.R. Part 312, or Practice E1528 for Limited Environmental Due Diligence: Transaction Screen Process. In defining the scope and purposes of a Phase II ESA, however, previous decisions to classify property conditions or areas as RECs, or to refrain from doing so, are not determinative as to whether investigation of the same conditions or areas is appropriate to meet the objectives of the Phase II ESA. 1.2 Objectives—This practice is intended for use where a user desires to obtain sound, scientifically valid data concerning actual property conditions, whether or not such data relate to property conditions previously identified as RECs or data gaps in Phase I ESAs. Without attempting to define all such situations, this practice contemplates that users may seek such data to inform their evaluations, conclusions, and choices of action in connection with objectives that may include, without limitation, one or more of the following: 1.2.1 Objective 1—Assess whether there has been a release of hazardous substances within the meaning of CERCLA, for purposes including landowner liability protections (i.e., innocent landowner, bona fide prospective purchaser, and contiguous property owner). 1.2.2 Objective 2—Provide information relevant to identifying, defining or implementing landowner “continuing obligations,” or the criteria established under CERCLA (e.g., exercising appropriate care by taking reasonable steps to prevent or limit exposures to previously released hazardous substances) for maintaining the CERCLA landowner liability protections. 1.2.3 Objective 3—Develop threshold knowledge of the presence of substances on properties within the scope of the CERCLA definition of a “brownfield site” and as required for qualifying for brownfields remediation grants from the EPA Brownfields Program. 1.2.4 Objective 4—Provide information relevant to identifying, defining and evaluating property conditions associated with target analytes that may pose risk to human health or the environment, or risk of bodily injury to persons on the property and thereby give rise to potential liability in tort. 1.2.5 Objective 5—Provide information relevant to evaluating and allocating business environmental risk in transactional and contractual contexts, including transferring, financing and insuring properties, and due diligence relating thereto. 1.2.6 Objective 6—Provide information to support disclosure of liabilities and contingent liabilities in financial statements and securities reporting. 1.2.7 Additional information concerning these six objectives may be found in the Legal Appendix, Appendix X1. 1.3  of Assessment in Relation to Objectives—The scope of a Phase II ESA is related to the objectives of the investigation. Both scope and objectives may require ongoing evaluation and refinement as the assessment progresses. 1.3.1 In developing the scope of work and in evaluating data and information concerning the property, the Phase II Assessor must determine whether the available information is sufficient to meet the objectives of the investigation. Even after conducting Phase II activities to generate additional data, the Phase II Assessor must independently evaluate the sufficiency of the data in relation to the objectives. As the investigation progresses, the objectives may be refined or redefined in consultation between the user and the Phase II Assessor. 1.3.2 A single round of sampling and chemical testing may not always provide data sufficient to meet the chosen objectives. If not, this practice contemplates additional sampling in an iterative sequence that concludes when the available data are sufficient. This practice also acknowledges, however, that the user may instead elect either to redefine the objectives so that they can be met with the data available, or to terminate the investigative process without meeting the stated objectives. The Phase II Assessment report must disclose any respect in which available data are insufficient to meet objectives. 1.3.3 This practice does not require full site characterization in every instance, but may be used to carry out an investigation sufficient for that purpose if desired to meet the user's objectives. 1.4 Needs of the User—The user and Phase II Assessor must have a mutual understanding of the context in which the Phase II ESA is to be performed and the objectives to be met by the investigation, i.e. the specific questions to be answered or problems to be resolved by the Phase II ESA. The scope of Phase II activities must be defined in relation to those objectives. 1.4.1 The degree of confidence desired by the user influences the scope of the investigation and the evaluation of data. More extensive testing and more iterations of sampling and analysis may be needed if the objectives require detailed conclusions with high confidence. Less testing and fewer iterations of sampling and analysis may be needed if the objectives of the assessment require only general conclusions. 1.5 Limitations—This practice is not intended to supersede applicable requirements imposed by regulatory authorities. This practice does not attempt to define a legal standard of care either for the performance of professional services with respect to matters within its scope, or for the performance of any individual Phase II ESA. 1.6 Organization of This Practice—This practice has nine sections and four appendices. Section 1 covers the of the practice. Section 2, Referenced Documents, lists ASTM and other organizations’ related standards and guidance that may be useful in conducting Phase II ESAs in accordance with this practice. Section 3, Terminology, contains definitions of terms and acronyms used in this practice. Section 4 addresses the of this practice, including the legal context into which Phase II ESAs may fall. Section 5 discusses development and documentation of the scope of the Phase II ESA, including the Statement of Objectives for the assessment. Section 6 provides a Phase II ESA Overview, with purpose and goal descriptions. Section 7 comprises the main body of Performing the Phase II ESA, and includes initiating scientific inquiry by formulating the question to be answered (7.1), collecting and evaluating information (7.2), identifying areas for investigation (7.3), developing the conceptual model (7.4), developing a plan and rationale for sampling (7.5), conducting the sampling (7.6), and validating the conceptual model (7.7). Interpretation of results is covered in Section 8. Phase II Environmental Site Assessment report preparation is addressed in Section 9. Appendix X1 supports Section 4, and contains legal considerations pertaining to Phase II Environmental Site Assessment. Appendix X2 contains contracting considerations between Phase II assessor and user. Appendix X3 supports Section 9, and describes two examples and a sample table of contents illustrating possible approaches to reporting the results of a Phase II Environmental Site Assessment. Appendix X4 supplements Section 2 with a list of standards and references that may be relevant in conducting a Phase II Environmental Site Assessment. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 843元 / 折扣价： 717 元 加购物车

This specification covers steel plates produced by the thermo-mechanical control process (TMCP). The plates are intended primarily for use in welded pressure vessels. The steel shall be killed and shall conform to specified fine austenitic grain size and chemical composition requirements. If the plates are to be subjected to warm forming or post-weld heat treatment, the test coupons shall be subjected to heat treatment to simulate such fabrication operations. The tension test and notch toughness test requirements are presented in details. Two tension tests shall be made from each plate-as-rolled. One test coupon shall be taken from a corner of the plate on each end.1.1 This specification2 covers steel plates produced by the thermo-mechanical control process (TMCP). The plates are intended primarily for use in welded pressure vessels. A description of the TMCP method is given in Appendix X1.1.2 Due to the inherent characteristics of the TMCP method, the plates cannot be formed at elevated temperatures without sustaining significant losses in strength and toughness. Except for Grade G, the plates may be formed and post-weld heat-treated at temperatures not exceeding 1200°F [650°C], providing the requirements of 6.1 are met. Grade G plates may be formed at temperatures not exceeding 985°F [530°C] provided the requirements of 6.1 are met.1.3 The maximum permitted nominal thickness of plates furnished to this specification is 4 in. [100 mm] for Grades A, B, and C; 1.5 in. [40 mm] for Grades D,3 E, and F; and 2 in. [50 mm] for Grade G.1.4 Grade G is susceptible to magnetization. Use of magnets in handling after heat treatment should be avoided if residual magnetism would be detrimental to subsequent fabrication or service.1.5 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents. Therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

定价： 683元 / 折扣价： 581 元

This specification covers 9% nickel-alloy steel plates produced by the direct-quenching process. The plates are intended primarily for use in welded pressure vessels. The steel shall be killed and shall conform to the fine austenitic grain size requirement specified. The steel shall conform to the chemical requirements specified. Tension test and impact test shall be made to conform to the requirements specified.1.1 This specification covers 9 % nickel-alloy steel plates produced by the direct-quenching process. The plates are intended primarily for use in welded pressure vessels.1.2 The direct-quenching process consists of quenching the plates directly after rolling, without permitting the plates to cool below the critical temperature prior to initiation of the quenching operation, and subsequently tempering the plates (see Appendix X1). (Note: The direct-quenching process differs from the “conventional” process in which the plates are permitted to cool to a temperature significantly below the critical temperature, usually to ambient temperature, prior to reheating to a temperature above the upper critical temperature, then quenching, and subsequently tempering.)1.3 If the plates are subjected to warm forming, the temperature shall not exceed 950°F [510°C].1.4 The maximum nominal thickness of plates furnished under this specification shall not exceed 2 in. [50 mm].1.5 This material is susceptible to magnetization. Use of magnets in handling after heat treatment should be avoided if residual magnetism would be detrimental to subsequent fabrication or service.1.6 The values stated in either inch-pound or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

定价： 683元 / 折扣价： 581 元

4.1 This practice will provide the following: (1) a statistical summary of individual production run data plotted on a control chart; (2) a statistical summary of data from multiple production runs; (3) a procedure to relate the average and variation of these data groups to specification limits, and (4) indexes for comparing different manufacturing units for projecting future capabilities or as historical reference.1.1 This practice covers (1) a statistical procedure for analyzing the test data generated in the statistical process control of a carbon black manufacturing process; (2) a format for reporting process capability determined from the analysis of control chart data of an individual production run, and (3) a format for reporting process performance determined from the analysis of control chart data of an individual production run.1.2 This practice specifically applies to the analysis of pelleted carbon black samples taken during the manufacturing process prior to storage. This practice does not apply to shipment samples taken from hopper cars or other containers or packages.1.3 This practice is specifically designed to be used for those test methods given in Classification D1765 which specify target values. However, these techniques are applicable to other test methods on carbon black.1.4 This practice describes the calculation for two methods of determining capability factors from an analysis of process control data.1.4.1 Process capability (Cp) is a measurement of variation calculated from the process control chart data with the use of an estimated standard deviation (^σ) from the mean value of the moving range (R) chart. The calculation of the process capability (Cp and Cpk) indexes can be used as historical information or to predict future performance of the process, but are only valid when the process is in a state of statistical control.1.4.2 Process performance (Pp) is a measurement of variation calculated from the process control chart data using sample standard deviation(s). The calculation of the process performance (Pp and Ppk) indexes are used for a historical reference of a process' performance and does not require a state of statistical control.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

The objectives of the respiration inhibition tests may be defined by the interests of the user, but the test method is designed primarily for examination of the inhibition response with operating microbial systems such as an activated sludge process treating domestic or industrial wastes. Different apparatus exist that facilitate continuous or continual measurement of respiration in microbial systems and each may be used as the tool to observe respiration in this test method. Respirometry may utilize any apparatus and technique that will achieve the determination of respiration rate. A number of devices are presented in Appendix X1. Equivalency in the experimental capability of each device is not implied. The analyst should select the respirometric approach that best suits his needs. The inhibitory effect of a test candidate is identified more completely by examining inhibition over a range of concentrations, such as determining the EC50. The use of aerated containers permits concurrent management of a series of cell suspensions. A respirometer for each cell suspension might also be used.1.1 This test method covers a batch procedure that evaluates the impact of selected wastewaters, materials, or specific compounds on the respiration rate of an aqueous microbial culture, such as activated sludge. 1.2 Alternative procedures for measurement of microbial activity, such as adenosine 5′ triphosphate (ATP), specific substrate utilization, etc. are not within the scope of this test method. 1.3 The results obtained are based on comparisons in a specific test series that examines a range of concentrations of the potentially inhibitory test candidate using batch methods in a laboratory. Results are completed in a short time frame (a few hours). 1.4 The test results are specific to the microbial culture used. Microbial culture from different wastewater treatment plants will differ in kinds and numbers of organisms, and performance capability. Thus, there is no basis for comparing results for microbial cultures from different treatment facilities. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元

This practice covers pharmaceutical process design utilizing process analytical technology, which is integral to process development as well as post-development process optimization. It is focused on practical implementation and experimental development of process understanding. The principles in this practice are applicable to both drug substance and drug product processes. For drug products, formulation development and process development are interrelated and therefore the process design will incorporate knowledge from the formulation development. The following practices and methodologies shall be done to attain desired state: risk assessment and mitigation; continuous improvement; process fitness for purpose; intrinsic performance assessment; manufacturing strategy; data collection and formal experimental design; multivariate tools; process analyzers; and process control.1.1 This practice covers process design, which is integral to process development as well as post-development process optimization. It is focused on practical implementation and experimental development of process understanding.1.2 The term process design as used in this practice can mean:1.2.1 The activities to design a process (the process design), or1.2.2 The outcome of this activity (the designed process), or both.1.3 The principles in this practice are applicable to both drug substance and drug product processes. For drug products, formulation development and process development are interrelated and therefore the process design will incorporate knowledge from the formulation development.1.4 The principles in this practice apply during development of a new process or the improvement or redesign of an existing one, or both.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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4.1 Metal additive manufacturing has broadened design space, enabling production of more complex and customized products. Additive technology along with the broadened design space is pushing the limits of inspection capabilities and has led to challenges in process and product qualification, verification, certification, etc. In-process monitoring technologies have been developed to help address these challenges.4.2 In-process monitoring in AM is emerging from the realm of Research and Development (R&D). As such, there are not yet well-established procedures for incorporating AM process monitoring within a qualification or certification framework outside of a specific company or institution’s internal use. Practical application of in-process monitoring data spans multiple disciplines and parts of the production cycle, each with well-established practices, terminology, expectations, etc. This guide draws on these where appropriate.4.3 Inspection and Statistical Process Control (SPC)—A primary motivation for using in-process monitoring technologies is to aid in process and product qualification, verification, certification of AM components that are increasingly difficult to inspect. AM process monitoring functions can be broadly separated into two categories of application: in-process inspection and process control. In-process inspection refers to the identification of in-process signatures that correlate to the formation of physical flaws and defects in additively manufactured component. This is discussed further in 5.2 on Flaw Detection. Statistical Process Control (SPC) encompasses measurement or observation of process signatures or metrics associated with the stability or repeatability of the additive manufacturing process. This is discussed further in 5.3 on Statistical Process Control (SPC). Real-time feed-forward or feed-back control methods and techniques may be considered subcategories under process control, and can make use of the same in-process monitoring measurement tools. Currently, these concepts and techniques are still largely under research and development not generally implemented in commercial LPBF systems. They are not discussed further in this guide.4.4 Production and Development Uses—Production of finished components using additive manufacturing requires some combination of inspection to ensure the component meets design requirements for the ultimate product functionality and process qualification. Both inspection and process control applications of in-process monitoring may be integrated into an overall product or process qualification, verification, or certification strategy, or a combination thereof, in the production environment. In-process monitoring tools are also valuable in the development both of the additive process and build design, providing support for engineering decisions on parameter selection (for example, laser power, scan speed) for new materials, scan strategy, part geometry, part placement on an AM build platform, etc. A prerequisite to SPC is establishing the normal variation of the process which can be evaluated using in-process monitoring tools during process development.4.5 Economic Justification—In-process monitoring can be economically justified through its contribution to cost reduction and yield improvements in addition to its value to the additive manufacturing enterprise as an element of an overall process or product qualification, verification, or certification strategy, or a combination thereof. For high value products, in-process monitoring has been shown to reduce the scrap fraction rate by at least 10 % according to recent literature.7 The realization of the cost/part reduction in the scrap fraction rate over time is dependent on the diagnostic capability of the in-process monitoring strategy as measured in false alarm (false positive) and undetected defect (false negative) performance. Further in-process monitoring can produce per part cumulative yield improvements through enabling process engineering diagnosis capabilities within part manufacturing such that SPC charts can be tuned to optimize the system’s diagnostic performance.4.6 Identifying Part Quality from Process Signatures—Ultimately, final part quality metrics and associated mechanical or functional performance of AM parts are of greatest concern. Guide E3166, pertaining to ex-situ NDT, identifies two correlations of interest: process-flaw correlation and flaw-property correlation. In the context of this guide, measurements of material flaws or properties are considered part quality metrics. As noted in Guide E3166, part quality metrics may be correlated to the process or process parameters, such as laser power, laser scan speed, etc. as shown in Fig. 1. In-process monitoring pertains to the observation and measurement of process signatures, or observable phenomena that occur during the AM process, for example, electromagnetic emissions from the melt pool, acoustic emissions, etc. Process signatures are correlated to process parameters. While process parameters are generally commanded or set point values, process signatures provide a measured voice of process. Process signatures may also be correlated to part quality metrics, as shown in Fig. 1. As part of a product inspection and validation strategy, in-process monitoring aims to utilize the correlation between these process signatures and part quality metrics. In-process monitoring can thus be used to in conjunction with or in-lieu of post-process inspection methods (for example, NDE).FIG. 1 General Schematic of AM In-process Monitoring High-level Objectives for Inspection to Identify the Correlations, Through Analytical or Numerical Methods, that Relate Process Signatures to Part Quality Metrics and Utilize These as Part of a Broader Inspection or Part Validation Strategy4.6.1 Process Signature Taxonomy—Many different terms have been used in AM to describe process signatures or part quality metrics in the context of in-process monitoring (for example, defect, fault, flaw, anomaly, imperfection, etc.). The following provides a high-level taxonomy used in this guide to further define and categorize deleterious process signatures in AM process monitoring. As noted in 4.3, in-process monitoring is primarily used as part of an overall quality plan, either as a supplement to or replacement of traditional component inspection methods (for example, NDE) or to enable statistical process control. These two functions are mapped to corresponding taxonomies are mapped in Fig. 2.FIG. 2 Description of Higher-level Terms Relating an Observation of Process Signatures From In-process Monitoring for Inspection and Statistical Process Control (SPC) use Cases4.6.2 For the in-process enabled inspection case, this taxonomy builds upon established standards or work items (see Terminology E1316, Guide E3166, and ISO/ASTM TR 52905).(1) Indication (Terminology E1316): In an in-process enabled inspection, a process signature observed from the in-process monitoring data that is evidence of a potential material flaw is deemed an indication (Terminology E1316). As in traditional NDE, the indication is subject to interpretation as a false indication, nonrelevant indication, or relevant indication (Terminology E1316). A relevant indication (Terminology E1316) is indicative of a material flaw and requires further evaluation as to whether the flaw is acceptable or the part must be rejected based on the requirements of the component.(2) Flaw (Terminology E1316): A flaw is an imperfection or discontinuity, the formation of which may be detectible by in-process monitoring, but is not necessarily rejectable.(3) Defect (Terminology E1316): One or more flaws whose aggregate size, shape, orientation, location, or properties do not meet specified acceptance criteria and are rejectable.4.6.3 Statistical process control (SPC) uses statistical methods to improve quality by reducing the variability of one or more process outputs. For in-process monitoring enabled statistical process control, one or more process signatures are the outputs of the process to which SPC is applied. Process variation may be classified in one of two categories, common cause variation or special cause variation.(1) Common Cause Variation (Practice E2587), also referred to as chance variation, is inherent random variation in the process which is predictable within statistical limits. An additive manufacturing process may be said to be in a state of statistical control when only common cause variation is observed (Practice E2587).(2) Special Cause Variation (Practice E2587), also referred to as assignable cause variation, associated with a process disturbance or upset. Special cause variation may be associated with a spike, shift, trend, or change in variability of the in-process signal.4.7 Additive Manufacturing Flaws and Flaw Formation Mechanisms—Understanding how in-process flaws and defects form during fabrication is critical to the instrument design, data analysis or interpretation, and general application of AM in-process-monitoring. The following describe flaws that may exhibit in-process, and may be targeted for observation by in-process monitoring instruments. The following is not a comprehensive list or categorization of in-process flaws or defects, but is meant as a guide to better understand how the most commonly observed or understood flaws and defects may relate to in-process monitoring. Additional details regarding in-process defect and flaw formation are provided in regards to each measurement system modality discussed starting in Section 7.4.7.1 Stochastic versus Systemic Defect Formation—Systematic defects are voids resulting from input processing parameters and build plan. In contrast, stochastic flaws result from conditions that are not systematically controlled (that is, are a consequence of random or statistical processes), as shown in Fig. 3.FIG. 3 Example Organization and Categorization of Some Flaws Observable in a Laser Powder Bed Fusion (LPBF) Process, Categorized by 'Systematic' or 'Stochastic' FormationNOTE 1: Reprinted from Additive Manufacturing, Vol 36, Snow, Z., Nassar, A. R., and Reutzel, E. W., “Review of the formation and impact of flaws in powder bed fusion additive manufacturing,” 2020, 101457, https://doi.org/10.1016/j.addma.2020.101457, with permission from Elsevier.4.7.2 In-process Defects: 4.7.2.1 Void Formation—The term voids (voids in Guide E3166, or synonymous with discontinuity in Terminology E1316) includes any material discontinuity within a part that is not a designed feature. This includes pores and cracks. While the methods of formation of voids is not always discernible in post-process inspection, their formation and corresponding signatures may be observable and distinguishable via in-process monitoring.(1) Pores (Guide E3166)—Pores are material discontinuities that are distinguishable from cracks, but may similarly act as stress concentration or crack initiation sites. Cracks, viewed in 2D, are a discontinuity with an extremely low aspect-ratios. Pores and cracks may be surface-connected. In the context of this guide, pores are further sub-categorized from description in Guide E3166 based on their formation mechanisms and potential signatures:(a) Keyhole Porosity (Guide E3166 and ISO/ASTM TR 52905)—Keyhole porosity is related to instability in the liquid melt pool, and typically occurs under relatively high laser energy density (7.2.2). Observation of keyhole porosity generally requires melt pool monitoring to capture a keyhole event, or related melt pool signature (7.2.2). This can be generally (but not directly) related to observation of a deeper, wider, or brighter melt pool. Individual keyhole pores are roughly an order of magnitude smaller than the melt pool, or approximately the scale of typical LPBF powder (for example, 10’s of μm). Specific instrument design criteria, and statistical correlation between in-process monitoring observations and keyhole pore formation are still a matter of research and development.(b) Gas Porosity (Guide E3166)—Gas porosity, thought to result from gas entrapped within a powder particle during manufacturing of the powder or interstitial gases released due to reduced solubility upon solidification, is generally not considered to be observable via current in-process monitoring techniques, since the pores are incorporated into the powder material and do not typically reach the surface.(2) Lack of Fusion (LOF) (Guide E3166 and ISO/ASTM TR 52905)—LOF pore formation can be subcategorized as either horizontal LOF or vertical LOF (ISO/ASTM TR 52905). Generally, only horizontal LOF pores or events are observable on the top surface of the fabricated layer via in-process monitoring. However, observation of multiple LOF events within the same region over multiple layers may be indicative of formation of vertical LOF pores.(3) Hatching LOF—A horizontal LOF stemming from incomplete melting and wetting of adjacent scan tracks.(4) Hatch-contour Overlap and Short-hatch Flaw—A horizontal LOF stemming from incomplete melting and wetting at the intersection of a contour and infill laser scan tracks.4.7.2.2 Cracking: (1) Delamination Cracking—Delamination occurs when layers within an AM build separate from one another forming a cavity or crack, often due to excessive residual stress buildup during fabrication in conjunction with poor design of the part or support materials, or both, or selection of appropriate AM build parameters. This most often occurs at the interface between a solid part structure and support structure, support and substrate, or the solid part and substrate. During AM fabrication, delamination cracking may be observed as increasing elevation of the part above new powder surface, or acoustic signatures that occur during cracking events.(2) Solidification Cracking (or Hot Cracking) —Solidification-cracking occurs when rapid cooling at the fusion boundary of a melt pool causes high thermal strain and separation of material that is not adequately filled by molten material. Solidification cracks may occur during solidification, or very shortly after, and can be enlarged or exacerbated by subsequent heating and cooling cycles. Certain materials are more susceptible to hot cracking than others, and various filler materials may be introduced to the alloy to reduce susceptibility. Combination of process parameters, and their effect on melt pool shape and resultant thermal gradients in and around the melt pool, can contribute to the likelihood of solidification cracking. Solidification cracks may be observable via acoustic signatures, but are generally too small and occur for indication via optical means.4.7.3 In-process Flaws: 4.7.3.1 Overheating, Overmelting, or Thermal Heterogeneity—Due to the dynamically moving heat sources used during AM processing, some regions of a fabricated part can experience excessive heat accumulation and elevated temperatures relative to the rest of the part volume. This can generally be attributed to one or two factors: (1) combination of scan-strategy and layer geometry which causes excessive laser exposure over a confined area within the layer (Fig. 4); (2) laser exposure over a confined region, where the relatively low thermal conductivity of the surrounding powder inhibits conduction of heat away from the melt pool. Local overheating can be observed via several process signatures: (1) Increased size, temperature, or brightness of a melt pool (see 7.2.5 on Melt pool ‘intensity’); (2) discoloration or ‘scorching’ of the overheated region, and (3) humping, elevation, abnormally smooth/fluid, or generally different surface structure and topography in the overheated region (see Section 8 on Layer Imaging).FIG. 4 Example From Staring-configuration, Near-infrared (NIR) Spectrum Melt Pool Monitoring Camera. This System Compiles Images from Multiple Camera Exposures and Processes Them Into a Single Image. Left: Image Data Based on ‘Integrated’ Values, Which Highlight Thermal Heterogeneity Features. Right: Image Data Based on ‘Maximum’ Value, Which Highlight Spatter or Plume FeaturesNOTE 1: Barfoot, M. (2020). Evaluation of In-Situ Monitoring Techniques (Additive Manufacturing Consortium (AMC) Project Final Report, EWI Project No. 58279CPQ).(1) Excessive Spatter/Ejecta—At the LPBF melt pool scale, many particles can be observed escaping (or ejected) from the vicinity of the melt. These particles initiate from several phenomena. Melt ejection occurs when evaporation-induced recoil pressure exceeds the surface tension pressure within the melt pool, causing molten droplets to escape. Spatter particles also result from powder particle entrainment within the evaporation-induced gas flow. Hot spatter particles are formed due to laser- or vapor-induced heating of entrained particles. Relatively frequent, intense, or excessive hot spatter may be targeted by process monitoring instruments (Fig. 4) as an indication of flaw or defect formation, or deleterious fabrication quality.4.7.3.2 Powder Layer or Recoating Flaws—Improper application of metal powder layers during LPBF fabrication can result in part defects. A number of in-process flaws associated with insufficient or improper powder layer formation are known, and are generally easily observed and interpreted. Generally, the source of these flaws can be categorized as stemming from the erroneous recoating process (for example, skipping, scraping, insufficient powder delivery, part strikes), part formation errors (distortion, humping, balling, or superelevation). While many of these flaws may be observable through multiple process monitoring modalities, they are primarily observed through Layer Imaging processes. Refer to Section 8 on Layer Imaging for detailed description of powder layer flaws.4.7.4 Speed, Resolution, and Data Considerations—Speed, resolution, and data considerations specific to each sensor modality will be discussed starting in Section 7. Generally, data rate and storage requirements for process monitoring are relatively high, which largely stems from the multi-scale physics of the AM fabrication process, and the necessity to adequately resolve signatures spatially or temporally.4.7.4.1 For example, assume a typical 250 mm x 250 mm build area, divided into 0.1 mm x 0.1 mm pixels (25002 pixels/layer). Assume a 200 mm build height divided into 0.02 mm layers (10 000 layers/build). This results in 25002 pixels/layer × 10 000 layers/build × 1 byte/pixel = 62.5 GB/build. Similarly, in the temporal domain, consider a sensor acquiring data at 100 kHz, over a 36 h build. This results in a 105 samples/s × 129 600 s/build × 1 bytes/sample results in approximately 13 GB/build. These values are only given as typical examples, but indicate the relative volume of data that might be expected to be on the order of 10’s of GB per sensor per build.4.7.5 Data Reduction or Compression—Most often, in-process monitoring data size is reduced either in-line during acquisition, or just prior to storage, so that the raw instrument values are not transferred or stored. This is done by processing the data into a reduced-dimension parameter (for example, obtaining a single-value measurand from a 2D image), reducing the indicated or represented resolution (for example, averaging or ‘binning’ pixels in an image), removing unnecessary data (for example, dark or saturated pixels in an image), employing data compression algorithms (lossy or loss-less), or employing other data reduction methods.4.7.6 Data Alignment or Registration—Data alignment, registration, and visualization considerations specific to each sensor modality will be discussed in Sections 7 – 9. Refer to subcommittee ASTM F42.08 for proposed standards on data alignment and registration.4.7.6.1 Visualization of in-process monitoring data is typically represented in the spatial domain, such that sensor signals or process signatures derived from those signals are mapped to the spatial position within the 3D part when or where, or both, they were acquired (Fig. 5). Most often, this is represented in three ways: (1) 3D part representation, where signatures or features are mapped to the 3D location within a part, forming digital representation of the part(s), but constructed from process monitoring data; (2) 2D layer representation, where the data is mapped to a plane nominally commensurate with an AM fabrication layer (normal to the build direction); or (3) 2D slice representation, where values or data from a 3D part representation are projected onto a planar slice that is oriented in a direction different than the 2D layer representation.FIG. 5 Example Registration of 1D Process Monitoring Data (Signal versus Time from Melt Pool Monitoring (MPM) Photodetectors in Co-axial Configuration) into 3D Representation, Which Can Then be Projected onto Different Planar Slices (a) 2D Layer Representation (XY Plane), (b) 2D Slice Representation (YZ Plane), (c) 2D Slice Representation (XZ Plane), (d) 3D Part Representation (Orthographic Projection), Showing Location of the 2D Slice Locations4.7.6.2 In this manner, the geometric location of those process signatures that may indicate an in-process flaw or defect can potentially be aligned and correlated to the same flaw or defect observed via ex-situ methods (for example, X-ray computed tomography (XCT)). For example, see Fig. 6.FIG. 6 Example Local Anomaly Observed in Co-axial Configuration, Photodetector-based Melt Pool Monitoring (Left), and Corresponding Observation of a Pore Defect (Right) from XCT of the Fabricated PartNOTE 1: Barfoot, M. (2020). Evaluation of In-Situ Monitoring Techniques (Additive Manufacturing Consortium (AMC) Project Final Report, EWI Project No. 58279CPQ).4.7.6.3 Alignment of in-process measured process signatures with part geometry requires additional measurements to obtain information that relates the positioning of the sensor’s field of view or sensing area to a coordinate system shared by the machine or parts. For further description of some of the measurement references, refer to ASTM subcommittee F42.08 for proposed standards on data alignment and registration. Some examples of accessory measurements for data alignment or registration are as follows:(1) Simultaneous Acquisition of Laser/Galvo Position versus Time—Many commercial process monitoring systems enable synchronized acquisition of the laser scan position via the galvanometer (galvo) system in parallel with the process monitoring instruments. This is done either by reading the digital commands (for example, XY2-100 or SL2-100 digital command protocol) sent to the galvanometer, or reading galvo feedback encoder signal, if available. Alignment or registration of process monitoring instrument signals or images is done by directly mapping the sensor signal to the synchronized spatial location (for example, XY position) where it was obtained from the galvo position. This method is widely used for co-axial instrument configurations (for example, melt pool monitoring, Section 7), or single-element detectors that do not provide spatial information (for example, staring configuration photodetector or mounted acoustic sensor).(2) Reference Scan Pattern—Particularly for staring configuration instruments in a LPBF system, a reference pattern or grid with known geometry can be scanned on a bare substrate, initial layers within a build, or during intermediate layers within a build. Measurement via the process monitoring sensors may be conducted synchronously with the scan, or immediately after completion. Dimensions of the reference pattern may be known from the commanded reference pattern geometry programmed into the AM machine controller, or via ex-situ measurement by a calibrated dimensional measurement (for example, calipers, optical CMM). Signal or images acquired from the process monitoring instruments may then be mapped or transformed into the coordinates acquired via the measured reference scan pattern.(3) Reference Target—Similar to the scanned reference pattern, a calibrated dimensional target or artifact may be placed in the field of view or sensing area of the process monitoring instrument(s). For example, an imager may observe a dimensional calibration artifact that has been oriented with the machine or part coordinate system (Section 8). An additional step may be necessary to reference the position of the artifact with respect to the machine or part coordinates.4.8 AM Process Monitoring Modalities—In the context of this guide, modality describes a group of similar process monitoring technologies, grouped based on similar attributes regarding the measured object(s) or phenomena of interest, or the types of measurement instruments employed. In-depth discussion of different modalities are discussed beginning in Section 7. Different modalities may be sub-categorized or grouped in different ways. An additional important descriptor for process monitoring techniques is the physical configuration of the sensor(s).4.8.1 Physical Configurations—Process monitoring sensors of various types can be fixed to stationary locations onto or within the AM machine. The same type of sensor can be fixed into different configurations, which will change the position, field of view, or coordinate frame in which the sensor data is defined. The two primary configurations used in LPBF in-process monitoring, staring configuration, and co-axial configuration, are shown in Fig. 7.FIG. 7 Example Schematic of Two Common Instrument Physical Configurations in Laser Powder Bed Fusion (LPBF) Process Monitoring: (a) Co-axial Configuration and (b) Staring Configuration4.8.1.1 Staring Configuration,also known as ‘offline’ or ‘fixed position’ configuration. This is a non-contact configuration where the sensor is placed in a fixed position with respect to the build plane or machine coordinate system (see ISO/ASTM 52921). A staring configuration sensor can be fixed either inside or outside the controlled-environment (build) chamber. This configuration is typical with single-point pyrometer, camera or thermal imager, etc.4.8.1.2 Co-axial Configuration,also known as ‘on-axis’ or ‘inline’. This is a non-contact configuration especially suited for optical or radiometric sensors, where the sensor is mounted in an optical path shared by the laser heat source. The field of view of the sensor is then fixed to the moving reference frame of the laser spot and moves in the same scan trajectories of the laser throughout the fabrication process. This effectively keeps the melt pool stationary within the sensor field of view. Example sensors include filtered radiometers, spectrometers, or high-speed cameras.4.8.1.3 Other Configurations—A variety of other physical instrument configurations can exist that may be unique, specialized, or not easily described by the aforementioned configurations. For example, an acoustic microphone may be suspended within the build chamber, or an oxygen sensor set within the inert gas recirculation system (for example, machine condition monitoring, Section 9).1.1 This guide provides information on emerging in-process monitoring sensors, sensor configurations, sensor data analysis, and sensor data uses for the laser powder bed fusion additive manufacturing process.1.2 The sensors covered produce data related to and affected by feedstock, processing parameters, build atmosphere, microstructure, part geometry, part complexity, surface finish, and the printing equipment being used.1.3 The parts monitored by the sensors covered in this guide are used in aerospace applications; therefore, their final inspection requirements for discontinuities are different and more stringent than for materials and components used in non-aerospace applications.1.4 The metal materials under consideration include, but are not limited to, aluminum alloys, titanium alloys, nickel-based alloys, cobalt-chromium alloys, and stainless steels.1.5 This guide discusses sensor observation of parts while they are being fabricated. Sensor data analysis may take place concurrently or after the manufacturing process has concluded.1.6 The sensors discussed in this guide may be used by cognizant engineering organizations to detect both surface and volumetric flaws.1.7 The sensors discussed in this guide may be used by cognizant engineering organizations to detect process stability or drift, or both.1.8 The sensors discussed in this guide are primarily configured in staring, co-axial, or mounted configurations.1.9 This guide does not recommend a specific course of action, sensor type, or configuration for application of in-process monitoring to additively manufactured (AM) parts. It is intended to increase the awareness of emerging in-process sensors, sensor configurations, data analysis, and data usage.1.10 Recommendations about the control of input materials, process equipment calibration, manufacturing processes, and post-processing are beyond the scope of this guide and are under the jurisdiction of ASTM Committee F42 on Additive Manufacturing Technologies. Standards under the jurisdiction of ASTM F42 or equivalent are followed whenever possible to ensure reproducible parts suitable for NDT are made.1.11 Recommendations about the inspection requirements and management of fracture critical AM parts are beyond the scope of this guide. Recommendations on fatigue, fracture mechanics, and fracture control are found in appropriate end user requirements documents, and in standards under the jurisdiction of ASTM Committee E08 on Fatigue and Fracture.NOTE 1: To determine the deformation and fatigue properties of metal parts made by additive manufacturing using destructive tests, consult Guide F3122.NOTE 2: To quantify the risks associated with fracture critical AM parts, it is incumbent upon the structural assessment community, such as ASTM Committee E08 on Fatigue and Fracture, to define critical initial flaw sizes (CIFS) for the part to define the objectives of the NDT.1.12 This guide does not specify accept-reject criteria used in procurement or as a means for approval of AM parts for service. Any accept-reject criteria are given solely for purposes of illustration and comparison.1.13 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.14 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.15 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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