定价： 774元 / 折扣价： 658 元

定价： 590元 / 折扣价： 502 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

5.1 Liquid penetrant examination methods indicate the presence, location, and, to a limited extent, the nature and magnitude of the detected discontinuities. This practice is normally used for production examination of large volumes of parts or structures, where emphasis is on productivity. This practice offers a wide latitude in applicability when extensive and controlled conditions are available.1.1 This practice describes procedures for visible liquid penetrant examination utilizing the water-washable process. It is a nondestructive practice for detecting discontinuities that are open to the surface such as cracks, seams, laps, cold shuts, laminations, isolated porosity, through leaks or lack of fusion and is applicable to in-process, final, and maintenance examination. This practice can be effectively used in the examination of nonporous, metallic materials, both ferrous and nonferrous, and of nonmetallic materials such as glazed or fully densified ceramics, and certain nonporous plastics, and glass.1.2 This practice also provides the following references:1.2.1 A reference by which visible penetrant examination procedures using the water-washable process can be reviewed to ascertain their applicability and completeness.1.2.2 For use in the preparation of process specifications dealing with the visible, water-washable liquid penetrant examination of materials and parts. Agreement between the user and the supplier regarding specific techniques is strongly recommended.1.2.3 For use in the organization of the facilities and personnel concerned with the liquid penetrant examination.1.3 This practice does not indicate or suggest criteria for evaluation of the indications obtained. It should be noted, however, that after indications have been produced, they must be interpreted or classified and then evaluated. For this purpose there must be a separate code, specification, or a specific agreement to define the type, size, location, and orientation of indications considered acceptable, and those considered unacceptable.1.3.1 The user is encouraged to use materials and processing parameters necessary to detect conditions of a type or severity which could affect the evaluation of the product.1.4 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.5 Basis of Application—There are areas in this practice that may require agreement between the cognizant engineering organization and the supplier, or specific direction from the cognizant engineering organization. These areas are identified as follows:1.5.1 Penetrant type, method and sensitivity,1.5.2 Accept/reject criteria,1.5.3 Personnel qualification requirements,1.5.4 Grit blasting,1.5.5 Etching,1.5.6 Indication/discontinuity sizing,1.5.7 Total processing time, and1.5.8 Marking of parts.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.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： 590元 / 折扣价： 502 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

This specification covers steel sheets used in the manufacture of corrugated steel pipe for storm sewers, culverts, drains, and similar uses. The sheet is metallic coated by the hot-dip process. Material for this use is furnished in coils, flat in cut lengths. The Zn-5A1-MM coating is available in two coating classes, the Class A which are minimized coating structure and Class B which are regular coating structure. The base metal cast or product analyses shall conform to the required chemical compositions for sulfur, and sum of carbon, manganese, phosphorus, sulfur and silicon. The zinc coating, zinc-aluminum-mischmetal alloy coating, aluminum-zinc alloy coating, aluminum coating type 2 and aluminum coating type 1 shall conform to the required coating bath composition. The metallic coating shall conform to the required mechanical properties such as tensile strength, yield strength and elongation.1.1 This specification covers steel sheet used in the manufacture of corrugated steel pipe for storm sewers, culverts, drains, and similar uses. The sheet is metallic coated by the hot-dip process. Material for this use is furnished in coils, flat in cut lengths, and corrugated in cut lengths. Many metallic coated materials are covered in this material specification. Users must determine which product best serves their needs. Five different metallic coatings are included:1.1.1 Zinc-coated (galvanized),1.1.2 Zinc-5 % aluminum-Mischmetal (Zn-5Al-MM) alloy coated,1.1.3 55 % aluminum-zinc (55Al-Zn) alloy coated,1.1.4 Aluminum-coated Type 2 (aluminized Type 2), and1.1.5 Aluminum-coated Type 1 (aluminized Type 1).1.2 Zinc-coated sheet is available in two coating weights [masses]. Other metallic coatings are available in one coating weight [mass] only.1.3 The values stated in either inch-pound units or SI units are to be regarded separately as the standard. Within the text, the SI units are shown in brackets. The values stated in each system are not equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.1.4 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： 590元 / 折扣价： 502 元 加购物车

定价： 843元 / 折扣价： 717 元 加购物车

This specification covers the requirements for chromium diffusion of metals applied by pack cementation process. The four classes of chromium diffusion coating, defined by the type of base metal, are as follows: Class I (carbon steels); Class II (low-alloy steels); Class III (stainless steels); and Class IV (nickel-based alloys). Specimens shall adhere to processing requirements such as substrate preparation, materials (masteralloys, activators, and inert fillers), loading, furnace cycle, post cleaning, post straightening, visual inspection, and marking and packaging. Specimens shall also adhere to coating requirements such as diffusion thickness, decarburization, chromium content, appearance, and mechanical properties (tensile strength, and macro- and micro-hardness).1.1 This specification covers the requirements for chromium diffusion of metals by the pack cementation method. Pack diffusion employs the chemical vapor deposition of a metal which is subsequently diffused into the surface of a substrate at high temperature. The material to be coated (substrate) is immersed or suspended in a powder containing chromium (source), a halide salt (activator), and an inert diluent such as alumina (filler). When the mixture is heated, the activator reacts to produce an atmosphere of chromium halides which transfers chromium to the substrate for subsequent diffusion. The chromium-rich surface enhances corrosion, thermal stability, and wear-resistant properties.1.2 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.1.3 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

This specification covers the requirements for aluminum diffusion of metals applied by pack cementation process. The three classes of aluminum diffusion coating, defined by the type of base metal, are as follows: Class I (carbon and low alloy steels); Class II (stainless steels); and Class III (nickel-based alloys). Specimens shall adhere to processing requirements such as substrate preparation, high and low activity pack mix, materials (masteralloys, activators, and inert fillers), loading, furnace cycle, post cleaning, diffusion heat treatment, post straightening, visual inspection, and marking and packaging. Specimens shall also adhere to coating requirements such as diffusion thickness, aluminum content, appearance, and mechanical properties (tensile strength, and macro- and micro-hardness).1.1 This specification covers the requirements for aluminum diffusion of metals by the pack cementation method. Pack diffusion employs the chemical vapor deposition of a metal which is subsequently diffused into the surface of a substrate at high temperature. The material to be coated (substrate) is immersed or suspended in a powder containing aluminum (source), a halide salt (activator), and an inert diluent such as alumina (filler). When the mixture is heated, the activator reacts to produce an atmosphere of aluminum halides which transfers aluminum to the substrate for subsequent diffusion. The aluminum-rich surface enhances corrosion, thermal stability, and wear-resistant properties.1.2 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.1.3 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

4.1 Use—This guide is intended to reflect a reasonable baseline process for the completion of PCAs for use on a voluntary basis. No implication is intended that use of this guide be required to have conducted a PCA in a commercially prudent and reasonable manner. The baseline process described in this guide is subject to a moderate level of uncertainty. Because the objectives, risk tolerance, schedule, and budget of users can be dramatically different there are varying levels of PCA and due diligence that can be exercised that are both more and less comprehensive than this guide that may be appropriate to meet the objectives of the user. In accordance with ASTM protocols, this guide does not recommend a specific course of action or scope of work. Users should consider their requirements, the purpose that the PCA is to serve, and their risk tolerance to refine the scope of assessment and consultant qualifications in order to establish appropriate objectives for the assessment.4.2 Clarification of Use of Assessments: 4.2.1 Specific Point in Time—A user should only rely on the PCR for the point in time that the observations and research were conducted.4.2.2 Site-Specific—The PCA prepared in accordance with this guide is site-specific in that it relates to the physical condition of primary improvements on a specific parcel of commercial real estate. Consequently, this guide does not address many additional issues in commercial real estate transactions such as economic obsolescence, the purchase of business entities, or physical deficiencies relating to off-site conditions.4.2.3 Specific Objectives—PCAs are completed to address specific objectives identified to the consultant by the user. The consultant should be consulted prior to use of the PCA to address any other objective.4.2.4 Intended Users—PCAs are typically completed for use by contracting parties. In some cases, the use of or reliance on reports may be extended to additional parties by mutual agreement of the contracting parties. Use of or reliance on PCAs by others may violate the rights of contracting parties and fail to satisfy the objectives of such unauthorized parties.4.3 Principles—The following principles are an integral part of this guide. They are intended to be referred to in resolving ambiguity, or in exercising discretion accorded the user or consultant in conducting a PCA, or in judging whether a user or consultant has conducted appropriate inquiry or has otherwise conducted an adequate PCA.4.3.1 Uncertainty Not Eliminated—No PCA can wholly eliminate the uncertainty regarding the presence of physical deficiencies and the performance of building systems or building components. Preparation of a PCR in accordance with this guide is intended to reduce, but not eliminate, the uncertainty regarding the potential for building system or building component failure and to reduce the potential that such building system or building component may not be initially observed. This guide also recognizes the inherent subjective nature of reported opinions as to such issues as workmanship, quality of original installation, and estimating the RUL of any given component or system. Users should work with their consultant to consider modifications to the scope of the PCA that may reduce uncertainties.4.3.2 Suggested Remedies—The guide recognizes that a suggested remedy may be determined under time constraints, formed without the aid of engineering calculations, testing, exploratory probing, the removal or relocation of materials, design, or other technically exhaustive means. Furthermore, there may be other alternatives or more appropriate schemes or methods to remedy a physical deficiency. The suggested remedies are generally formed without detailed knowledge from those familiar with the historical or actual performance of the building system or building component.4.3.3 Not Technically Exhaustive—The PCA is not intended to be construed as technically exhaustive. There is a point at which the cost of information obtained, or the time required to conduct the PCA and prepare the PCR, may outweigh the usefulness of the information and, in fact, may be a material detriment to the orderly and timely completion of a commercial real estate transaction. It is the intent of this guide to attempt to identify a balance between limiting the costs and time demands inherent in performing a PCA and reducing the uncertainty about unknown physical deficiencies resulting from completing additional inquiry.4.3.4 Representative Observations—The purpose of conducting representative observations is to convey to the user the expected magnitude of commonly encountered or anticipated conditions. Recommended representative observation quantities for various asset types are provided in Annex A1; however, if in the consultant’s opinion, the recommended representative observations are unwarranted as a result of homogeneity of the asset or other reasons deemed appropriate, the field observer may survey sufficient units, areas, buildings, building systems, and building components so as to comment with reasonable confidence as to the representative presence of physical deficiencies at such repetitive or similar areas, building systems, and building components. If there is more than one building on the subject property, and they are homogeneous with respect to approximate age, use, basic design, materials, and systems, it is not a requirement of this guide for the field observer to observe the building systems and building components within each individual building to describe or comment on their condition within the PCR. The descriptions and observations provided in the PCR are to be construed as representative of all similar improvements.4.3.4.1 User-Mandated Representative Observations—A user may mandate the representative observations required for a given subject property or a particular building system or building component. Such representative observations may be more or less detailed than this guide's recommended representative observations as provided in Annex A1.4.3.4.2 Extrapolation of Findings—Consultant 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 PCR and preparing the opinions of costs for suggested remedies.4.3.5 Level of Due Diligence is Variable—Not every subject property will warrant the same level of assessment. The appropriate level of assessment is guided by the purpose the PCA is to serve; type of subject property; age of the improvements; expertise and risk tolerance of the user; and time available for preparing and reviewing the opinions contained in the PCR.4.4 Prior PCR Usage—This guide recognizes that PCRs prepared in accordance with this guide may include information that subsequent users and consultants may want to use to avoid duplication and to reduce cost. Therefore, this guide includes procedures to assist users and consultants in determining the appropriateness of using such information. In addition to the specific procedures contained elsewhere in this guide, the following should be considered:4.5 Use of Prior PCR Information—Information contained in prior property condition reports may be helpful to assist in understanding the subject property and planning the walk-through survey and research for the completion of a current PCR. Such information should serve only as an aid to a consultant in fulfilling the requirements of this guide and to assist the field observer in the walk-through survey, research, and the field observer’s understanding of the subject property; and should be verified during the completion of a current assessment.4.5.1 Comparison with a Previously Prepared PCR—Discrepancies between a PCR and a previously prepared PCR are not indicative that either PCR is deficient. User requirements and objectives, the purpose of the PCR, qualifications and experience of the assessment team, time available to complete the PCR, access to and availability of information, hindsight, new or additional information, enhanced visibility because of improved weather or site conditions, equipment not in a shutdown mode, specific building systems and building components observed, and other factors may significantly impact the findings and opinions of the PCR. It should not be concluded or assumed that a previous PCR was deficient because the previous PCA did not discover a certain physical deficiency, or because opinions of costs in the previous PCR are different. Because a PCR contains a representative indication of the condition of the subject property at the time of the walk-through survey and is dependent on the information available to the consultant at that time, the PCR should be evaluated on the reasonableness of judgments made at the time and under the circumstances in which they are made.4.5.2 Conducting Current Walk-Through Surveys—At a minimum, for a PCR to be consistent with this guide, a new walk-through survey, interviews, and solicitation and review of building and fire department records for recorded material violations should be performed.4.6 Actual Knowledge Exception—If the user or consultant conducting a PCA has actual knowledge that the information from a prior PCR is not accurate, or if it is obvious to the field observer that the information is not accurate, such information from a prior PCR should not be used.4.7 Contractual Issues—This guide recognizes that contractual and legal obligations may exist between prior and subsequent users of PCRs, or between users and consultants who performed prior PCRs, or both. Consideration of such contractual obligations is beyond the scope of this guide. Furthermore, a subsequent user of a prior PCA should be apprised that the report may have been prepared for purposes other than the current desired purpose of the PCR and should determine the contractual purpose and scope of the prior PCA.4.8 Rules of Engagement—The contractual and legal obligations between a user and consultant (and other parties, if any) are outside the scope of this guide. No specific legal relationship between the user and consultant was considered during the preparation of this guide.1.1 Purpose—The purpose of this guide is to provide a framework for conducting a property condition assessment (PCA) of the primary improvements at commercial real estate properties by performing a walk-through survey and conducting research as outlined within this guide.1.1.1 Physical Deficiencies—The goal of the baseline process for property condition assessments is to identify and communicate material physical deficiencies to a user.1.1.2 Walk-Through Survey—This guide outlines procedures for conducting a walk-through survey to identify physical deficiencies, and recommends various building systems and building components that should be observed by the field observer.1.1.3 Document Reviews and Interviews—The scope of this guide includes document reviews, research, and interviews to augment the walk-through survey to assist with understanding the subject property and identification of physical deficiencies.1.1.4 Property Condition Report—The work product resulting from completing a PCA in accordance with this guide is a property condition report (PCR). The PCR incorporates the information obtained during the Walk-Through Survey, the Document Review and Interviews sections of this guide and includes opinions of costs for suggested remedies of observed physical deficiencies.1.2 Objectives—Objectives in the development of this guide are to: (1) provide a framework for conducting a property condition assessment (PCA) of the primary improvements located on a parcel of commercial real estate; (2) facilitate consistent and pertinent content in PCRs; (3) develop pragmatic and reasonable recommendations and expectations for site observations, document reviews and research associated with conducting PCAs and preparing PCRs; (4) establish reasonable expectations for PCRs; (5) assist in developing an industry standard of care for appropriate baseline observations and research; and (6) recommend protocols for the consultants for communicating observations, opinions, and recommendations in a manner meaningful to the user.1.3 Out of Considerations and Excluded Activities—The use of this guide is strictly limited to the scope set forth herein. Section 12 and Appendix X1 of this guide identify, for informational purposes, certain considerations and physical conditions that may exist on the 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 parties to a commercial real estate transaction to enhance the PCA. Users should work with a knowledgeable consultant to identify additional considerations and concerns to be evaluated. The decision to inquire into out-of-scope considerations or extend the assessment to include excluded activities is to be made by the user. No assessment of out-of-scope considerations is required for a PCA to be conducted in conformance with this guide.1.4 Organization of This guide—This guide consists of several sections, an Annex and two (2) Appendixes. Section 1 is the . Section 3 on Terminology contains definitions of terms both unique to this guide and not unique to this guide, and acronyms. Section 4 sets out the of this guide, and Section 5 describes the User's Responsibilities. Sections 6 through 11 provide guidelines for the main body of the PCR, including the scope of the walk-through survey, preparation of the opinions of costs to address physical deficiencies, and preparation of the PCR. Section 12 provides additional information regarding out-of-scope considerations, activities, and procedures (see section 1.3). Annex A1 provides guidance relating to specific asset types that are considered as integral to this guide. Appendix X1 describes additional concerns a user may consider in modification of the scope of the PCR. Appendix X2 and Appendix X3 outline an approach to limited accessibility screenings.     TABLE OF CONTENTS1    1.1 Purpose  1.2 Objectives  1.3 Out of Considerations and Excluded Activities  1.4 Organization of This guide  1.5 Multiple Buildings  1.6 Safety Concerns3 Terminology  3.2 Definitions  3.3 Abbreviations and Acronyms4   4.1 Use  4.2 Clarification of Use of Assessments  4.3 Principles  4.4 Prior PCR Usage  4.5 Use of Prior PCR Information  4.6 Actual Knowledge Exception  4.7 Contractual Issues  4.8 Rules of Engagement5 User's Responsibilities  5.1 Objectives and of Assessment  5.2 Point of Contact  5.3 Access  5.4 User Disclosure6 Property Condition Assessment  6.1 Objective  6.2 PCA Components  6.3 Coordination of Components  6.4 Consultant's Duties7 The Consultant  7.1 Qualifications of the Consultant  7.2 Staffing of the Field Observer  7.3 Independence of the Consultant  7.4 Qualifications of the Field Observer  7.5 Qualifications of the PCR Reviewer  7.6 The Field Observer and PCR Reviewer May Be a Single Individual  7.7 Not a Professional Architectural or Engineering Service8 Document Review and Interviews  8.1 Objective  8.2 Verification of Information Provided by Others  8.3 Accuracy and Completeness  8.4 Government Agency Provided Information  8.5 Pre-Survey Questionnaire  8.6 Owner/User Provided Documentation and Information  8.7 Interviews9 Walk-Through Survey  9.1 Objective  9.2 Frequency  9.3 Photographs  9.4   9.5 Additional Considerations10 Opinions of Costs to Remedy Physical Deficiencies  10.1 Purpose  10.2   10.3 Opinions of Costs Attributes11 Property Condition Report  11.1 Format  11.2 Writing Protocols  11.3 Documentation  11.4 Executive Summary  11.5 Purpose and   11.6 Walk-Through Survey  11.7 Document Reviews and Interviews  11.8 Additional Considerations  11.9 Qualifications  11.10 Limiting Conditions  11.11 Exhibits12 Out of Considerations  12.1 Activity Exclusions  12.2 Warranty, Guarantee, and Code Compliance Exclusions  12.3 Additional/General Considerations13 KeywordsAnnex A1 GUIDANCE AND ENHANCED DUE DILIGENCE SERVICES  A1.1 Multifamily Properties  A1.2 Commercial Office Buildings  A1.3 Retail Buildings   Appendix X1 GUIDANCE AND ENHANCED DUE DILIGENCE SERVICES  X1.1 Qualifications  X1.2 Modifications to the Baseline ProcessAppendix X2 AMERICANS WITH DISABILITIES ACT (ADA) ABBREVIATED ADA SCREENINGAppendix X3 FAIR HOUSING ACT (FHA) ABBREVIATED FHA SCREENING1.5 Multiple Buildings—If the subject property is comprised of multiple buildings, it is the intent of this guide that all of the primary improvements are discussed in one PCR.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.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 PDF includes GI #2, #3, #4 and #5. 1. Scope 1.1 This Standard applies to fixed equipment or accessories, or both, that utilizes signals to measure or control directly or indirectly an industrial process through a final control device (or devic

定价： 501元 / 折扣价： 426 元

5.1 The results of this test method may be used to determine nitrogen oxides and carbon monoxide emission concentrations from natural gas combustion at stationary sources.5.2 This test method may also be used to monitor emissions during short-term emission tests or periodically in order to optimize process operation for nitrogen oxides and carbon monoxide control.1.1 This test method covers the determination of nitrogen oxides (NO and NO2), carbon monoxide (CO), and oxygen (O2) concentrations in controlled and uncontrolled emissions from natural gas-fired reciprocating engines, combustion turbines, boilers, and process heaters using portable analyzers with electrochemical sensors. Due to the inherent cross sensitivities of the electrochemical cells, this test method should not be applied to other pollutants or emission sources without a complete investigation of possible analytical interferences and a comparative evaluation with EPA test methods.1.1.1 The procedures and specifications of this test method were originally developed during laboratory and field tests funded by the Gas Research Institute (GRI).2 Comparative emission tests were conducted only on natural gas-fired combustion sources. Subsequently, the U.S. Environmental Protection Agency (EPA) sponsored Environmental Technology Verification (ETV) program conducted further evaluations of electrochemical cell analyzers, which included laboratory tests and field tests on natural gas and diesel-fueled generators. The EPA has reviewed the ETV test results, published additional information, and provided technical input that has been considered in the update of this test method.31.2 This test method contains notes that are explanatory and are not part of the mandatory requirements of the standard.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 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.1.5 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： 646元 / 折扣价： 550 元 加购物车

4.1 Process Capability—Process capability can be defined as the natural or inherent behavior of a stable process that is in a state of statistical control (1).4 A “state of statistical control” is achieved when the process exhibits no detectable patterns or trends, such that the variation seen in the data is believed to be random and inherent to the process. Process capability is linked to the use of control charts and the state of statistical control. A process must be studied to evaluate its state of control before evaluating process capability.4.2 Process Control—There are many ways to implement control charts, but the most popular choice is to achieve a state of statistical control for the process under study. Special causes are identified by a set of rules based on probability theory. The process is investigated whenever the chart signals the occurrence of special causes. Taking appropriate actions to eliminate identified special causes and preventing their reappearance will ultimately obtain a state of statistical control. In this state, a minimum level of variation may be reached, which is referred to as common cause or inherent variation. For the purpose of this standard, this variation is a measure of the uniformity of process output, typically a product characteristic.4.3 Process Capability Indices—The behavior of a process (as related to inherent variability) in the state of statistical control is used to describe its capability. To compare a process with customer requirements (or specifications), it is common practice to think of capability in terms of the proportion of the process output that is within product specifications or tolerances. The metric of this proportion is the percentage of the process spread used up by the specification. This comparison becomes the essence of all process capability measures. The manner in which these measures are calculated defines the different types of capability indices and their use. Two process capability indices are defined in 5.2 and 5.3. In practice, these indices are used to drive process improvement through continuous improvement efforts. These indices may be used to identify the need for management actions required to reduce common cause variation, compare products from different sources, and to compare processes.4.4 Process Performance Indices—When a process is not in a state of statistical control, the process is subject to special cause variation, which can manifest itself in various ways on the process variability. Special causes can give rise to changes in the short-term variability of the process or can cause long-term shifts or drifts of the process mean. Special causes can also create transient shifts or spikes in the process mean. Even in such cases, there may be a need to assess the long-term variability of the process against customer specifications using process performance indices, which are defined in 6.2 and 6.3. These indices are similar to those for capability indices and differ only in the estimate of variability used in the calculation. This estimated variability includes additional components of variation due to special causes. Since process performance indices have additional components of variation, process performance usually has a wider spread than the process capability spread. These measures are useful in determining the role of measurement and sampling variability when compared to product uniformity.4.5 Attribute capability applications occur where attribute data are being used to assess a process and may involve the use of non-conforming units or non-conformities per unit.4.6 Additional measures and methodology to process assessments include the index Cpm, which incorporates a target parameter for variable data, and the calculation of Rolled Throughput Yield (RTY), that measures how good a series of process steps are.AbstractThis practice provides guidance for determining process capability and performance under several common scenarios of use including: normal distribution-based capability and performance indices such as Cp, Cpk, Pp, and Ppk; process capability using attribute data for non-conforming units and non-conformities per unit type variables; and additional methods in working with process capability or performance.1.1 This practice provides guidance for determining process capability and performance under several common scenarios of use including: (a) normal distribution based capability and performance indices such as Cp, Cpk, Pp, and Ppk; (b) process capability using attribute data for non-conforming units and non-conformities per unit type variables, and (c) additional methods in working with process capability or performance.1.2 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