Over deze norm
1.1 This practice describes procedures and methodologies based on the statistical principles of Practice D 6708
1.2 This practice assumes any correlation necessary to mitigate systemic biases between the analyzer system and PTM have been applied to the analyzer results.
1.3 This practice requires that both the primary method against which the analyzer is compared to, and the analyzer system under investigation, are in statistical control. Practices described in Practice D 6299
1.4 This practice applies if the process stream analyzer system and the primary test method are based on the same measurement principle(s), or, if the process stream analyzer system uses a direct and well-understood measurement principle that is similar to the measurement principle of the primary test method. This practice also applies if the process stream analyzer system uses a different measurement technology from the primary test method, provided that the calibration protocol for the direct output of the analyzer does not require use of the PTMRs (see Case 1 in Note 1).
1.5 This practice does not apply if the process stream analyzer system utilizes an indirect or mathematically modeled measurement principle such as chemometric or multivariate analysis techniques where PTMRs are required for the chemometric or multivariate model development. Users should refer to Practice D 6122
Note 1—For example, for the measurement of benzene in spark ignition fuels, comparison of a Mid-Infrared process analyzer system based on Test Method D 6277
1.6 Performance Validation is conducted by calculating the precision and bias of the differences between results from the analyzer system (or subsystem) after the application of any necessary correlation, (such results are herein referred to as Predicted Primary Test Method Results (PPTMRs)), versus the PTMRs for the same sample set. Results used in the calculation are for samples that are not used in the development of the correlation. The calculated precision and bias are statistically compared to user-specified requirements for the analyzer system application.
1.6.1 For analyzers used in product release or product quality certification applications, the precision and bias requirement for the degree of agreement are typically based on the site or published precision of the Primary Test Method.
Note 2—In most applications of this type, the PTM is the specification-cited test method.
1.6.2 This practice does not describe procedures for establishing precision and bias requirements for analyzer system applications. Such requirements must be based on the criticality of the results to the intended business application and on contractual and regulatory requirements. The user must establish precision and bias requirements prior to initiating the validation procedures described herein.
1.7 Two procedures for validation are described: the line sample procedure and the validation reference material (VRM) injection procedure.
1.8 Only the analyzer system or subsystem downstream of the VRM injection point or the line sample extraction point is being validated by this practice.
1.9 The line sample procedure is limited to applications where material can be safely withdrawn from the sampling point of the analyzer unit without significantly altering the property of interest.
1.10 Validation information obtained in the application of this practice is applicable only to the type and property range of the materials used to perform the validation.
1.11 Two types of validation are described: General Validation, and Level Specific Validation. These are typically conducted at installation or after major maintenance once the system mechanical fitness-for-use has been established.
1.11.1 General Validation is based on the statistical principles and methodology of Practice D 6708
1.11.2 When the variation in available validation materials is insufficient to satisfy the requirements of Practice D 6708
1.11.3 The validation outcome are considered valid only within the range covered by the validation material Data from several different Validations (general or level-specific) can potentially be combined for use in a General Validation.
1.12 Procedures for the continual validation of system performance are described. These procedures are typically applied at a frequency commensurate with the criticality of the application.
1.13 This practice does not address procedures for diagnosing causes of validation failure.
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 and health practices and determine the applicability of regulatory limitations prior to use.
|Engelse titel||Standard Practice for Validation of the Performance of Process Stream Analyzer Systems|