ASTM E2228-19

4.1 Microscopical examination is generally a non-destructive, rapid, and reproducible means of determining the microscopic characteristics, optical properties, and generic polymer type of textile fibers.

4.2 Point-by-point, side-by-side microscopic comparison provides a highly discriminating and efficient method of determining if two or more fibers can be differentiated.

4.3 This guideline requires specific pieces of instrumentation outlined herein.

1.1 This standard describes guidelines for microscopical examinations employed in forensic fiber characterization, identification, and comparison. A microscopical fiber examination can include a variety of light microscopes, such as stereomicroscope, polarized light, comparison, fluorescence, and interference. In certain instances, the scanning electron microscope can yield additional information. The particular test(s) or techniques employed by each examiner or laboratory will depend upon available equipment, examiner training, and the nature and extent of the fiber evidence.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 This standard cannot replace knowledge, skills, or abilities acquired through education, training, and experience and is to be used in conjunction with professional judgment by individuals with such discipline-specific knowledge, skills, and abilities.

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.