【国外标准】 Standard Test Method for Determining Plastic Film Thickness and Thickness Variability Using a Non-Contact Capacitance Thickness Gauge

5.1 This test method provides precise dimensions necessary for the calculation of properties expressed in physical units.5.2 This test method provides a means to characterize the variability of the material thickness in the transverse and machine directions for quality control purposes, production process support and analysis, incoming product inspection and for defining variability for buying/selling film.5.3 This test method provides a method for instrument calibration utilizing traceable standards available from the National Institute of Standards and Technology (NIST).5.4 It is not intended to replace other thickness measurements based on commercial portable tools, nor is it implied that thickness measurements made by different procedures will exactly agree.1.1 This test method covers the determination of the thickness of plastic film, ranging in thickness from 2.5 to 250 µm, with a non-contact thickness gauge that uses capacitance-based technology. It includes a method to generate a series of thickness data points that can be used to characterize the variability patterns of film for both transverse or machine direction (profiling).NOTE 1: Thicker specimens, typically 250 µm to 2500 µm thick, can utilize this test method if the apparatus is designed to measure and handle materials of this thickness range, and the apparatus complies with the requirements as defined in this standard.1.2 This test method provides a method for buyers and sellers of film to communicate the thickness and pattern of thickness variability of the product they are buying/selling.1.3 This test method does not apply to textured or porous films or films that are conductive or coated with a conductive substance.NOTE 2: Films that contain excessive levels of anti-static additive can be conductive and need to be tested to verify that they do not cause a negative reading on the instrument.1.4 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.NOTE 3: There is no known ISO equivalent to this standard.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.