BS ISO IEC 15415:2011 pdf download.Information technology一Automatic identification and data capture techniques一Bar code symbol print quality test specification Two-dimensional symbols
5.1 General
The measurement of two-dimensional bar code symbols is designed to yield a quality grade indicating the overall quality of the symbol which can be used by producers and users of the symbol for diagnostic and process control purposes, and which is broadly predictive of the read performance to be expected of the symbol in various environments. The process requires the measurement and grading of defined parameters,from which a grade for an individual scan (scan reflectance profile grade or scan grade) is derived; the grades of multiple scans of the symbol are averaged to provide the overall symbol grade.
As a consequence of the use of different types of reading equipment under differing conditions in actual applications, the levels of quality required of two-dimensional bar code symbols to ensure an acceptable level of performance will differ. Application specifications should therefore define the required performance in terms of overall symbol grade in accordance with this standard. The guidelines in Annex D.4 are provided as an aid in writing application standards which employ this standard.
This standard defines the method of obtaining a quality grade for individual symbols. The use of this method in high volume quality control regimes may require sampling in order to achieve desired results. Such sampling plans, including required sampling rates are outside of the scope of this international standard.
5.4 Reporting of symbol grade
A symbol grade is only meaningful if it is reported in conjunction with the ilumination and aperture used. It should be shown in the format grade/aperture/lightangle, where:
●"grade" is the overall symbol grade as defined in 6.2.6 or 7.10, i.e. the arithmetic mean to one decimal place of the scan reflectance profile or scan grades,
●"aperture" is the aperture reference number (from ISO/IEC 15416 for linear scanning techniques, or the diameter in thousandths of an inch (to the nearest thousandth) of the synthetic aperture defined in 7.3.3),
●"light" defines the ilumination: a numeric value indicates the peak light wavelength in nanometres (for narrow band illumination); the alphabetic character W indicates that the symbol has been measured with broadband ilumination ("white light") the spectral response characteristics of which must imperatively be defined or have their source specification clearly referenced,
●"angle" is an additional parameter defining the angle of incidence (relative to the plane of the symbol) of the ilumination. It shall be included in the reporting of the overall symbol grade when the angle of incidence is other than 45°. lts absence indicates that the angle of incidence is 45°.
NOTE While ilumination from four sides with an angle of incidence of 45° is the default, other angles of incidence may be specified as requirements for grading by specifying the angle instead of leaving it blank. Other lighting options are defined in ISO/IEC TR 29158 which may be more appropriate for direct part marking applications,especially in applications which rely on symbols marked on reflectance substrates.BS ISO IEC 15415 pdf download.