ISO/IEC TR 29158:2011 pdf free.Information technology — Automatic identification and data capture techniques — Direct Part Mark (DPM) Quality Guideline.
ISO/IEC TR 29158:2011 is an engineering document intended for verifier manufacturers and application specification developers.
ISO/IEC TR 29158:2011 was developed to assess the symbol quality of direct marked parts, where the mark is applied directly to the surface of the item and the reading device is a two-dimensional imager.
Direct Part Marking (DPM) is a technology whereby, generally, an item is physically altered to produce two different surface conditions. This alteration can be accomplished by various means including, but not limited to, dot peen, laser, ink jet, and electro-chemical etch. The area of the alteration is called “the mark”. The area that includes the mark and background as a whole, when containing a pattern defined by a bar code symbology specification, is called “a symbol”.
When light illuminates a symbol, it reflects differently depending on whether it impinges on the background of the part or on the physical alteration. In most non-DPM bar code scanning environments, light is reflected off a smooth surface that has been coloured to produce two different diffuse reflected states. The DPM environment generally does not fit this model because the two different reflected states depend on at least one of the states having material oriented to the lighting such that the angle of incidence is equal to the angle of reflection. Sometimes the material so oriented produces a specular (mirror-like) reflectance that results in a signal that is orders of magnitude greater than the signal from diffuse reflectance.
In addition, from the scanner point-of-view, some marking and printing methods generate dots and are not capable of producing smooth lines.
Current specifications for matrix symbologies and two-dimensional print quality are not exactly suited to reading situations that have either specular reflection or unconnected dots or both. This is intended to act as a bridge between the existing specifications and the DPM environment in order to provide a standardized image-based measurement method for DPM that is predictive of scanner performance.
This Technical Report is an engineering document intended for verifier manufacturers and application specification developers.
This Technical Report describes modifications which are to be considered in conjunction with the symbol quality methodology defined in ISO/IEC 15415 and a symbology specification. It defines alternative illumination conditions, some new terms and parameters, modifications to the measurement and grading of certain parameters, and the reporting of the grading results.
This Technical Report was developed to assess the symbol quality of direct marked parts, where the mark is applied directly to the surface of the item and the reading device is a two-dimensional imager.
When application specifications allow, this method may also be applied to symbols produced by other methods. This is appropriate when direct part marked (DPM) symbols and non-DPM symbols are being scanned in the same scanning environment. The symbol grade is reported as a DPM grade rather than as an ISO/IEC 15415 grade.