Friday, November 21, 2008

How to Maintain Quality Standardization with AS9132

The aerospace industry, automotive industry and medical sectors are concerned about direct marking and traceability issues. Thanks to the highly developed reading and marking technologies of the present day, the problems inherent to the conventional and manual marking methods have been solved by the innovative automated marking technologies. This is why the AS9132 standard is extensively used for Dot Peen marking of Data Matrix codes.

People who are new to AS9132 might wonder what this standard is and why it is important. AS9132 is essentially a new Unique Item Identifier (UID) coding standard which defines the uniformity, quality and other technical requirements for Dot Peen marking and other metal components using Data Matrix symbologies. This AS9132 standard also defines the standard criteria essential to ensure electronic scanning or reading of the symbol. The AS stands for Aerospace standard. It was originally developed by the Society of Automotive Engineers (SAE).

Specific AS9132 guidelines with regards to the direct part marking of aerospace components have been issued by the Air Transport Association (ATA). These issued guidelines (SPEC 2000, Chapter 9) state that permanent part identification using bar code technology and, in particular, Data Matrix symbologies must be undertaken. The main objective is to mark a part with a ‘unique identifier’ to allow tracking of serialized parts during full life cycle of the parts and facilitate the use of automated processes in parts handling. Chapter 9 has explicitly mentioned data content although technical requirements or quality for Dot Peen and other marking technologies has not been mentioned.

AS9132 specifies uniform quality technical specifications that are required for 2D-Data Matrix symbols for direct marking onto the metal surfaces. This new standard AS9132 helps accessing the quality of Data Matrix symbols which are marked directly onto the surfaces of metal. AS9132 standardization helps evaluating the symbol quality and receives a PASS or FAIL based on the six parameters that are included in the standard.

The six parameters of AS9132 standard are described as follows.

· Symbol contrast: The difference in reflectance between the light and dark regions is the symbol contrast. But this symbol contrast doesn’t apply to Dot Peen dat a matrix symbols.

· Dot center offset: Dot center offset parameter refers to the deviation of a round element from the actual center of a cell.

· Angle of distortion: It is the amount of deviation from a 90degree relation between the X and Y axes. An acceptable angle of distortion is plus or minus 7 degree.

· Cell Fill: The percentage of ideal cell size that the element fills is called the cell fill area. 60% to 105% is the acceptable cell fill area.

· Dot Ovality: The extent to which round elements deviate from an ideal circle is called Dot ovality region. Up to 20% deviation is acceptable.

· Quiet Zone: At least one element in width, quiet zone is the unmarked area around the symbol.

Once the symbol quality clears all the parameters of AS9132 standard, the data matrix symbols now are ready to be used as per the Department of Defense (DoD) norms.

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