Xerox 6180N Generic MICR Fundamentals Guide  - Page 99

Voids Quality control 3. Look at the suspect character to see if its right edge falls between the two dotted lines defining the spacing tolerance zone. If the right edge of the character falls outside the dotted lines, it is outside the ±0.010 inch/0.25 mm leeway and is out of specification. It is also too close to, or too far away from, the character on its right. Additional tolerances are required between the fields in the MICR line to account for multiple printing steps. If a spacing problem occurs, verify that the job was written correctly and that the correct MICR font was used. Small spacing variations that accumulate over many characters affect MICR readability as long as the MICR line field boundaries are not violated. They are frequently the result of failure to properly specify character spacing or improper use of the spacing algorithm. The absence of ink is called a "void" or "deletion." Voids can be generated by excessive paper dust, a hardware problem, or excessive paper moisture. This problem occurs more often with cold fusion xerography and ionography technologies than with hot fusion based xerography (like Xerox MICR systems). Voids must be contained within a 0.008 inch/0.2 mm square. An exception is made for internal voids that extend over two or more zones of characters, a zone consisting of 0.013 by 0.013 inch/ 0.33 by 0.33 mm square. For such a situation, a void must fit within a 0.010 by 0.010 inch/0.254 by 0.254 mm square. The squares on the MICR Gauge can be used to test this. Single voids that are long, narrow, and predominately horizontal or vertical are called "needle" type voids. They are allowed in any length, anywhere in the character, provided they do not exceed 0.002 inch/0.05 mm in width. The combined areas of all voids in any vertical column or horizontal row (nominally 0.013 inch/0.33 mm wide) must not exceed 20 per cent. Generic MICR Fundamentals Guide 6-13