Signal Strength - Xerox 6100BD - Phaser Color Laser Printer Fundamentals

Quality control

Signal strength

Signal strength or level is the relative ability of magnetic ink
characters to generate a signal in an electromagnetic sensing
device. The signal strength is a percent of a nominal value for
each character. The ANSI specification is 50% to 200% of the
nominal specified peaks signal for each character.
NOTE: Under normal conditions, the signal strength of a Xerox
MICR printing system does not require measurement unless
some degradation of MICR quality is observed during inspection.
Information on MICR signal level measurement is provided here
for those customers who have access to magnetic signal
strength test equipment.
As a document passes over the read head of the reader sorter,
the magnetized particles in the MICR ink cause a flux change
within the windings of the read head, changing the output
voltage. This voltage passes through an amplifier and is
translated into readable signals that can be recognized and input
to a computer. Each MICR character has a nominal signal
strength and wave shape. If the level is either too high or too low,
the reader sorter is not able to properly identify the characters.
Generic MICR Fundamentals Guide 6-17