Specifications

19
Stylus Type
A stylus is an object or instrument used
to activate a touch system, such as a finger,
pen, gloved hand, etc.
Calibration
Calibration is the process of adjusting
the active area of a touch system by
physically modifying the calibration
parameters of the touch (i.e., adjusting
potentiometers, setting EEROM parameters,
etc.). Although all touch systems require an
initial calibration during installation, only
systems that are subject to drift (where touch
targets gradually move away from the
desired locations) require routine or periodic
calibration.
n Capacitive and resistive overlay
systems are subject to drift and require
calibration, which generally consists of
adjusting the offset and scaling parameters to
make the touch area equal to, or greater in
size, than the display image.
n Surface acoustic wave, scanning
infrared, and guided acoustic wave are not
subject to drift and do not require calibration
after installation.
Integration
Integration is the process of attaching
the touch system to the display. Invasive
integration requires the disassembly of the
display to attach the touch system.
Typically, this type of integration results in
voiding the manufacturer’s warranties and
FCC certification. This type of integration
requires a skilled technician and usually
takes from 15 to 90 minutes.
Noninvasive integration does not
require disassembly of the display. This type
of integration can typically be done by
anyone and takes less than ten minutes.
Reliability
Reliability of a touch system refers to
how long it is expected to last before it fails.
Touch systems with polyester or conductive
coatings will fail after an anticipated number
of touches wear the coatings off. The
reliability of other touch systems that do not
wear out with use is measured in mean time
between failures (MTBF). This number is
normally derived by calculating the average
life expectancy of the electronic components
built into the touch system.