Delta CS64A - Manual (Page 5)

5
Introduction
The CS64A color sensor contains a light generation system to illuminate the object to be
sensed, and a light receiving system to read the diffuse reflected light from the object.
The light generation system consists of four sets of light emitting diode (LED) light
sources—a total of 28 LEDs. The CS64A determines color by turning on just one set of
LEDs (one color) at a time and analyzing the light captured by it’s precision silicon
photodiode.
The CS64A color sensor reads four different wavelengths--Blue, Near-infrared (NIR),
Red, and Green. Reflected energy in each of the color ranges appears as a 0-10V signal
on the corresponding four analog outputs, making the CS64A compatible with any PLC,
PC, or system having 0-10V analog inputs.
Using the ratios of Red/NIR, Blue/NIR and Green/NIR, it is possible to distinguish
between a wide range of colors. Very similar colors typically have a 10% difference in at
least one ratio, while some colors may have ratio differences 70% or more.
The CS64A was developed specifically for on-line color sensing applications, including:
• Distinguish between objects to ensure the correct color object is being processed on
your automated production line, such as vehicle headliners, door and body panels,
and seats
• Sort objects by color
• Monitor color variations of materials during manufacture such as carpets and ceramic
tile
• Detect presence of metal coatings or wood varnish
• Monitor color quality of granular foods such as sugar
• Detect paint marks where bar coding is impractical
• Detect over- or under-cooked baked goods
The diffuse LED lighting and large sensing area make the CS64A relatively immune to
material grain direction and similar variations. The CS64A-00's long standoff distance of
1.75 to 2" and sensor-to-target distance variation tolerance of 1.25 to 2.5" are important
benefits in many applications as well. The CS64A-02 has an extended standoff distance
of 4.75-5.00” while the CS64A-04-BNR has a very wide working range of 2.75” (3.00 to
5.75” sensor-to-object).
Each of the CS64A’s four 0-10V analog outputs has an adjustment potentiometer and an
indicator LED. The indicator LEDs come on when the output reaches about 2 volts and
the indicator LED intensity increase with amplitude.
The high-intensity LEDs in the CS64A’s lighting system have a typical life of 100,000
hours. (Actual intensity is 64 times higher than it appears since the LEDs are pulsed at a
low duty cycle).
The intensity of all LEDs varies with temperature due to the properties of the
semiconductor materials used. The CS64A sensors use feedback circuitry to maintain
amplitudes over a wide range of temperature and to compensate for light loss due to
normal LED aging. This feedback along with the long life of the LEDs, greatly reduces
the need for recalibration.