Color sensors

Color sensors detect colors by comparing the detected color value with a previously stored reference value. They are the right solution whenever the color of an object or marking can serve as a sorting or inspection criteria. Depending on the configuration and specified tolerance values of the system, the result is output as a switching signal.

Sensor technology for demanding color recognition and sorting tasks

Color sensors detect the color of an object or print mark and compare it to a set reference value. The special reflection diffuse sensors are used when the color is to serve as a distinguishing criterion. Color sensors are a cost-effective and compact alternative to image processing systems and are suitable for many industries: These include mechanical engineering as well as the automotive, plastics, pharmaceutical and packaging industries.

Color sensors can be used to detect, inspect and sort colored surfaces. The result is output to the control either as a switching signal or as an RGB color value via the IO-Link interface.

New CRT 648 color sensors: Easy operation and universal use

With their large LC display, the new CRT 648 series color sensors in robust die-cast zinc housings are easy to operate. Thanks to distance-independent color recognition, special luster suppression and seven pre-settable colors, the powerful sensors can be used flexibly. They are optimized for different applications: The CRT 648-32.G is ideal for detecting glossy surfaces thanks to its integrated polarization filter. If a small light spot is required, for example for the detection of print marks or small objects, the CRT 648-60 variant comes into its own. If the sensor is to be mounted further away from the object, the CRT 648-150 color sensors offer a particularly large working range.

Your benefit

Versatile use thanks to operating ranges of up to 150 mm and up to seven color settings
Simple operation and parameterization via integrated display or IO-Link
New application-optimized variants
- Detection of glossy surfaces through luster suppression
- New brightness evaluation with autocorrect enables a large tolerance in object guidance or distance-independent color recognition up to 65 mm
- Up to 7 colors can be evaluated with three binary coded outputs
- Optimized for use in demanding environments thanks to robust die-cast zinc housing with IP67 and IP69 protection classes, as well as ECOLAB certification

Go directly to CRT 648 item selection

Highlights

Simple operation: Quick teach-in process and seven color settings

The new CRT 648 color sensors are easy and intuitive to operate with a large, integrated LC display with keypad. The status of the switching outputs, a current color value output or the signal quality can be displayed as selected. If different product variants are tested in one system, up to seven color settings can be saved on the sensor and tested simultaneously. The large operating range opens up further possibilities: This means that one sensor can easily be used for different tasks – ensuring flexibility with increasing variation and reducing the outlay for additional sensors and set-up times.

Detects even subtle color differences, including in challenging conditions

Glossy objects are always a challenge for optical sensors. The new CRT 648-32.G color sensors are equipped with a polarization filter for reliable gloss detection. The evaluation of an object’s brightness, depending on its distance from the sensor, pose a further color recognition challenge. The CRT 648 color sensors’ brightness evaluation with autocorrect enables reliable and distance-independent color detection up to 65 mm.

Transparency and remote access via IO-Link

The new CRT 648 series color sensors can be set either remotely by teaching in via cable or via IO-Link, which is much more convenient. The format change can be simplified considerably via IO-Link and additional data can be recorded from the sensors.

The process at a glance:

Extensive timer functions for switch-on/-off delay and pulse suppression
Exact production figures known at all times thanks to the internal object counter
Real-time signal information as RGB color value output via IO-Link
Further diagnostic data such as temperature, signal quality, switching operations

Applications

Final inspection in food packaging

Requirement:
In a packaging system, the color of cereal bowls must be checked before they are placed in the container packaging. As the bowls are to be packaged according to type, it must be ensured that the same color comes off the conveyor belt every time.

Solution:
The new CRT 648 color sensors can be taught up to seven colors. They are equipped with a large light spot and reliably detect the colors of both the packaging and the cover. This way, incorrect or defective objects can be reliably distinguished. The large operating range of up to 150 millimeters ensures reliable detection, even when switching to other formats.

Monitoring of vials in pharmaceutical packaging

Requirement:
The quality requirements for pharmaceutical packaging are high. Defective vials, for example without caps, must be detected on the conveyor belt and ejected. The high-gloss vial caps pose a challenge for sensors.

Solution:
The CRT 648 color sensors with luster suppression detect the high-gloss vial caps while ensuring process stability. Operating and adjusting the sensors is quick and easy thanks to the large LC display.

Automated checks in car manufacturing

Requirement:
In the automotive industry, the color of rear lights is to be checked automatically at an assembly station. Two process steps must be covered: In the first process step, the connector color must be tested, and different test programs are then run depending on this. The second step in this application is to evaluate the light color and intensity of the rear light. Neither the ambient light nor the employee at the workstation may impair detection.

Solution:
In the first process step, a CRT 648 color sensor checks the color of the connector. Another CRT 648 checks whether the rear light has the correct light color and intensity.

Strapping machine for carton packaging / sealing

Requirement:
Different carton packaging items run on a conveyor belt. The appropriate strapping should be automatically selected to match the carton color.

Solution:
The CRT 648 series color sensors detect the carton color and transmit the information to the strapping machine. This allows the system to select the appropriate strap color.

Technical features

Feature	CRT648-32.G/L44-M12	CRT648-60/LT-M12	CRT648-60/L44-M12	CRT648-150/LT-M12	CRT648-150/L44-M12
Housing material	Metal, die-cast zinc	Metal, die-cast zinc	Metal, die-cast zinc	Metal, die-cast zinc	Metal, die-cast zinc
Operating range	18 … 32 mm	18 … 60 mm	18 … 60 mm	20 … 150 mm	20 … 150 mm
Light spot size	6x6 mm @ 25 mm	4x4 mm @ 40 mm	4x4 mm @ 40 mm	8x8 mm @ 60 mm	8x8 mm @ 60 mm
Number of colors	7	1	7	1	7
Number of switching outputs	3	1	3	1	3
Switching output	Push-pull (PNP/NPN configurable)	Push-pull	Push-pull (PNP/NPN configurable)	Push-pull	Push-pull (PNP/NPN configurable)
Switching input	Configurable (Teach, Trigger, Key Lock)	Teach	Configurable (Teach, Trigger, Key Lock)	Teach	Configurable (Teach, Trigger, Key Lock)
Switching frequency configurable	3 … 500 Hz	3 … 3000 Hz	3 … 3000 Hz	3 … 3000 Hz	3 … 3000 Hz
Ambient temperature (operation)	-20 … +55 °C	-20 … +55 °C	-20 … +55 °C	-20 … +55 °C	-20 … +55 °C
IO-Link data output	Switching outputs or color value output	Switching output	Switching outputs or color value output	Switching output	Switching outputs or color value output
Protection class	IP 67, IP 69	IP 67, IP 69	IP 67, IP 69	IP 67, IP 69	IP 67, IP 69
Certification	CE, UL, China RoHS ECOLAB, UKCA	CE, UL, China RoHS ECOLAB, UKCA	CE, UL, China RoHS ECOLAB, UKCA	CE, UL, China RoHS ECOLAB, UKCA	CE, UL, China RoHS ECOLAB, UKCA
Connection	M12 (5Pin)	M12 (4Pin)	M12 (5Pin)	M12 (4Pin)	M12 (5Pin)