colorSENSOR offers stable measurements and high resolution

True colour recognition is required in many industry sectors, enabling companies to select, monitor, grade and sort various types of coloured objects involved in manufacturing, automated handling, warehousing, packaging, wrapping and other production processes. Measured objects can take the form of solids or liquids, and colour sensors are also suitable for use on transparent surfaces such as coatings or labels, as well as LEDs or lamps.

With its new colorSENSOR series, Micro-Epsilon is offering customers one of the widest ranges of colour recognition sensors in the world. This range includes the colorSENSOR LT sensors that operate using optical fibres. Here, the sensor is connected to an optical fibre that is guided to the measurement target. Colour detection therefore takes place very close to the object, which reduces any environmental effects that could adversely affect the reliability of measurements. More than 2000 different types of fibre optic cable are available, as well as a large number of lenses. These provide customers with an almost unlimited number of combinations of sensor and optical fibre, which, in turn, enables Micro-Epsilon to help customers select the optimum colour recognition sensor for any given application.

Extensive choice

The colorSENSOR LT range includes low-cost, entry-level sensors through to high-precision, multi-channel colour recognition systems. The LT range offers measuring distances from 2-100mm and up to 255 colour memory locations (NB multiple shades of the same colour can be taught if required). As well as exact colour, these memory options enable users to store specific tolerance limits for different applications. During colour recognition inspection, the sensor compares the colour it has been taught with the colour currently detected. The results are then made available via digital interfaces (RS232 or USB) as discrete values/numbers or OK/NOK (pass/fail) statements. The sensors are supplied with their own set-up and configuration software and a graphical user interface (GUI) that enables users to adjust the sensor to suit different applications.

Using new LED light sources, the LT sensors can be mounted further away from the measurement target if required, at distances of up to 2000mm. Micro-Epsilon claims that a unique feature of the product family is that inputs from multiple fibre-optic sensors can be connected to a single control unit (eg for testing numerous LEDs in an automotive light cluster), which can result in substantial savings compared with using multiple integrated sensor/control devices.

Other benefits of the Micro-Epsilon colour sensors is that the fibre-optic sensors can have a very small spot size, hence small components can be inspected. Alternatively, wider optics can be used to inspect inhomogeneous products such as wood grain.

Fixed optics

Micro-Epsilon's colorSENSOR OT family of colour recognition sensors operates by using fixed optical systems. These sensors recognise the colour of objects from longer distances (from 2mm to 800mm). Different models are available to suit different surfaces and materials, including shiny, reflective and structured surfaces, and there are versions for recognising UV (ultraviolet) markings. OT sensors can even recognise colour variations along or between target objects and materials. This is particularly beneficial to manufacturers of vehicle interiors, leather, embossed film, fabrics, wood veneers and large painted components, where small colour variations are not acceptable to customers.

OT sensors use eight white-light LEDs, whose brightness can be controlled as required. These LEDs are used as light sources for diffuse illumination. The switching status is displayed using five yellow LEDs. The sensors are insensitive to external light and have a true colour detector that filters RGB values in a similar way to the human eye. However, a 'best hit' mode uses vector formation to show colours that are so similar that they are almost indistinguishable to the human eye. This provides customers with unambiguous, process-safe colour differentiation.

Teach-in configuration

All of the Micro-Epsilon colorSENSOR products benefit from a 'teach-in' function that enables the sensor to learn and adapt to the application by using samples of the correct colour.

As well as the sensors suitable for product differentiation and grading by colour, other models in the colorSENSOR series enable the position monitoring of objects such as pallets, tiles, textiles, granulates, pills, soldering points, food products and liquids. Colour recognition sensors are also available for observation tasks, including the degree of ripeness of fruit, coated foods, varnish and coloured liquids.

Outside the UK, the colorSENSOR series has already found applications in numerous industry sectors, including automotive (vehicle interiors and paintwork), machine building and automation, electricals, chemicals, pharmaceuticals, cosmetics, medical, food and beverage processing, agriculture, security, paper, printing and packaging.

Attractive pricing

Chris Jones, Managing Director of Micro-Epsilon UK, comments: "The new colorSENSOR range offers UK customers an unrivalled combination of high resolution and high reliability with a very attractive price tag starting from less than 500.

"In addition, the colorSENSOR LT range offers up to 20 times higher resolution than alternative colour sensors currently available on the market. Our LT range offers a best resolution of delta E 0.4, whereas other competing sensors start at 0.8. This compares with the human eye that can only resolve colour values of 1.3 to 1.5."

Follow the link for more information about Micro-Epsilon's colorSENSOR colour sensors. Other products for colour sensing are expected to be launched by Micro-Epsilon in 2012.