A photoelectric sensor with linear beam reduces installation costs and increases productivity

The client, with more than 2,500 outlets between the main stores of food in the USA, has carried out more than six logistics with Witrón project. This company plans, designs and implements all the logistics and systems of flow of materials, including data acquisition and control technology. Witrón also develops and produces the conveyor system and mechanical elements. In the new distribution center, the OPM (preparation of machinery orders) of Witrón system is responsible for the supply chain from receipt to delivery, in areas where normally there are no operators. The key factor is the innovative and patented ' case order machine' (COM). The challenge for Witrón is the fact that within the store, used to transport pallets of different height. This has as a result that is not always possible to detect them with a single sensor photoelectric reflex, since either their optimal alignment takes a long time or need to use a second photoelectric sensor. For this reason, Witrón proposed Sick to seek the best possible solution.

Detection of pallets of different heights with two 'classic' photocells would have increased the costs, it requires the installation, alignment and electrical connection of two sensors. The productivity of the plant has improved: because of the light beam linear of 50 mm which covers an area of homogeneous detection in comparison with the area of incomplete detection that is obtained when using two beams of light point, by the fact that the pallets are detected when they have imperfections or damage.

This light beam linear constant of 50 mm of height between photoelectric sensor and reflector is generated by the combination of a bright red light LED PinPoint and a special optical system. This allows a larger with a single sensor detection area, and can reliably detect objects greater than 12 mm, regardless of the position. PinPoint technology, the scope of the WL27-3 Reflex Array sensor is up to 4.5 meters. For Xavier Marza, head of products of industrial sensors from Sick, "the Reflex Array sensor provides reliability and allows us to provide an efficient solution in multiple logistics applications, including the detection of enfardados objects." "The Reflex Array sensor also avoids detect several times an object not uniform or with holes, improving the productivity of the installation".

With regard to the installation and commissioning of the Reflex Array sensors, the time is not a problem. A single sensor, a single connection, a single reflector minimize installation effort significantly compared to previous designs in technology. The same applies to the implementation in place. Thanks to the PinPoint LED linear beam of red light is very visible in the reflector. The alignment is facilitated with two LEDs placed in the casing of the sensor. If both are lit, it means that the alignment of the sensor and reflector is optimal. Flicker rate gives the information to the operator how should adjust the sensor to perform the alignment.

The decisive factor for this change is the compensation of the threshold of switching, which keeps an almost constant level the distance between the signal and the threshold of switching, otherwise gradually decreases due to the accumulation of dust and makes finally the photoelectric sensor does not work correctly and should be cleaned up. Reliable operation due to the light beam linear of 50 mm of the Reflex Array sensors, Sick has made available on the market since mid-2009, contributes significantly to increase the productivity of the Logistics Centre.