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Linear measurement over long sensing distances

Linear measurement over long sensing distances Where distances of linear travel are extremely long, for example with crane or gantry systems, laser distance sensors provide the only practical measurement solution. As well as providing reliable measurement for short ranges, they can also deliver non-contact distance measurement over tens or even hundreds of metres, at high accuracy and repeatability.

Different operating principles include the phase shift principle. Here, the laser signal is reflected directly back to the device - a technique that is generally more accurate than simple time of flight methods. Most surfaces will produce enough reflection to give an accurate reading; at the longest distances a special reflective plate is required to be affixed to the target.

Unlike pulse laser sensing techniques, phase shift laser distances sensors provide high accuracy over both long and short distances of measurement. and unlike laser triangulation sensors in which the laser transmitter and receiver are separated, the phase shift laser sensor can measure directly into a long bore or tube.

Long distance laser sensors are suitable for both dynamic and static applications. They can be used to measure distance, level and position, and to detect motion. Pairs of sensors can be mounted to measure thickness, length and diameter. Highly cost-effective, laser distance sensors are easy to set up and install.

Typical applications include use in small parts or pallet warehouses. In crane systems, laser distance sensors can be used for positioning as well as ensuring controlled synchronisation. In addition, laser distance sensors can be implemented to provide cut length monitoring on machinery to cut wooden beams, steel slabs, etc, all with millimetre accuracy. Other applications include level monitoring in mining applications, bar length and bar location.

Sensors UK offers a wide range of laser distance sensors to cover distances of hundreds of metres. For example, the FLS-C laser distance sensor measures absolute distances up to 500m, contact-free, with an accuracy of ±1mm. The repeat accuracy is ±0.3mm. Measurement values are updated at a frequency of up to 200Hz.

The measurement values are output via an SSI Interface which is fitted as standard. This ensures uncomplicated data exchange between the FLS-C transducer and a control system. As a result, the FLS-C laser distance sensor can be connected directly to a drive controller or a remote I/O SSI sensor interface from any manufacturer.

Where an external display is required to provide direct reading of the measurement results, the FLS-C can be connected to a display via inbuilt RS232 or RS422 interfaces. Thanks to its innovative laser technology, the FLS-C laser distance sensor can reliably measure distances to a huge range of different materials, including wood, steel, concrete and more. Irrespective of the type and colour of the material, the FLS-C laser distance sensor delivers measurement results with millimetre accuracy.

Constructed with a solid metal case, the FLS-C provides IP65 environmental protection, suiting to use both indoors and out, in the most demanding of industrial conditions. If equipped with the optional heating unit, these measuring devices also provide a robust and cost-efficient solution for extremely low ambient temperatures down to -40°C.

While a reflective plate would normally be required to be affixed to the target for distances over 65m, the FLS-C provides a special mode that can enable detection of natural materials at distances of up to 80m.
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