Over the last 40 years, LaserSpeed®Pro gauges have set the standard of innovation for accuracy and reliability for non-contact length and speed measurement. Utilising the principle of Laser Doppler Velocimetry (LDV) LaserSpeed Pro can measure the velocity and length of a moving surface or object extremely accurately using a non-contact method. With over 20,000 installations worldwide in all types of in-process applications. The LaserSpeed® Pro gauges are suitable for use on any production line including materials as diverse as wires, cables non-wovens, extruded products, paper, plastic films, aluminium and steel. Regardless of your production line speed or product type, the LaserSpeed® Pro delivers precise, reliable measurements day in, and day out.
Incorporating a finely tuned optical engine combined with an ultra-stable laser diode enables the LaserSpeed Pro to deliver industry-leading measurement accuracy of better than ±0.03% and ±0.02% repeatability for the full depth of field.
The LaserSpeed® Pro gauges measures process speed and length using a non-contact method and is a direct replacement of existing contact rotary encoders to improve the accuracy and reliability of in-process measurement. Unlike contact encoders the LaserSpeed® Pro is not susceptible to errors due to slipping, wheel pick up, or wear and will provide a more dependable measurement over the long term. Material savings by improving the accuracy of measurement result in a very short payback period a major impact on the bottom line.
The LaserSpeed® Pro gauges embrace Industry 4.0 connectivity, which means integrating more easily than ever into production networks to provide real-time data exchange and improve process control and efficiency.
With 8 versions available covering stand-off distances from 100 to 3000 mm, there is a model available for any type of production line including ultra-harsh applications found in steel mills measuring red hot steel. The LaserSpeed Pro range features powerful capabilities in connectivity, using industry-standard protocols communication. Integrates seamlessly with any production networks, providing real-time data exchanges and tight process control. A full range of options and accessories enable easy integration and reliable operation in all types of production environments.
The LaserSpeed® Pro 4500 Series is our most cost-effective non-contact speed and length gauge, ideal for measuring continuous products with an accuracy better than ±0.03%.
The LaserSpeed® Pro 8500 Series delivers proven and cost-effective non-contact speed and length measurement, with discrete part inspection for 100% quality control.
The LaserSpeed® Pro 9500 Series is our most advanced non-contact velocimeter and length gauge, measuring zero speeds and tracking product direction with an accuracy better than ±0.03%.
The patented LaserSpeed® Pro M Series non-contact velocimeter and length gauge delivers precise speed and length measurements for small, vibrating wires, cables, and rods.
The LaserSpeed® Pro E Series includes a compact secondary housing to protect the speed sensor against hot or hostile environments in metals manufacturing.
The LaserSpeed® Pro 8500X and 9500X Series laser Doppler gauges feature secondary stainless steel housings for robust protection in harsh casting and rolling mill conditions.
The LaserSpeed® Pro C-Frame is equipped with 90-degree angled optics tailored for laser velocimetry within X-ray thickness gauges used in C-Frames across the metals industry.
Arrange a call with a product specialist to find out how a non-contact measuring system from LIMAB UK could benefit your company.
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| Elongation/differential speed measurement | Coil length or speed measurement | Cut-to-length control |
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| Hot section saw control | Tube length measurement | Continuous caster speed & length measurement |
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| Billet or section length measurement | Process speed or stretch levelling | Forward/reverse positioning applications |
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Feature |
LS4500 |
LS8500 |
LS8500 M Series |
LS9500 |
| Accuracy | <±0.03% of reading | <±0.03% of reading | <±0.05 -0.1 % of reading depending on version | <±0.03% of reading |
| Repeatability | ±0.02% | ±0.02% | ±0.02% | ±0.02% |
| Internal measuring rate | 20KHz | 50KHz | 50 KHz | 100KHz |
| Measures zero speed | ❌ | ❌ | ❌ | ✔ |
| Measures forward & reverse | ❌¹ | ❌¹ | ❌¹ | ✔ |
| Start/End detection | ❌ | ✔ | ✔ | ✔ |
| Internal material detection | ❌ | ✔ | ✔ | ✔ |
| Measures object hotter than 700°C | ❌ | ✔² | ✔² | ✔² |
| Elongated spot (for bouncing or unguided products) | ❌ | ❌ | ✔ | ❌ |
| Output update rate | 2 to 64 ms in 2 ms increments | 1 to 2000 ms in 1 ms increments | ||
| Serial output | RS232 | RS232 & RS422 | ||
| Quadrature output frequency max | 250KHz | 5Mhz | ||
| C Series available (90° angle optic) | ❌ | ✔ | ❌ | ✔³ |
| E Series available (protection housing) | ❌ | ✔ | ✔ | ✔ |
| X series available (SS protection housing) | ❌ | ✔ | ✔ | ✔ |
| Stand off versions / Depth of field (mm) | 100 / 15 300 / 35 600 / 50 |
300 / 20⁴ 600 / 50 1000 / 100 |
300 / 35⁴ 600 / 30 1000 / 40 |
300 /35⁴ 600 / 50 1000 / 100 1500 / 200 2000 / 200 2500 / 200 3000 / 200 |
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LS 8500 M |
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¹ Requires forward/reverse signal
² Not including the 300 and 1000 mm stand off versions
³ Only available for 600 & 1000 mm stand off versions
⁴ Not available E or X Series
A laser surface Doppler, sometimes referred to a Laser Doppler Velocimeter (LDV), is an instrument used for measuring the velocity of a moving surface or object using a non-contact method. The instrument is also able to determine length as this is calculated by integrating the velocity over time. The device emits two laser beams of the same wavelength that converge to form a single spot at the surface. When two laser beams cross interference pattern is formed known as a fringe pattern (see diagram). The fringe separation or distance is a constant and a function of laser wavelength and beam angle. By measuring the frequency of scattered light emitted from the object as the surface particles pass through the fringes the velocity of the surface can be calculated.
The fringe separation or distance is a function of laser wavelength and beam angle.
Velocity is distance over time.
Period is the inverse of frequency.
Velocity is integrated to determine length
The LaserSpeed Pro uses the principle of Laser Doppler Velocimeter (LDV) to provide non-contact measurement of velocity of a moving surface or object. Since length can be calculated by integrating the velocity over time it is also possible for the LaserSpeed to provide both measurement of velocity and length simultaneously.
Velocity is integrated to determine length.
LaserSpeed Pro gauges can be used for any application where it is important to have accurate speed and length measurements. They are capable of measuring any type of material, metallic or non–metallic, in any colour or surface finish and any temperature including red-hot metals. They are widely used to measure the length of a product during the manufacturing process. Many products are sold by length and supplied in spools, reels or coils formats. It is important that the manufacturer ensures that each spool produced is supplied to comply with the length specification. Examples of length measurement applications are cables, wire, paper, foil, steel strip coils, aluminum strip coils, film reels, various web products, laminates to name a few. Another common application is where a continuous length of product is manufactured and needs to be cut to shorter lengths to be sold to the customer. This will be done using a cut-to-length line where a shear or saw cuts the moving product to shorter lengths. The LaserSpeed Pro can be used to accurately control this operation. Other manufacturing processes require real-time speed measurement where the LaserSpeed Pro will provide very precise speed measurement even on rapidly accelerating or decelerating processes.
The longer stand off (1.5, 2.0, 2.5 & 3.0m) versions of LaserSpeed Pro LS8500 or LS9500 E or X series gauges are designed to measure both hot or cold materials out of the box. Making them suitable for all applications found within the steel manufacturing process from continuous casting to final processing of cold product. LaserSpeed Pro gauges are ideal for non-contact speed and length measurement on steel billet or slab casters and hot rolling mills with product temperatures up to 1350°C. The E or X series have air- or water-cooling facility built into the housing to protect the gauges from excessive heat radiation.
There is a wide range of LaserSpeed Pro models which are suitable for any non-contact speed or length measurement application found within industry. The key considerations for selecting the right model are as follows: –
Stand-off Distance (SO):
This is the mounting distance from the object to be measured and the aperture window on the LaserSpeed Pro. It is defined as the distance to the centre of the depth of field (DOF). When measuring very hot materials (red hot steel for example) it is an advantage to have a longer stand-off distance to keep the LaserSpeed Pro at a safe distance. With other applications, for example on cold materials, there may be limited space so having a shorter stand-off will be an advantage. The stand-off distance does not affect the measurement performance or accuracy.
Options available (model dependent)
100mm
300mm
600mm
1000mm
1500mm
200mm
2500mm
3000mm
Depth of Field (DOF)
The material being measured must be within the depth of field (DOF) for correct measurement. The DOF increases as the stand-off increases (see table below). It might be an advantage to choose a model with a longer stand-off to ensure that the gauge has a sufficient DOF for the application in mind.
| Stand – off (SO) | Depth of field (DOF) |
| 100 mm | 15 (±7.5) |
| 300 mm | 35 (±17.5) |
| 600 mm | 50 (±25) |
| 1000 mm | 100 (± 50) |
| 1500 mm | 200 (± 100) |
| 2000 mm | 200 (± 100) |
| 2500 mm | 200 (± 100) |
| 3000 mm | 200 (± 100) |
Zero speed and very slow measurement
The LaserSpeed Pro LS4500 & LS800 models are not able to measure very slow speed (for example below 0.4 m/min for the LS4500-403 model). Therefore, on processes that are creeping very slowly, inching back and forth or moving in both directions the LaserSpeed LS9500 model should be selected. This model can measure zero speed and track direction.
Harsh environments
For applications with harsh environments, such as elevated ambient temperature, steam or dust contamination, it is important to select a model that is designed to operate reliably in this type of situation. These are most common in steel mills where the LaserSpeed Pro is used to measure red hot steel in a hot mill or continuous caster and the gauge needs to be cooled due to the high ambient temperatures and the optic needs to be kept clean with an air purge. For these applications, either the LaserSpeed Pro E Series or X Series should be selected.
The LaserSpeed Pro gauges simultaneously measure both speed and length. The speed and length data is available on all the digital outputs at a user selectable update rate. The update rate range is preset between 1-256ms.
“Accurate length control at the hot saws is critical to our operations, we needed to work with a company that understood our requirements and had the know-how to deliver an effective solution. LIMAB Ltd exceeded our expectations in delivering a turn-key measuring system that will improve our efficiency.”
“We wanted to improve the accuracy and repeatability of the automated length cutting operation on our Agnati corrugator. From the first meeting, it was clear that LIMAB have a lot of experience in this area and they replaced our mechanical encoder with a LaserSpeed. The implementation of the LaserSpeed has enabled us to achieve our original goal and it has ultimately improved the quality of the products that we are supplying to our customers.”
“We have been very impressed with LIMAB UK as they clearly have a lot of experience in this area and they have helped us to make an extremely successful installation. I would definitely use LIMAB UK again and would have no hesitation in recommending them.”
We believe our customers should deal with an expert from the point of enquiry to project completion. Therefore, we will appoint you a product specialist, so you have continuity and a single point of contact. They will be your guide, help identify the best solution for your particular application and be with you through to successful implementation.
Arrange a call with a product specialist to find out how LIMAB UK could benefit your company.
