LaserSpeed®Pro LS4500

Non-Contact Speed Measurement

Non-contact Speed Measurement


Over the last 30 years, LaserSpeed® gauges have set the standard of innovation for accuracy and reliability for non-contact length and speed measurement. With over 8,000 installations worldwide in all types of in-process applications. The LaserSpeed® Pro LS4500 is suitable for use on any production line including materials as diverse as non-wovens, mineral wool, paper and plastic films wood panels or insulation materials. Regardless of your production line speeds or product type the LaserSpeed® Pro LS4500 delivers precise, reliable measurements day in, day out.

The LaserSpeed® Pro LS4500 measures process speed and length using a non-contact method and is a direct replacement of existing contact rotary encoders to improve accuracy and reliability of in-process measurement. Unlike contact encoders the LaserSpeed® Pro LS4500 is not susceptible to errors due to slipping, wheel pick up or wear and will provide a more dependable measurement over the long term. The LaserSpeed® Pro LS4500 is the most accurate gauge available on the market today delivering an accuracy of better than ±0.03% and repeatability of ±0.02% on any material irrespective of the surface properties. The LaserSpeed® Pro LS4500 embraces Industry 4.0 connectivity, which means integrating more easily than ever into productions networks for providing real-time data exchange and for improving process control and efficiency.

For use in the metals industry please view our LaserSpeed®- Metals LS8500 and LS9500 models.

LaserSpeed® Pro LS4500 Applications

Spool Length Measurement Speed Differential Measurement Cut-to-length Shear Control
Non-contact Speed Measurement Non-contact Speed Measurement
Speed Matching Printing/marking Control  Machine Speed Calibration
Non-contact Speed Measurement Non-contact Speed Measurement Non-contact Speed Measurement

Operating Principle

LaserSpeed® Pro LS4500 gauges use the principle of dual-beam laser Doppler velocimetry combined with autocorrelation algorithm to delivery outstanding ability to track minute rapid changes in surface speed. The gauge uses the latest solid state technology with no moving parts providing a stable measurement and permanently calibration.


  • Speed synchronisation on converting machines
  • Saw control on wood-based panels
  • Length measurement of paper reels
  • Length control in sawmills
  • Length measurement of stone or glass wool
  • Accurate speed and length of non-woven materials
  • Length control on gypsum board lines
  • Length of soft insulation materials
  • Speed calibration on printing machines
  • Cut-to-length shear control
  • Speed or length of process lines
  • Carpet length



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.

Shaun Coombs – Engineering Manager

Other LaserSpeed models

For use in the metals industry please view our Laserspeed Pro -Metals LS8500 and LS9500 models.

LaserSpeed® pedigree

LaserSpeed® gauges can measure the speed and length of any products using an optical, non-contact technology called Dual Beam Laser Doppler Velocimetry. LaserSpeed gauges were first introduced to the metals industry in 1984 and have been growing in usage ever since. There are now thousands of LaserSpeed gauges installed in all types of industrial applications worldwide.

High performance

A breakthrough in electro-optics design enables LaserSpeed gauges to produce highly accurate, non-contact speed and length measurements at a reasonable cost. To accomplish this the LaserSpeed gauge uses Laser Doppler Velocimeter technology coupled with autocorrelation, the most advanced, digital signal processing algorithm and a new single-chip integrated circuit technology. LaserSpeed gauges have no moving parts, use 100 % solid-state digital technology, and are permanently calibrated – resulting in significant time and money savings.

Replace contact tachometers

With an accuracy better than ±0.03%, irrespective of the material, temperature, surface or speed the LaserSpeed is ideal for replacing traditional contact tachometers that are prone to measurement errors caused by slippage, dirt build-up, and day-to-day wear problems.

Suitable for harsh environments

All LaserSpeed gauges are extremely rugged with a sealed IP67 housing with built-in air/water cooling facility. Suitable for installation in tough industrial applications.

LaserSpeed Pro LS4500

Features Benefits
Non-contact measurement Materials that are impossible or difficult to measure with traditional contact methods due to slip or wear can now be measured accurately
No maintenance There is no wear compared with contact roll measuring systems, significantly reducing running costs and on-going maintenance
High accuracy Measuring to better than ±0.03% means better process control and saving in material and better quality
Rugged construction Suitable for use in any online process application
Permanent calibration Reduces running costs as frequent recalibration is not required
Industry 4.0 connectivity Easy integration to industrial data networks
LaserTrak software Supplied with simple windows software to configure the sensor
Options & accessories Large range of accessories means that the sensors are suitable for most applications straight out of the box

LaserSpeed Pro LS4500 specification

Model Stand off
Depth of
field (mm)
range (m/min)
LS4500-401 100 15 0.2-1700
LS4500-403 300 35 0.4-4000
LS4500-406 600 50 0.8-8000
LS4500-410 1000 100 1.0-12000
Accuracy <±0.03% of reading
Repeatability ±0.02%
Measuring rate >20,000/sec
Acceleration rate >500 m/s²
Output rate 2 – 32 ms in 2ms increments
Serial I/O RS232, speed, length, quality factor, status
Quadrature pulse output 1 Selectable pulse rate up to 250 kHz
Quadrature pulse output 2 Selectable pulse rate up to 250 kHz
Index pulse output yes/programmable
Analogue output 0-2 V velocity or QF
Ethernet 10/100 UDP, TCP, speed, length, Quality factor, status
Fieldbus Ethernet (Modbus TCP, Ethernet IP, Profinet IO); Profibus DP
Gauge power 24VDC (±4) @ 1.0 Amp
Gauge temperature 5 to 45 °C
Gauge size 203 x 159 x 87.6 mm
Degree of protection IP67