InteliSENS® SLR Series

InteliSENS® SLR Series - front view
InteliSENS® SLR Series - connector panel view
InteliSENS® SLR Series - connector panel view
InteliSENS® SLR Series - with optional AiG2 interface display unit



  • Non-contact, high-speed, solid-state laser speed and length measurement with no slippage, drift or mechanical wear and greatly reduced maintenance compared with contact wheel / roller systems.
  • Bidirectional speed and length measurement; accurately measures speed and length during line stoppage, reversal and creepage.
  • UKAS-traceable calibration; accuracy better than 0.05% and repeatability better than 0.02%.
  • Rugged industrial design for use in harsh factory environments.
  • Available fitted with industry-standard communcations interfaces for easy integration with PLCs and production line equipment.
  • Excellent value with low cost of ownership.

Additional Information:

Series Brochure
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Dimensional drawings
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Pre-sales enquiry click here >

Manual request click here >

Support request click here >

InteliSENS® SLR Series


Proton Products InteliSENS® SLR Series non-contact, bidirectional speed and length gauges provide extremely accurate speed and length measurements in almost any production environment.

Automatic direction detection and measurement down to zero speed means that the InteliSENS® SLR gauge length measurement counts both up and down, so final length measurements will still be accurate to 0.05% even with production lines that exhibit stoppage, direction reversal and creepage.

Production processes for wire, cable, web products, woven and non-woven materials, paper, plastic film, tapes, building materials, floorings and labelling can all be measured using the laser Doppler method.

Applications requiring a precise cut-to-length process benefit from the non-slip and highly accurate laser measurement technique which reduces scrap, increases uptime and improves material yield by eliminating product “Give Away” or “Short Length” claims.

InteliSENS® SLR Series gauges are money-saving, direct replacements for traditional problematic and high-maintenance contact wheel and roller-type devices and are extremely easy to install and operate. Integration with production line controllers such as PLCs is eased by the availability of a wide variety of industry standard communications interfaces.

Operating principle – Heterodyne laser surface velocimeter

Proton Products InteliSENS® Series speed and length gauges illuminate the measured surface with a precisely pitched interference pattern created by the intersection of two laser beams. The alternating bright and dark interference fringes modulate the light scattered by the object with a frequency proportional to the object speed. This scattered light is detected by a photodiode and the electrical signal digitally processed to determine the frequency and hence the speed. Object length is then calculated by integrating the speed measurement over time.

The InteliSENS® SLR series bidirectional speed and length gauges extend this principle by using a high-frequency Bragg cell modulator to illuminate the measured surface with a scanning interference pattern, which generates an oscillating light signal even when the object is stationary. Direction of motion is determined by whether the scattered light frequency is higher or lower than the stationary frequency.



Stand-off distance150300600mm
Maximum speed (bidirectional)250050005000m/min
Internal measurement rate100kHz
Measurement output interval40?s
Laser spot size3mm
Operating temperature545°C
Environmental protectionIP67
Power supply152425VDC
Power consumption20W
*only valid if the measured object is positioned within the central 20% of the depth-of-field.


Measurement units (end-user configurable)Speedmetres/minutefeet/minute
Laser safety control inputsLaserAn external closed SPST contact enables the laser diode.
ShutterAn external closed SPST contact opens the laser shutter.
2×Logic inputs (end-user configurable)ElectricalMaximum input voltage: +24Vdc
FunctionLength resetDisplay holdLength hold
Speed holdDirectionPause
3×Relay outputs (end-user configurable)ElectricalIsolated, floating relay contacts
Maximum voltage: 50VdcMaximum current: 0.5A
FunctionGauge OKLaser at tempShutter openLaser on
MeasuringPreset Length 1Preset Length 2
3×Pulse outputs (end-user configurable)ElectricalOpto-isolated differential pairs
Output voltage: 5V or user supplied (up to 24V)
Maximum frequency: 250kHz
Analogue output (end-user configurable)ElectricalOutput voltage: 0 to +10V (end-user scalable)
FunctionSpeedGood readings
CANbus communicationsConnects to an optional Proton Products AiG2 interface display unit
Serial communicationsRS-232RS-422 / 485
Optional communications (factory-installed, choice of one)PROFIBUSEthernet/IPDeviceNET
Optional wireless communications (factory-installed, choice of one)Bluetooth


Click here for information on accessories for the InteliSENS® SLR Series of laser speed and length gauges.