InteliSENS® SLRM Series

InteliSENS® SLRM6060 / SLRM120120 - front view
InteliSENS® SLRM Series - rear view
InteliSENS® SLRM Series - connector panel view
InteliSENS® SLRM200100 - front view



  • 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.
  • Harsh environment enclosures are available from Proton Products on request.

Additional Information:

Series/Application Brochure
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InteliSENS® SLRM Series


InteliSENS®Proton Products InteliSENS® SLRM Series non-contact, bidirectional speed and length gauges provide extremely accurate speed and length measurements for metals industry applications. They are available with extended stand-off distances and greater depth-of-fields than the standard InteliSENS® SL Series gauges, which allows them to be used to measure very high temperature objects such as in hot-rolling processes.

Automatic direction detection and measurement down to zero speed means that the InteliSENS® SLRM 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.

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® SLRM 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® SLRM 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.



Model SLRM6060120120150200200100200200250200Units
Stand-off distance*60012001500200020002500mm
Maximum speed (bidirectional)5000100001000050001000010000m/min
*Other stand-off distances are available on request.
Internal measurement rate100kHz
Measurement output interval40µs
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® SLRM Series of laser speed and length gauges.