InteliSENS® SLR mini Series

InteliSENS® SLR mini - front view
InteliSENS® SLR mini - display
InteliSENS® SLR mini - connector panel
InteliSENS® SLR mini - with mobile phone for size comparison



  • Non-contact, high-speed, solid-state laser speed and length measurement with no slippage, drift, mechanical wear or maintenance compared with contact wheel / roller systems.
  • Wire optomized SL mini-W series version available for wire and cable applications
  • Bidirectional speed and length measurement; accurately measures speed and length during line stoppage, reversal and creepage.
  • Ultra-compact design with a footprint comparable to a smartphone.
  • Optimized for sheet material and converting applications.
  • UKAS-traceable calibration; accuracy better than 0.05% and repeatability better than 0.02%.
  • Rugged industrial design for use in 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 – English
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Series Brochure – German
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Series Brochure – French
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Series Brochure – Italian
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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 mini Series


Proton Products InteliSENS® SLR mini Series non-contact, bidirectional speed and length gauges provide extremely accurate speed and length measurements in almost any sheet material or converting application.

Production processes for web products, woven and non-woven materials, paper, plastic film, tapes, building materials, flooring 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 mini 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 – Laser surface velocimeter

Proton Products InteliSENS® SLR mini Series speed and length gauges illuminate the measured surface with an 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 mini 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.



SLR mini 1220
SLR mini 3060
Part number00050MC01100050MC012-
Stand-off distance120300mm
Maximum speed (bidirectional)20005000m/min
Internal measurement rate200kHz
Measurement output interval20µs
Laser spot diameter3mm
Operating temperature540°C
Ingress protectionIP67
Power supply152425VDC
Power consumption8W
*only valid if the measured object is positioned within the central 20% of the depth-of-field.


Measurement units
(end-user configurable)
Laser safety control inputsLaserExternal closed contact to ground enables laser diode.
ShutterExternal closed contact to ground opens laser shutter.
Shutter status outputElectricalN-channel MOSFET pull-down (for connection to user-supplied opto-isolated relay).
Maximum voltage: 30VDCMaximum current: 100mA
FunctionPulled to ground when laser shutter is open.
3×Logic inputs
(end-user configurable)
ElectricalMaximum input voltage: 24VDC
FunctionLength resetDisplay holdLength hold
Speed holdDirectionPause
2×Logic outputs
(end-user configurable)
ElectricalN-channel MOSFET pull-down (for connection to user-supplied opto-isolated relay).
Maximum voltage: 30VDCMaximum current: 100mA
FunctionGauge OKLaser at tempLaser on
MeasuringPreset Length 1Preset Length 2
2×Differential pair pulse outputs
(end-user configurable)
ElectricalOpto-isolated differential pair
Output voltage: 5V or user supplied (up to 24V)
Maximum frequency: 1MHz
FunctionIndependentQuadrature pair
CANbus communicationsConnects to an optional Proton Products CDi interface display unit
Serial communicationsRS-232
Ethernet communicationsModbus protocol
Optional communications (factory-installed, choice of one, replaces standard Ethernet interface)PROFIBUSEthernet/IPDeviceNET


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