Differential Length Measurement

Measuring length differences non-contact and accurate

Length differences are often caused by the process. Reasons are drying, moisture input, thickness change, tensile stress change, curing and coating, chemical reactions or the production of bad goods or rejects. Such effects are also known as material elongation or material shrinkage, material waste or material loss. Whenever the material entering a process has a different length than the material obtained from the process, a differential length can be measured. A differential length measurement can be carried out using portable length measuring systems or with permanently installed measuring systems. For non-contact differential length measurement, ELOVIS offers the µSPEED laser encoder system, which can also consist of more than two measuring heads and can be evaluated via an existing machine controller, via PC or via a separate PLC. The advantage of using µSPEED laser encoder systems is that both the incoming and outgoing fabric can be measured with the same high measuring accuracy, even if the incoming and outgoing materials or measuring surfaces differ.

Typical materials where process-related difference lengths can occur:

  • Textiles, carpets
  • Nonwoven, nonwoven, fleece, felt
  • Film, foil, adhesive tapes
  • Plastic packaging
  • Composite materials, compounds
  • Profiles, hoses, strands
  • Metal sheet, steel, rolling steel

Machine types in which material length differences occur:

  • Finishing machines
  • Tenter frames, stenter frames
  • Dryers, heaters
  • Converting machines
  • Calendering machines
  • Laminating machines
  • Rolling, milling machines

Application Examples

Shrinkage Measurement in a Tenter Frame

Tentering applications involve driving the right material lead in the feed line to achieve the desired material prope...

Length Measurement of Nonwovens

Length measurement of nonwoven, felt and material with high thickness variance and different grammages with consisten...

Length Measurement of transparent Foil

Precise length measurement on transparent film and foil for the food indutry and optical films. Length measurement on...

Matching Products and Services

Length & Speed Measurement Systems

  • Non-contact length and speed measurement, optically by laser
  • Length and speed free of slippage, maintenance-free, permanently calibrated and accurately measured
  • The Laser-Encoder replaces tactile measurement via impeller, wheel, measurement roller, or machine drive
  • Measurement of agitated surfaces via laser-doppler surface velocimeter

ELOVIS Services

ELOVIS offers the following services for differential length measurement:

  • Advice on difference length and speed measurement
  • Measurement & calibration services
  • Help with length complaints of your customers
  • OEM sensor developments in the field of difference length and speed measurement

Always available for you:
Bernd Engelsdorf


Vincenz-Prießnitz-Straße 1
76131 Karlsruhe, Germany

T +49 721 933823-0
F +49 721 933823-23


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