Encoder tape by Eltra – the best magnetic linear encoder scale for long distances!

Encoder tape is the necessary part of linear encoder system for long distance measurements.Encoder-tape-image


  1. What is encoder tape?
  2. Eltra magnetic tapes

What is encoder tape?

The linear encoder tape is the measuring surface on which the encoder reading head travels. Its main purpose is to act as an external scale for the linear encoder. The main advantage of such method is ability to operate over very long distances (up to 50 m or even more) with high resolution.

As tape encoders, there are three categories of scales:

  • Incremental
  • Absolute
  • Combined

Incremental scale gives information about movement and speed relative to a reference mark (zero point).Incremental track with reference track encoder tapescheme

Absolute scale has a unique value for each mark and shows data about the so-called absolute position with high precision.

Some models contain a combination of these two types. In such cases, the strip has two scales. However, this design is not suitable for every case and sometimes it is better to choose a specific one.

Optical and magnetic tapesAbsolute scale with incremental scale encoder tape

Both optical and magnetic tapes for encoders are produced. They are designed respectively to work with optical or magnetic encoders.

In the optical versions, a scale is intended to reflect the light signal. In magnetic variants, it contains magnetic poles to interact via magnetic fields.

Magnetic scales are the most popular as they are not sensitive to pollution in industrial conditions. Optical scales, despite more accurate results and faster respond time, are very sensitive to contamination (dirt, liquids, oils, etc.)

The main advantage of using tapes opposed to common linear encoders is the operation at extremely long distances. For rotary encoders, there is also a special solution when a large diameter is required.

Eltra magnetic tapes

Eltra EBMA magnetic tape is specifically designed to work with incremental magnetic encoder ETMA.

General specificationsMagnetic encoder tape image

Such tape has 10 mm width and 1.66 mm height (1.43 without steel cover). With steel cover tape, its bending can reach up to 65 mm and 100 mm without it.

The length of the strip is on the range from 0,5 to 50 m. It works optimally at the temperature from -20° to 100 °C (-4 ... + 212° F). At subzero temperatures, moisture should be avoided. The products are fully certified according to the RoHs, CSQ-IQNet, and WEEE.

EBMA Main advantages:

  • Ease of installation (due to double-sided adhesive)
  • Two possible pole pitch variations (2 or 5 mm)
  • High pole accuracy (40 µm/m)
  • Standard length up to 50 m (available in reel)

Eltra ebma magnetic tapeEltra magnetic tape has a design that consists of three different layers. Each of them has its own special purpose. The scale uses incremental marks.

Flexible magnetic layer is a key element of entire work cycle. The magnetic poles are located here. Ferrite and nitrile rubber are used as the basic materials.

Stainless steel layer maintains the entire structure. It protects the mechanism from external substances and gives mechanical strength to the assembly. The additional function of such element is protection against external magnetic fluxes, which can distort the accuracy of the results. That strip already attached to the magnetic one.

Steel layer is the main external protection of magnetic part. It is placed above scale and protects against various harmful substances. It is need to attach it to magnetic tape at mounting. This part is a surface on which the position sensor head moves.

Thanks to its three-layer design, the tape works with high efficiency and protection class. It can be used for a wide variety of applications (motors feedback, CNC, industrial automation equipment, manufacturing machines, etc.).

The product is fully resistant to the following substances:

  • motor oil
  • break fluids
  • kerosene
  • salt spray
  • water
  • emulsion
  • mud
  • antifreeze

Attention! You should avoid getting aromatic hydrocarbons and mineral acids on the surface.

To get installation tips please check out our manual for EBMA.

On our website, you can find a wide range of encoders, software and tools for different applications. Our Company has an individual approach to each client's needs and pay maximum attention to solve it. Call now!

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