Eltra magnetic shaft encoders


Magnetic shaft encoders are devices for displacement measuring of an object with magnetic principle of operation and solid with shaft.


  1. Magnetic incremental encoders
  2. Absolute magnetic solid shaft encoder
  3. Single-turn
  4. Multi-turn

Magnetic incremental encoders

Magnetic incremental encoders are very popular worldwide. This is achieved due to their simplicity and reliability at the same time. The incremental principle of action is based on measurement with a starting point. Before starting, the user must set a zero point for device. After that, the device will record how much the disk has moved, according to the start.

Eltra magnet incremental encoder type includes the following series:Eltra magnetic incremental encoder image EMI 40

  • EMI 40 A
  • EMI 63 A
  • EMI 63 D

EMI 40 A is a compact encoder designed to operate in the harshest production conditions. It has a painted aluminum housing and is able to work optimally at temperatures up to 100 C (or 212 F).

Its shaft is made of 1.4305 / AISI 303 and has a shaft with diameter of 4 or 6 mm. The device is fixed using a 20 mm clamping flange. Emi 40a has an outer diameter equal 42 mm and a total construction weight only 150 g. However, the overall design is very robust, as it has Separate chambers and IP64/66 rating.

EMI 63 also works according to magnetic principle. The encoder has a slightly larger outer diameter (63mm) and weight (350g). Its housing is made of aluminum EN-AW 2011 and has an IP64 or IP66 enclosure rating (depending on model).

Such device is available in two types. Their main difference is in the flange form. EMI 63 A has synchronous flange 31.75 and EMI 63 D have 31.75 centering flange. Its shaft is made of stainless steel and can be in 9.52 or 10 mm variations. The maximum series accuracy is 2048 ppr that is a good indicator for a magnetic sensor.

Absolute magnetic solid shaft encoder

Absolute type sensors have a special scale design. Disk contains marks with a unique value. This allows system to determine how far the rotor is shifted at any time during whole operation. At starting period there are no needs to set a starting point.

Absolute sensors are divided into two types: single-turn and multi-turn. Single-turn ones have single disk in their design and measure the displacement of an object just in one cycle. Multi-turn devices can operate with multiple cycles and have several disks.

The following series belong to absolute magnetic shaft eltra encoder:

  • EA 36 AEltar absolute magnetic encoder photo
  • EMA 50 A/B/BY
  • EML 50 A/B/BY
  • EAM 36 A
  • EAMW 58 B/C
  • EAMW 63 A/D


EA 36 A belongs to the family of singleturn sensors and is designed to work with small objects. It has a 6 mm shaft made of stainless steel. The main body is also made of stainless steel and has a degree of protection IP 67. The device is coupling using fixing flange with screw holes with a diameter of 28 mm. Such sensor works with an accuracy of 720 ppr using SSI electrical interface.

EMA 50 is a single-turn magnetic encoder with a high level of accuracy up to 8192 ppr. Encoder has a size of 50 mm and can be mounted in several ways, depending on the model. Models 50 A and 50 B are mounted using synchronous flange (25 and 30 respectively), and the 50 BY has an anodized 25 mm flange. The housing in all variations is made of aluminum, and their shaft is made of AISI 303 stainless steel.

EML 50 is an analogue magnetic singleturn encoder with solid shaft, which is capable of working with a 12-bit resolution. Flange options are the same as the previous series, and the shaft have dimensions in the range of 6-10 mm. The device has an active angle with step of 90 degrees, in range from 90 to 360, depending on the model.


EAM 36 A is a miniature absolute encoder with a magnetic operating principle. Its body has a size of 36 mm and its shaft is 6 mm. The device uses contactless measurement technologies Magnetic ASIC and Energy Harvesting. As an electrical interface, the sensor uses SSI with power supply up to 30 V DC. Single-turn resolution is in the range from 1 to 12 bit, and multi-turn resolution from 1 to 39 bit.

EAMW 58 B / C is a standard magnetic multi-turn sensor for general use. All models have a shaft and stainless steel housing. The sensor is coupling using a synchronous flange of 50 mm or a centering one of 31.75 mm. The shaft is available in sizes of 6 mm (EAMW 58 B) or 10 mm (EAMW 58 C).

EAMW 63 A/D is similar to the previous model, however it is fastened with a synchronous or centering flanges with 31.75 mm diameter. The shaft in all models of this type has a size of 9.52 mm and is made of AISI 303. The housing is made of AISI 420 stainless steel and is rated IP 67 cover from cover side and IP 65 from shaft side. The total maximum resolution of the series is 24 bit.

Brief conclusion: Eltra s.p.a. released magnetic encoders with a solid shaft of a wide variety of connection types and working principles. The customer will be able to choose both a single-turn and a multi-turn sensor of the presented type.

On our website eltra-encoder.eu you can find all series from article in the product catalog. . To find out the delivery conditions and stock availability, please contact our manager.


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