Magnetic linear encoder uses a magnetic reader head for analyzing changes in magnetic fluxes for displacement analysis. Its scale consists of a set of poles north and south that are magnetically coded. They are arranged in a specific way depending on the type of strip incremental or absolute. When a slider passes through each pole on the magnetic tape, the sensor reads current changes in the magnetic fields.
After that, the transducer compares all received data with the coded position. A sensing task usually performs by a Hall sensor. The main advantages of magnetic units are their reliability and non-contact way of working. It also has long service life, so it is most often used in harsh environmental conditions in contaminated and humid areas, etc. However, such units are quite sensitive to another magnetic interference. Optical linear encoder uses light beams or lasers as a signal.
To improve the quality and direction of light pulses additional elements are also installed into design lens, scanning reticles, etc. To do this, transparent clearance or opaque areas are placed on the scale as marks.
The optical scale is usually made from glass or plastic, sometimes from aluminum. Optical technology allows linear measurements with the greatest accuracy and high resolution. However, pollution or solid particles in a gap between measuring surface and sensor as well as mechanical shocks and vibration can significantly affect the accuracy. Therefore, such devices should be used in conditions with small risk of mechanical shocks and factors affecting the light signal.
Conclusion : Linear encoder is the best sensor for linear measure. So, what has more accurate feedback linear or rotary encoder? It all depends on the density of labels. The method of linear equipment operation is similar to rotary encoders, but instead of a wheel, they use a scale. The most suitable model is selected depending on the tasks and environmental conditions. We are Eltra encoder distributor and on our website you can buy low-cost Eltra linear encoders.
Despite the low price, they are reliable and have a long lifespan. Our managers will help you to pick a right encoder. Check out! Write your comment. How Does Linear Encoder Work? Collectively, the linear encoder is able to convert motion into digital or analog signals to determine the change in position over time. Now that we've examined how linear encoders work, we're ready to move on to the last part of the Easy Encoder Guide: Applications.
In the meantime, if you have any questions about using encoders or you're seeking consultation for your next project, contact our experienced staff for a free consultation. Topics: Controls. Welcome to ACD Connect! We will be bringing you the latest industry news in Industrial Automation, features on new products and manufacturers, helpful Engineering tips and how-to's, as well as exciting company updates. ACD Connect is where to go to read about the industry's newest technologies.
What is a Linear Encoder? How do Optical Linear Encoders Work? See Figure 6 This output signal frequency is proportional to the measuring speed and the displacement of the sensor.
Conclusion Now that we've examined how linear encoders work, we're ready to move on to the last part of the Easy Encoder Guide: Applications. Stay tuned for Part 4 of the Easy Encoder Guide! Search this site on Google Search Google. The EVOLUTE encoder communicates bi-directionally in purely serial format, using a variety of industry-standard protocols, of both proprietary and open standard.
The controller initiates operation by sending a demand message to the readhead, instructing it to capture the absolute position on the linear scale at that instant. Crucially its timing is controlled within a few nanoseconds to preserve the relationship between demanded and reported position, making the EVOLUTE series ideally suited for high specification motion systems. The absence of multiple parallel tracks gives important immunity from yaw errors and a higher lateral tolerance in head position.
The scale is imaged, via an aspheric lens which minimises distortion, onto a custom detector array. Once captured by the detector, the image is transferred via an analogue-to-digital converter to a powerful Digital Signal Processor DSP. After final error checking procedures, position information is uploaded in the appropriate protocol to the controller as a pure serial word.
QUANTiC encoders feature the third generation of Renishaw's unique filtering optics that average the contributions from many scale periods and effectively filter out non-periodic features such as dirt. The nominally square-wave scale pattern is also filtered to leave a pure sinusoidal fringe field at the detector.
Here, a multiple finger structure is employed, fine enough to produce photocurrents in the form of four symmetrically phased signals. These are combined to remove DC components and produce sine and cosine signal outputs with high spectral purity and low offset whilst maintaining bandwidth to beyond kHz. Interpolation is within the readhead, with fine resolution versions being further augmented by additional noise-reducing electronics to achieve jitter down to 2.
The IN-TRAC reference mark is fully-integrated in the incremental scale and is detected by a photodetector within the readhead. This unique arrangement also benefits from an automatic calibration routine that electronically phases the reference mark and optimises the incremental signals.
TONiC features the third generation of Renishaw's unique filtering optics that average the contributions from many scale periods and effectively filter out non-periodic features such as dirt. These are combined to remove DC components and produce sine and cosine signal outputs with high spectral purity and low offset while maintaining bandwidth to beyond kHz.
The IN-TRAC reference mark is fully-integrated in the incremental scale and is detected by a split photodetector within the readhead.
As the diagram shows, the reference mark split detector is embedded directly into the centre of the incremental channel linear photodiode array ensuring greater immunity from yaw-dephasing. Yielding a reference mark output that is bi-directionally repeatable to unit of resolution at all speeds. This unique arrangement also benefits from an automatic calibration routine that electronically phases the reference mark and optimises the dynamic signal conditioning.
The VIONiC encoder features the third generation of Renishaw's unique filtering optics that average the contributions from many scale periods and effectively filter out non-periodic features such as dirt.
Interpolation is within the readhead, with fine resolution versions being further augmented by additional noise-reducing electronics to achieve jitter of just 1. ATOM DX readheads feature a non-collimated LED light source located centrally between the incremental and reference mark sensors: this high divergence LED produces a low profile height with a footprint at the scale that is much larger than the LED, enabling illumination of incremental and reference mark regions.
The incoherent LED produces a signal of high harmonic purity allowing high resolution interpolation. Efficient photometry also produces an output signal with low jitter. A significant benefit of this filtering optics scheme is that ATOM DX does not generate measurement errors due to scale undulation or contamination. Digital signal interpolation is generated within the readhead, with fine resolution versions being further augmented by additional noise-reducing electronics to achieve jitter of just 1.
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