Why should I choose a magnetic technology over an optical one?！

Magnetic encoders’ technology has evolved dramatically in the last 10 years. 
Starting with low accuracy applications, such as cranes, moving stairs or elevators, which required encoders to operate at harsh, dirty environments, the more advances suppliers can now offer linear scales accuracies of up to ±3µ/m or rotary accuracies of up to few seconds. With the ability to operate at very low temperatures and up to 125 Deg, as well as Mil grade shocks, vibration and accelerations, this technology is now a perfect fit for most applications that one would not consider few years ago. 
Even max resolutions are now much better. We are able to supply magnetic encoders with resolutions up to 20nm. 

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