Linear Encoders are generally available in two types, absolute and incremental, and are defined by their position signals. Absolute linear encoders create a unique position signal that is available anywhere along travel with the exact position being read after power cycling. Incremental encoders do not generate a unique signal and is zeroed after power-down. They rely on another switch or encoder for initial reference.
When it comes to linear encoders, engineers look for important performance specifications including linear measurement range, counts per distance, and lines per distance. The linear measurement range is the full range of travel that can be encoded. Counts per distance determine the minimum linear position increment that can be distinguished. Lines per distance refers to the actual marks of the moving linear element being encoded.
Gurley offers two technologies for linear encoders: incremental and our patented Virtual Absolute(R) brand of scales. For more information on these offerings, please click on one of the selections detailed above (both true absolute and Virtual Absolute are detailed in the Rotary Absolute section). For general information on Virtual Absolute technology please visit www.virtualabsolute.com.
GPI LINEAR ENCODER SELECTION GUIDE
Note: For all incremental encoders, max. resolution is after 4x quadrature decode in the user's electronics