Comparing 3 types of linear encoders on the market
OPTICAL GLASS ENCODER

Optical glass scales are made of optical glass with aluminum outter profile , they are the most popular type of linear encoders nowadays .
PROS:
It is with higher accuracy than magnetic scales.
CONS:
It does not allow users to cut to length when you have the scales ordered.
MAGENTCI ENCODER

Magnetic scales however, are with extreamly long working life,because the read head and scale body are contact-less, and they are very flexible to users who needs customized size.
PROS:
It is with longer working life than optical glass scales .
CONS:
They are unfortunately not working as accurate as optical glass scales.
INDUCTIVE ENCODER

Inductive scales like NEWALL DRO, are with extramly high-level protection, it can be working under oil or water, it is ideal for the working site with too much oil and dust.
PROS:
High protection level,can be working under oil or water.
CONS:
They are higher in price compared with glass scales and magnetic scale.