Mounting definitions of Flush in Steel, Non-Flush on steel, and Non-metal
Flush in steel:
Active sensing surface can be flush mounted to surface of steel.
i.e. The sensing surface can be mounted on the surface of steel so that it is even with adjacent areas.
Non-flush on steel:
Active sensing surface must be clear and not be surrounded by steel.
i.e. The sensing surface must not be in contact or surrounded by steel.
The entire clear zone must remain free of any type of metal.
i.e. Total clearance zone from any kind of metal must be maintained.
To reach the specified read/write distance, the data carrier in the metallic environment must be mounted within a certain metal-free clear zone.