Checkline MX-2 - Manual (Page 9)

MX-2 Ultrasonic Thickness Gauge
5
The MAT’L key is used to toggle through the 8 hard set and 2 user
programmed material types. When this key is pressed, the abbreviated
material name will be displayed followed by the material velocity for that
specific material. The 2 user defined material locations will display “Usr 1”
and “Usr 2” respectively. Note: The material velocities in the MX-2 are
approximate velocities only. Materials of the same type may have slightly
different material velocities introducing error into the overall measurement.
Note: The material types hard set in the MX-2 are listed by type,
abbreviation, and velocity on the back of the MX-2.