Checkline MX-1 - Manual (Page 8)

Dakota Ultrasonics
4
The PRB-0 key is used to "zero" the MX-1 in much the same way that a
mechanical micrometer is zeroed. If the gauge is not zeroed correctly, all
of the measurements that the gauge makes may be in error by some fixed
value. Refer to page 11 for an explanation of this important procedure.
The IN/MM key is used to switch back and forth between English and
Metric units. This key may be used at any time, whether the gauge is
displaying a thickness (IN or MM) or a velocity value (IN/
µs or M/s).
The BACKLIGHT key switches the display backlight between three
available settings. OFF will be displayed when the backlight is switched
off. AUTO will be displayed when the backlight is set to automatic mode,
and ON will be displayed when the backlight is set to stay on. In the AUTO
setting, the backlight will illuminate when the M X-1 is actually making a
measurement.