Skil ME981901 Owner's Manual page 22

NOTE:
The calculated length AC(a) defaults to be absolutely level
and lengths AC(a) and BC(b) default to form a right angle of 90°.
(FIG. 10)
Fig. 10
A
NOTE: When the tool inclines to left or right in any position, the
LCD screen will show "--.-°" or an inaccurate angle measurement in
first row of the display. Subsequent measurement will be showed or
calculated by error message or inaccurate value.
NOTE: When the laser is inactive for 20 seconds, it will
automatically turn off.
X
Fig. 11
M O D E
22
BAC
a
m
Indirect
B
b
M O D E
C
Indirect