4.255 m
2.265 m
1.755 m
1.265 m
Formation level - Height of instrument
Formation level + height of instrument
Ground level + B.S
Ground level + F.S
Contour line
Profile
Contour gradient
Contour sections
Sight rail
Ranging rod
Offset rod
Boning rod
Sight rails and boning rods
Sight rail only
Boning rods only
Ranging rods