Measuring the instrument height

There are two measurement marks on the side of the instrument.

1 Top ridge of bottom mark 2 Top mark 3 Bottom mark

When there is a controller attached running a field application software, the software has additional functions that reduce the bottom mark measurement to the required vertical instrument height to the trunnion axis; refer to the image below and the following paragraph.

The measured distance (Hm) is corrected for the slope of the measurement to obtain a vertical measurement to the bottom mark (Hc). The constant from the bottom mark to the top mark (0.158 m/0.518 ft.) is added to the Hc to obtain the vertical instrument height from the ground mark to the trunnion axis (Ih). For more information, refer to the field software documentation.