Measuring the instrument height

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

• The top mark corresponds to the trunnion axis of the instrument.

• The bottom mark is 0.158 m (0.518 ft.) below the top mark. Measure the bottom mark to the top ridge of the mark.

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.

Alternatively, to obtain an accurate measurement to the top mark (Ih), you can manually measure the slope distance from the ground to the bottom mark (Hm). To calculate the total instrument height (Ih), insert the measured slope distance (Hm) into the formula below: