This routine allows you to run trigonometric level loops using a total station or digital level loops using a digital level. The raw data collected for a total station is slope distance, zenith angle and prism height. For digital levels, the file format is the same where the slope distance is the distance from the level reading, and the zenith angle is set to 90 degrees. The prism height is the level rod height reading.


The opening dialog is where you set up the level loop. If road files are used, an additional tab in the leveling measurement screen will be made available for entering station and offset data. To use a digital level instead of the current total station, click the upper right Select button and choose from the available options, which include Manual 3-Wire, Manual 1-Wire, Manual Digital Level and Sokkia SDL. Manual entry can also be done by choosing Manual Total Station on the EQUIP tab. 





After the loop has been opened or created, select OK to begin measuring. The first reading of the loop must be a benchmark (plus) reading to establish the instrument height. Enter the point ID or known benchmark elevation, the prism height (trig levels), and a description. Then press the Read icon or Enter to measure. Once the reading has been taken, select the Store icon to keep it. You can take as many readings on a single point in any face that you like. You can also review the readings, and disable any that you don't like prior to storing.







Once a benchmark (plus) reading has been taken and stored, the Minus Reading dialog will be shown. This dialog allows you to read the minus reading to a turning point (TP), benchmark (BM), sideshot (SS), or a sideshot on an alignment (STA). Turning points advance the setup while sideshots do not. A reading to the benchmark in the minus screen will end the loop.





Once the minus reading on a benchmark has been recorded, you can then process the loop using the Process icon. At any time during the loop, you can edit a reading using the edit icon. Once you've processed the loop, a Review File dialog will be displayed. At this point you can choose to save the report or proceed to the Processing Options screen.



The Processing Options screen allows you to update all existing points in the coordinate file with the leveled elevations. It also allows you to overwrite the point descriptions using what was entered during the level loop and will compute coordinates for any points that were defined by station and offset.



If you select the 1-Wire method of Leveling, the graphic below may be helpful in selecting the options to conduct a simple level loop:



You "+" to your "backsight" and you "-" up to your foresight, and you name the points as you go.  You start by referencing a benchmark, and you close the loop by referencing the starting point or a second benchmark.