|Line and area levelling|
In Example 4 a combined area and line levelling is shown. Several new points were measured as intermediate sights within a levelling distance from one instrument position. When noting the readings, pay attention to the correct sequence within an instrument position: First write down the backsight (= foresight of the previous instrument standpoint, here TP 2), then the intermediate sights and then the foresight (= backsight of the next following instrument position, here TP 3).
It should be mentioned though that points determined by means of an intermediate sight will not checked.