Levelling staff for electronic levelling apparatus

摘要

The levelling staff (1) includes several bar markings (11) of a first set, which are arranged in a longitudinal direction parallel to each other. Width measurements of the several bar markings in the longitudinal direction are identical to each other. Relationships of divisions of corresponding adjacent bar markings are represented by integers. Value are permutated which are continuously selected out of a number sequence of the relationship of corresponding divisions. Each permutation varies, which is selected from any position of the number sequence. Preferably, the divisions are integer multiplications of the width measurement of the bar markings. The integer is a number equal to or more than two. A second set of bar markings for an auxiliary levelling staff can be provided.