A distance measuring instrument (1) uses one or more start switches (3) and measures the distance to an object (T) in response to each start signal. The instrument (1) is linked to both a data storage system (2) and an evaluation device (4); these are linked to one another. Measurements within the distance range taken through the instrument (1) can be stored in the data storage system (2) and compared with subsequent measurements received at the evaluator (4). This is particularly useful if the measurements are of separate points. The distance comparisons made may be displayed on a screen (5) or transmitted through leads (6) to another system for further analysis.
