Diameter measuring device for ground foundation or wall element has measuring element provided by rod-shaped profile with 2 concave strips pressed together for switching from flexible state to rigid state

摘要

The measuring device has a rod (10) and a measuring element (12) displaced in the direction of the ground foundation or wall element via the rod and having at least one rod-shaped profile (14) with 2 conditions exhibiting different flexure rigidities. The rod-shaped profile is provided by 2 curved flexible elongate strips coupled together with their concave sides facing and having a flexible condition in which the strips are separated from one another and a rigid condition in which the strips are pressed together via a deflection device (26).