Abstract: In a rod extensometer for measuring movements in rock structures and in foundations, the measuring rod system consists of a one piece flexible rod made of reinforced plastic and surrounded by an encasing tube and connected at one end to a fixed-point anchoring device and by its other end to a pick-up element for the measuring value. This design enables the rod extensometer to be inserted into a borehole at short notice and with very little loss of time. Furthermore, the rod can form a practically endless structure wound onto a delivery spool and thus stored and transported with ease and in a space-saving manner.

Abstract: A dynamometer for measuring forces on an anchor in a building construction. The dynamometer has two closely spaced annular discs enclosing a pressure chamber between them. The discs fit around the head of an anchor between a fixed support and a fixing nut. The chamber between the discs contains pressure medium and in use is connected to a pressure gauge. At least one of the discs has flexible zones adjacent its inner and outer peripheries and the discs are otherwise of rigid construction.