SYSTEM FOR POSITION MEASURING AND INTEGRITY MEASURING

摘要

A system for measuring the position of a rod element (3) as, for example, a hydraulically or pneumatically operated piston rod. Unlike the prior art, the system according to the present invention employs a measuring principle that does not require preparatory treatment of the rod element as is required in the known solutions. The system employs direct time of flight measurements with the aid of acoustic surface waves that are introduced into the rod element. The instrument is retrofittable on existing cylinders without any modification/ reconstruction thereof. An EMAT (6) principle is employed to introduce the surface waves into the measurement in a non-contact manner.