System for position measuring and integrity measuring

Register USPTO Patent
Application Number 14397800
Grant Number 09803664
Status In Force
Filing Date 2013-04-29
First Publication Date 2015-03-26
Publication Date 2015-03-26
Grant Date 2017-10-31
Owner TECHNI AS (Norway)
  • Petersen, David Christian
  • Bendiksen, Jan Martin
  • Schmedling, Petter F.
  • Karlsen, Morten Roll
  • Eisenträger, Roland
  • Kolle, Audun G.


A system for measuring the position of a rod element 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 principle is employed to introduce the surface waves into the measurement in a non-contact manner.

IPC Classes  ?

  • F15B 15/28 - Means for indicating the position, e.g. end of stroke
  • F15B 19/00 - Testing fluid-pressure actuator systems or apparatus, so far as not provided for elsewhere
  • G01D 5/48 - Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using wave or particle radiation means
  • G01S 15/02 - Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves