公开(公告)号：EP3298359A1

公开(公告)日：2018-03-28

申请号：EP16718683.2

申请日：2016-04-26

申请人： Endress+Hauser Flowtec AG

发明人： PLOß, Peter ,  RUPITSCH, Stefan J. ,  BEZDEK, Michal ,  FRÖHLICH, Thomas ,  KISSLING, Beat

IPC分类号： G01F25/00 ,  G01F1/66 ,  G01F15/02

CPC分类号： G01F25/0007 ,  G01F1/662 ,  G01F1/667 ,  G01F15/024 ,  G01N29/12 ,  G01N2291/2634

摘要： A method for determining at least one pipe wall resonant frequency of a pipeline in the region of a measuring point by means of a field device from process measuring technology with at least one first ultrasonic transducer which is secured to the pipeline at the measuring point, comprising the following steps of: I) providing a first transfer function U
wandler (f) of at least the first ultrasonic transducer or of a plurality of ultrasonic transducers in the region of the measuring point; II) determining a receiving spectrum U
rec (f) from a reception signal u
rec (t) after an ultrasonic signal has been emitted; III) determining a second transfer function U
Messstelle (f) from the first transfer function U
wandler (f) of the first ultrasonic transducer or of the plurality of ultrasonic transducers and the receiving spectrum U
rec (f), wherein the second transfer function U
Messstelle (f) is characteristic of the measuring point; and IV) determining the at least one pipe wall resonant frequency f
res , in particular a plurality of resonant frequencies, in the region of the measuring point by evaluating the second transfer function U
Messstelle (f) from step III, and a clamp-on ultrasonic flowmeter, a method for determining a flow rate, a method for determining the change in the measuring point and an identification device.