Patent Number: 6,305,232

Title: Method of dry-calibrating vortex flow sensors

Abstract: To achieve accuracies of the order of 0.75% of the measured value, a digitized, two-dimensional overall image of a bluff body (7), of the internal surface of a measuring tube (2) in the area of the bluff body, of the two fixing zones (71, 72) of the bluff body, and of contour line (51) of the inlet end (5) of the measuring tube is generated by a high-resolution electronic camera (9) located in front of the measuring tube (2) on the axis (3) of this tube. The overall image is divided into three partial images. The first partial image contains only information about the inlet end (5) and the internal surface (4) of the measuring tube, the second contains only information about the bluff body (7) without the fixing zones (71, 72), and the third contains only information about the fixing zones. From shape information about the fixing zones (71, 72) and ideal information characteristic of the ideal shapes of the fixing zones, cross-correlation information is formed. In a neural network (22), all information and corresponding standard information derived from a plurality of wet calibrations are processed into calibration factor information and/or dimension information about the geometrical dimensions of the calibrated vortex sensor.

Inventors: Ohle; Frank (Steinen, DE), Bernet; Walter (Steinen, DE), Maul; Joachim (Weil am Rhein, DE)

Assignee: Endress + Hauser Flowtec AG

International Classification: G01F 1/32 (20060101); G01F 25/00 (20060101); G01F 001/32 ()

Expiration Date: 10/23/2018