Measuring and testing – Volume or rate of flow – By measuring electrical or magnetic properties
Patent
1997-04-04
1998-12-08
Oen, William L.
Measuring and testing
Volume or rate of flow
By measuring electrical or magnetic properties
G01F 158
Patent
active
058472860
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a magnetically inductive flow meter for flowing media with: a tube that is made of a ceramic material and used as a measuring line; a magnet for producing a magnetic field that runs at least essentially perpendicular to the axis of the tube, with at least two measurement electrodes arranged preferably perpendicular to the tube axis and preferably perpendicular to the direction of the magnetic field; and at least two shielding or screening electrodes that shield the measurement electrodes from outside electrical fields, wherein the measurement electrodes and the shielding or screening electrodes are placed outside the tube.
2. Description of The Related Art
The flow meter previously described is known from DE-A-33 37 151, from which this invention comes. In that flow meter, the measurement electrodes and the screening or shielding electrodes are placed galvanically on the surface of the ceramic tube. Because of this placement, the measurement electrode can only be shielded from the side. Now in order to make screening or shielding possible radially to the outside, DE-A-33 37 151 proposed attaching a ceramic supporting body in the area of the measurement electrode from the outside. This ceramic supporting body has screening or shielding electrodes on the surfaces that form the outer surface of the whole arrangement after the supporting body is placed on the tube and are also applied galvanically. In order to produce a tight connection between the ceramic supporting body and the tube with the measurement electrodes and the screening or shielding electrodes, the screening or shielding electrode placed on the ceramic supporting body is soldered to the screening or shielding electrode placed on the tube. The electrical signal that is produced by the measurement electrode is taken to the outside by a contact pin that runs through a hole in the ceramic supporting body. Provision is also made for the components of the preamplifier to connect directly to the screening or shielding electrodes arranged on the ceramic supporting body and the contact pin, which are, in turn, shielded by a screening or shielding box or cup attached to the supporting body from the outside.
The flow meter known from DE-A-33 37 151, now has various disadvantages. For one thing, it takes a large number of operational steps to produce the screening or shielding for the measurement electrodes. For this, the measurement electrodes and screening or shielding electrodes are first applied galvanically to the tube.
The ceramic supporting bodies are produced in a separate operation, and the screening or shielding electrodes are then placed on them by galvanization. Finally, the ceramic supporting body must be attached to the tube by soldering the screening or shielding electrodes on the tube on the outer edge of the contact surface to the screening or shielding electrodes on the supporting body. So it takes many operational steps to produce this arrangement of measurement and screening or shielding electrodes.
Another disadvantage of the known flow meter is that flaws can occur in the shielding of the measurement electrode, if the solder points are damaged by shaking, for example, and so holes can occur in the shielding. Another disadvantage of this flow meter is that having the ceramic supporting body and the screening or shielding box or cup attached to it makes the whole flow meter very high, and it cannot be designed compactly.
Another magnetically inductive flow meter known from DE-A-43 03 402 measures the flow speed of dielectric or electrically conductive media with a contactless capacitive pick-up. Since both the measurement electrodes and the screening or shielding electrodes are arranged on the outer surface of the tube, the screening or shielding electrodes can, because of this arrangement, only shield the measurement electrodes laterally, so that other measures are necessary to shield them radially to the outside. For this, DE-A-43 03 402 specifies that shieldi
REFERENCES:
patent: 4434666 (1984-03-01), Hemp et al.
patent: 4539853 (1985-09-01), Appel et al.
patent: 4631969 (1986-12-01), Scmoock
patent: 4658652 (1987-04-01), Picone et al.
patent: 5337607 (1994-08-01), Brown
patent: 5400659 (1995-03-01), Yokoi et al.
patent: 5544532 (1996-08-01), Brown
Dullenkopf Peter
Have Arnd ten
Klein Jurgen Winfried
Lenniger Andreas
Stratmann Andreas
Krohne Messtechnik GmbH & Co. KG
Oen William L.
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