Abstract: An electromagnetic flowmeter includes a metal case and a ceramic measuring pipe with a pair of coils and a pair of electrodes. The ceramic measuring pipe is a straight pipe or a pipe with flanges. The ceramic measuring pipe is detachably mounted in the metal case directly or through metal rings. O-rings are fluid-tightly mounted in flanges of the ceramic measuring pipe or the metal rings, respectively. A ground rod extends through a hole in the wall of the measuring pipe. One end of the ground rod is in contact with the conductive fluid and the other end thereof is electrically connected to the case through a screw or banana jack.

Abstract: An electromagnetic flowmeter uses a cylindrical inner tube including an electrode, an excitation coil and an inner portion of an electrical connector with the inner portion being located on an outer circumferential surface of the tube and electrically connected to the electrode and the coil, an outer tube housing the inner tube along its axis and having an access opening extending transversely through the outer tube housing and an electrical connector support externally inserted through the access opening for supporting an outer portion of the electrical connector to selectively mate with the first portion of the connector to provide separate electrically conductive paths through the connector for connections to the electrode and the excitation coil.

Abstract: Electrodes for an electromagnetic flow meter are mounted through a pipe wall using pairs of concentric electrodes electrically insulated from each other and from the mounting pipeline while electrically contacting a fluid in the pipeline being measured for flow rate. The electrode pairs are held on the pipeline wall on a line intersecting the fluid flow at a right angle and are electrically connected to supply signals induced by the fluid flow to a measuring circuit. The concentric electrode structure provides two electrode pairs at each electrode site on the pipeline wall.

Abstract: Electrodes for an electromagnetic flow meter are mounted through a pipe wall using pairs of concentric electrodes electrically insulated from each other and from the mounting pipeline while electrically contacting a fluid in the pipeline being measured for flow rate. The electrode pairs are held on the pipeline wall on a line intersecting the fluid flow at a right angle and are electrically connected to supply signals induced by the fluid flow to a measuring circuit. The concentric electrode structure provides two electrode pairs at each electrode site on the pipeline wall.

Abstract: An electromagnetic flow meter using pairs of concentric electrodes mounted through a pipe line in an opposed facing relationship. The output flow signals from the electrodes are first differentially amplified with respect to a common reference signal and then the output signals from the first differential amplification are differentially amplified in two successive operations to produce a final flow signal having a value "n" times the output signal from a single pair of "n" facing electrodes.