MEASURING SECTION FOR AN ELECTROMAGNETIC FLOWMETER AND A METHOD FOR THE MANUFACTURE THEREOF

摘要

A measuring section for an electromagnetic flowmeter is provided having a metallic measuring tube (2) made of a non-magnetic material, a set of magnetic coils for generating a magnetic field in a direction substantially at right angles to the direction of flow, an electrode arrangement which is arranged substantially at right angles to the direction of the magnetic field and substantially at right angles to the direction of flow, and an electrical insulator (11) on the inside of the measuring tube (2), and also a method for the manufacture of this measuring section. Here, it is desirable for manufacture to be carried out with a relatively high degree of reliability. For that purpose, the insulator is constituted by a surface layer (11) of metal oxide or metal nitride having a thickness of more than 10 mu m on the inside of the measuring tube (2). The inside of the measuring tube (2) can be oxidized or nitrogenized for that purpose and a metal oxide or a metal nitride is deposited on the resulting oxide or nitride layer (10).