Coriolis-type mass flow sensor

Abstract

This mass flow sensor, which can be mounted by means of end parts, in particular flanges, in a conduit of a given diameter through which flows a fluid to be measured, has two parallel, circular-arc-segment-shaped measuring tubes which are fixed at their ends in respective flanges. The measuring tubes have the same inner diameter D and the same wall thickness w. The circular-arc segment has a height h, an arc radius R, and a chord length L. The inner diameter D is chosen as a function of the maximum permissible pressure loss in the measuring tubes, and the wall thickness w as a function of the maximum permissible pressure of the fluid. The stress .sigma..sub.T resulting from a maximum permissible temperature change .delta.T of the fluid is chosen to be less than the .sigma..sub.0.2 -value of the material of the measuring tubes. Under these conditions and for a given arc radius R, the segment height h is chosen as small as possible to become h.sub.min. An external support tube is provided whose ends are fixed to the respective end parts. Means are provided for exciting the measuring tubes into opposite sympathetic vibrations perpendicular to the respective circular-arc plane, and means for sensing, at at least two points spaced along the measuring tubes, the vibrations of the measuring tubes.