Abstract: Improved drive means for oscillating the flow tubes of a parallel path Coriolis mass flow rate meter is described herein. The basic meter is known and comprises two substantially parallel flow tubes having oscillation axes and torsion axes. A pair of sensors sense the movement of the flow tubes about these axes with the time difference between the outputs of these sensors being indicative of the mass flow rate of the fluid. A drive means oscillates the tubes and comprises a coil and magnet-keeper arrangement. The present invention provides improved drive means comprising a rare earth-iron magnet having an annular configuration with a cup-shaped keeper member disposed thereabout to form an annular spacing. The magnet and keeper are affixed to the midpoint of one of the tubes. A coil is affixed to the other of the tubes with the coil interfitting into the annular spacing. The coil is so formed that the inductance does not exceed about nine millihenries.

Abstract: A method of brazing corrosion resistant, nickel-based, thin-walled tubing which includes substantial proportions of nickel, chromium and molybdenum to a stainless steel base member using a filler metal, principally comprising gold as a major constituent and nickel as a minor constituent, in a vacuum furnace without introducing stress corrosion cracks in the brazed tubing and also avoiding carbon precipitation. The brazing is conducted at a temperature of at least about 1900.degree. F. (1038.degree. C.) for a sufficient period of time to allow any carbide precipitation formed during the heating to redissolve and also to permit full, uniform flow of the filler metal. The heated members are rapidly quenched in an inert atmosphere to a temperature at least sufficiently low to avoid carbon precipitation in the tubing.