Nuclear magnetic resonance flowmeter,申请号US19870056001-传众专利搜索

Nuclear magnetic resonance flowmeter

申请公布号：US4782295(A)

申请号：US19870056001

申请日期：1987.06.01

申请公布日期：1988.11.01

申请人：

LEW, HYOK S.

发明人：LEW, HYOK S.

分类号：G01F1/716;(IPC1-7):G01R33/20

主分类号：G01F1/716

摘要：This invention discloses a flowmeter measuring flow rates by means of magnetic tagging, which comprises a flow passage through a constant magnetic field over a sizable length wherein the constant magnetic field is perpendicular to the direction of the fluid flow; a combination of a radio frequency transmitter and coil generating a localized alternating magnetic field perpendicular to the constant magnetic field and oscillating at a resonance frequency known as the Larmor frequency, which alternating magnetic field locally superimposed to the constant magnetic field over a short section of the flow passage is imposed in pulses at variable intervals; and a combination of an antenna coil and radio frequency receiver receiving and analyzing the peaks of radio frequency electromagnetic radiation pulses emitted by the fluid moving through the flow passage. The peaks of the electromagnetic radiation pulses from the fluid produced by the alternating magnetic field applied in pulses are directly related to the velocity of the fluid flow and, consequently, the fluid velocity is determined as a function of the peak values of the radio frequency radiation pulses from the moving fluid wherein the interval between the pulses is a parameter.