GB862891A - Fluid flow measurement - Google Patents

Abstract

862,891. Measuring fluid flow. CALl- FORNIA RESEARCH CORPORATION. Nov. 2.5, 1957, No. 36665/57. Class 69 (1). [Also in Group XL (b)] The rate of flow V of a fluid stream is determined by injecting a known quantity A of radioactive isotope material into the stream and obtaining the total number N of counts produced in a radiation detector positioned at a downstream point during the passage of the quantity A. Relative rates of flow can be determined from the relationship V α A/N which can be modified by a proportionality factor F determined by the detector response and the geometry of the system to enable the absolute rate of flow to be determined using the relationship V = FA/N. A known amount of radioactive material 15, Fig. 1, is injected into a fluid stream 11 at point 12 and the counting pulses produced in the Geiger-counter 23 are supplied to an integrating circuit 25 which totals the counts received during the passage of the injected isotope. The proportionality factor F is obtained using the arrangement indicated in Fig. 2, in which a section of pipe 30 similar to pipe 10 is filled with the fluid comprising the stream 11 and the counting rate of the detector 23 is noted when a known amount of the radioactive material 15 is introduced, F is then calculated in counts per unit time registered from one unit of radio-activity per unit volume of fluid. From the values obtained for A, N and F the rate of flow at point 12 may be determined. Automatic measurement of fluid flow rate can be arranged by periodically introducing the isotope into the stream. Figs. 4-7 (not shown) indicate the application of the arrangement to the measurement of fluid flow in branch pipes and streams.