Title:
ELECTROMAGNETIC FLOWMETER
Document Type and Number:
Japanese Patent JPH04339217
Kind Code:
A
Abstract:
PURPOSE:To enable the computing of a flow rate with a range of cycle of a high frequency by computing a flow rate signal with a cycle of high frequency as base using a time constant, a low frequency and a high frequency amplitude of a differentiatial noise and a sampling data. CONSTITUTION:In a microprocessor (MPU) 19, a timing signal Ts2 is applied to an excitation circuit 15 and an excitation current If containing two kinds of frequencies... high an low... is applied to a measuring fluid Q as magnetic field through an excitation coil 14. When on a symmetry exists on the up stream and down stream sides with respect to a line aligning detection electrodes 11 and 12, low and high frequency differential noises are generated with respect to a noise electromotive force which is generated in a fluid Q between the electrodes 11 and 12. A voltage between the electrodes 11 and 12 is read into a memory of the MPU 19 through a differential amplifier 16, a sampling circuit 17 and an A/D converter 18. The MPU 19 uses a time constant, low and high frequency amplitudes of a differentiatial noise and a sampling data to compute a flow rate signal with the cycle of the high frequency.
Inventors:
TORIMARU TAKASHI
Application Number:
JP1215491A
Publication Date:
November 26, 1992
Filing Date:
February 01, 1991
Export Citation:
Assignee:
YOKOGAWA ELECTRIC CORP
International Classes:
G01F1/60; (IPC1-7): G01F1/60
Attorney, Agent or Firm:
Masayasu Watanabe