Title:
FLOWMETER
Document Type and Number:
Japanese Patent JPH03134519
Kind Code:
A
Abstract:
PURPOSE:To make it possible to measure an accurate flow rate by generating current pulses based on the signal outputted from a temperature sensitive element when temperature rise is detected. CONSTITUTION:When fluid does not flow in a pipe 1, a heater 2 is heated with current pulses obtained by amplifying starting pulses from a starting-pulse generating circuit 15 in a pulse amplifier 11. Since the fluid is not moved, however, first and second thermistors 3 and 4 do not detect temperature change. An input signal into a differential amplifier 8 keeps the zero state. When a flow is generated in the direction of an arrow in this state, a warm point 14 in the fluid is generated by the application of the starting pulses on the heater 2 and moved leftward. The warm point 14 comes into contact with the thermistor 4, and a signal is inputted into the amplifier 8. Then, the amplified output is inputted into a pulse generating circuit 9. The generated pulses are amplified in a pulse amplifier 11 and applied to the heater 2. Then, the next warm point is generated in the fluid. A pulse train is generated from the circuit9 at a frequency corresponding to the magnitude of the flow speed. The frequency of the pulse train becomes a flow rate signal.
More Like This:
Inventors:
MIYOSHI NORIOMI
Application Number:
JP27150689A
Publication Date:
June 07, 1991
Filing Date:
October 20, 1989
Export Citation:
Assignee:
FUJI ELECTRIC CO LTD
International Classes:
G01F1/7084; (IPC1-7): G01F1/708
Attorney, Agent or Firm:
Namio Akio (1 person outside)
Previous Patent: HEAT-TYPE FLOW-RATE DETECTING APPARATUS
Next Patent: METHOD AND DEVICE FOR MEASURING AMOUNT OF TRANSPORTED BULK PRODUCT
Next Patent: METHOD AND DEVICE FOR MEASURING AMOUNT OF TRANSPORTED BULK PRODUCT