Title:
PRESSURE SENSOR AND GAS FLOWMETER USING THIS PRESSURE SENSOR
Document Type and Number:
Japanese Patent JPH04147015
Kind Code:
A
Abstract:
PURPOSE:To eliminate noise due to a sound pressure and to enable highly-precise detection of a pressure fluctuation by constructing first and second fluid pressure introduction channels and third and fourth fluid pressure introduction channels to be equal substantially in a length and a capacity. CONSTITUTION:First and second fluid pressure introduction channels 37 and 38, as well as third and fourth fluid pressure introduction channels 39 and 40, are constructed to be equal in a length and a capacity, respectively. As for two piezo-electric elements 2 and 3, accordingly, lengths between the opposite surfaces thereof and inlet nozzles 29 and 30 and capacities are equal respectively. The elements 2 and 3 are provided so that the opposite surfaces thereof face in the same direction respectively and that the surfaces in the same direction have the same polarization properties. Besides, the nozzle 29 communicates with the surfaces of the elements 2 and 3 being reverse in the polarization property to each other, through the channels 37 and 40, while the nozzle 30 communicates also with the surfaces of the elements 2 and 3 being reverse in the polarization property to each other, through the channels 38 and 39. By a sound pressure propagated, therefore, charges of the same amplitude are generated in the elements 2 and 3, a differential processing thereof is made, and thereby noise due to the sound pressure is removed automatically.
Inventors:
NAKANO NOBUKO
ITO TORU
KATO TOMIO
ITO TORU
KATO TOMIO
Application Number:
JP27098690A
Publication Date:
May 20, 1992
Filing Date:
October 09, 1990
Export Citation:
Assignee:
TORAY INDUSTRIES
International Classes:
G01F1/20; G01F1/32; (IPC1-7): G01F1/20; G01F1/32
Attorney, Agent or Firm:
Toshimitsu Ban