Title:
CRYSTAL VACUUM GAUGE
Document Type and Number:
Japanese Patent JPH01313728
Kind Code:
A
Abstract:
PURPOSE:To measure pressure from low one to ordinary one with one temperature sensitive crystal resonator by utilizing the temperature sensitive crystal resonator as a heat conductive type pressure sensor in a low pressure area and utilizing it as a viscous pressure sensor in a middle pressure to ordinary pressure area. CONSTITUTION:A heat source 8 is set near the temperature sensitive crystal resonator 1 having a negative temperature coefficient. Negative feedback is performed to a power supplied to the heat source 8 so that the frequency of said resonator 1 is kept constant. The oscillation frequency of said resonator 1 is converted into a voltage in a rectifier 9 and added to the voltage supplied to the heat source 8 in an adder 10. According to an output voltage from the adder 10, a meter 11 is driven and the voltage value can be known from the needle of the meter 11.
Inventors:
TAMURA FUJIO
Application Number:
JP14511288A
Publication Date:
December 19, 1989
Filing Date:
June 13, 1988
Export Citation:
Assignee:
SEIKO ELECTRONIC COMPONENTS
International Classes:
G01L21/10; G01L21/22; (IPC1-7): G01L21/10
Attorney, Agent or Firm:
Keinosuke Hayashi