Title:
PIRANI GAUGE
Document Type and Number:
Japanese Patent JPH03255926
Kind Code:
A
Abstract:
PURPOSE:To reduce an error in pressure indication value by using the resistor in a Wheatstone bridge circuit on the side of its earth potential side and one of resistors connected between the ground and a constant voltage power source as a 1st and a 2nd temperature compensating resistance. CONSTITUTION:In the vacuum gauge having the Wheatstone bridge circuit equipped with a resistor R1(1), a filament R2(2), resistors R3(3) and R4, and an operational amplifier 6, the R3(3) is used as the 1st temperature compensating resistance, the line connecting the amplifier 6 and an input terminal 6b is branched halfway at the end of the resistor on the opposite side from the ground potential, and one of the resistors R5(9) and R6(10) connected between the ground and constant voltage power source is used as the 2nd temperature compensating resistance. The R3(3) operates to suppress an increase in the voltage V2 applied to the terminal 6a with the temperature of the outside air 7, so even if the temperature of the outside air 7 varies, the error in pressure indication value becomes small and pressure can stably be measured still with 10<-2>Pa.
Inventors:
KAKU AKIRA
NAKAMURA SHIZUO
NAKAMURA SHIZUO
Application Number:
JP5471290A
Publication Date:
November 14, 1991
Filing Date:
March 06, 1990
Export Citation:
Assignee:
ULVAC CORP
International Classes:
G01L21/12; (IPC1-7): G01L21/12
Domestic Patent References:
| JPS61240135A | 1986-10-25 | |||
| JPS63503085A | 1988-11-10 |
Attorney, Agent or Firm:
Yasuo Iisaka
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