| 摘要 |
PURPOSE:To measure pressure, particularly gas pressure with high accuracy by the beat signals of the oscillation frequencies of the 1st and 2nd crystal vibrators by bonding these two crystal vibrators on a supporting member having mutually independent recesses with said recesses being held hermetically closed. CONSTITUTION:A crystal vibrator holder 3, formed of the same stock as that of crystal vibrators 1, 2, are constituted to a shape having mutually independent circular recesses in its upper and lower portions. The crystal vibrators 1, 2 are bonded in such a manner as to hermetically close these recesses, thereby forming spaces 4 and 5. When the measuring gas pressure P1 is admitted into the space 4 through vent pipe 6 and a reference gas pressure, e.g., atmospheric pressure P2 is admitted into the space 8 through vent pipe 9, then the crystal vibrator 1 produces a frequency change owing to the differential pressure between the space 4 and space 8. On the other hand, no frequency change is produced in the crystal vibrator 2 because the spaces 5 and 8 are communicated by a vent hole 7, thus from the differential signals of the oscillation frequencies of both vibrators 1 and 2, the measuring gas pressure P1 may be measured. |
