| 摘要 |
PURPOSE:To avoid to be effected from other than gas or liquid pressure around an oscillator, by using a differential type oxcillation sensor consisting of a pair of oscillators receiving a pressure differentially. CONSTITUTION:A sensor S is provided with a pair of elastic body beams 2, 3 as oscillators incorporated with one beam for one end and fixed with a main body for another end, sticked with crystal piezoelectric substances 4, 5 having arranged characteristics, and when a pressure P as a process input is fed to the top junction, it is fed as a cross-mode input as expansion to one oscillator and compression to another. Two frequency signals f1, f2 from each oscillator are fed to a beat conversion BT and the signal difference f3 are input to the duty cycle modulation section DY and modulated, allowing to a signal only related to the cross mode input without being subject to the common mode input. |
