| 摘要 |
PURPOSE: To perform the substantial compensation depending upon the temperature of a resonance frequency by combining with the output signal of a measured crystal and the output signal of a reference crystal. CONSTITUTION: Since the pressure of a hole 22 naturally depends upon temperature, the hole 22 preferably exhausts to certain degree, and hence the residual pressure becomes the response threshold or less of tuning fork type crystal. The substantial compensation depending upon the temperature of the resonance frequency can be performed in combination of the output signal of the measured crystal 11 and the output signal of a reference crystal 12. A series resistance is measured to correct the influence of the contamination during the measurement of the pressure, and the dependence of the temperature similarly to the contamination is ignored at the resonance frequency. On the other hand, the crystal 21 not exposed with the dirt since it is sealed with the region 22 by the same temperature characteristics as the crystal 11 to obtain the temperature and independent contamination compensation. |
