Improvement of the Dynamic Characteristics in the Connecting Passages for Measuring High Frequency Pressure Diagrams

Remarkable progress has been made in recent years on pressure measuring techniques and apparatuses, yet they seem not necessarily successful in achieving accurate pressure diagrams at the high frequency range. The primary cause of difficulty lies in the occurrence of undesirable vibrations in the connecting passages which diminishes the accuracy of pressure diagrams.

In order to prevent such vibration, the authors have attempted to increase the natural frequency in the connecting passages by enclosing heat resisting silicon oil, to analyse the frequency characteristics of the passages, and to ensure the propriety of the analysis through comparison with experiments.

As a result, it is proved that the natural frequency of the silicon oil enclosed passage increases twice as high as that of the passage filled with working gas. Moreover, this paper presents a method for correcting a deviation of the pressure diagrams caused by a failure condition where the natural frequency of the passage can not be enhanced.