Method and device for measuring density and viscosity of high-temperature and high-pressure gas based on crystal oscillator

The invention discloses a method and a device for measuring density and viscosity of high-temperature and high-pressure gas based on a crystal oscillator. The method comprises the following steps: determining a test frequency and a detection temperature, obtaining a feedback voltage of gas at the test frequency based on a crystal oscillator, and obtaining a sweep frequency curve of the gas according to the test frequency and the feedback voltage; obtaining the resonant frequency and the quality factor of the crystal oscillator according to the sweep frequency curve of the gas; and constructing a viscosity density calculation model of the gas, and calculating the density and the viscosity of the gas according to the viscosity density calculation model of the gas, the detection temperature and the resonant frequency and the quality factor of the crystal oscillator. The tuning fork crystal oscillator is matched with the frequency synthesizer to detect the content of the high-temperature and high-pressure gas, so