Nondestructive Pressure Measurement in Vessels Using Rayleigh Waves and LCR Waves

In order to avoid the potential safety problems caused by applying traditional pressure measurement methods in vessels, a nondestructive pressure measurement method is presented. This method utilizes ultrasonic Rayleigh waves and critically refracted longitudinal waves (LCr waves). Considering the effect of pressure and temperature of the vessel on both the wave speed and the propagation distance of ultrasonic, a modified model of pressure measurement is deduced. Further, according to this model, a reference method for temperature compensation, without temperature measurement, is presented. The relationship between the reference transit time delay and pressure is established through this method. In our experiment, the reference method is applied to a nitrogen gas cylinder whose working pressure is 15 Mpa. Experimental results show that the reference transit time delay is proportional to pressure change. Comparison between the reference method and the commonly used temperature compensation method shows that the reference method yields better performance.