Research Projects

Acoustical Resonance Spectroscopy

DIFFERENTIAL ACOUSTICAL RESONANCE SPECTROSCOPY (DARS)

Differential Acoustical Resonance Spectroscopy (DARS) exploits the low frequency resonance of a fluid column to measure the bulk acoustic properties of a small sample of rock and other material. First, we measure the resonant frequency spectrum of a fluid-filled but otherwise empty cavity. Next, we introduce a small sample of rock into the cavity and measure the changes in resonances, both frequency and Q. The changes are then inverted to estimate the modulus and Q of the sample. Example data are presented in the two figures below. The first figure illustrates the DARS concept. The second figure shows the results from a measurement of a 15-inch cavity with a small sample of Boise sandstone.