SOWAN is instruments for the ultrasonic wave velocity measurement of rock samples. It is possible to read P and S wave propagation time with high accuracy, because it contains high voltage (500V) pulse and pulse width 1 ns. This instrument is for non-destructive test to obtain elastic properties of rock. By the input of length and density of rock, then it can calculate dynamic poisson’s ratio, shear modulus, young modulus etc. This instrument is useful for civil engineering and rock mechanic for rock-strength analysis and also geophysicist at oil company for rock physics analysis.