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AkiraJunto
Guest
My friend is working on his thesis which is to measure concrete density by using ultrasonic wave. The wave's frequency is 50 kHz and the concrete is 15 cm thick. He calculates the density of the concrete by measuring how fast the wave propagates through the concrete. So, he emmits the wave on one side of the concrete and a receiver receives the wave on the other side of the concrete. The problem is the wave cannot penetrate the concrete. Can an ultrasonic wave really penetrate a concrete? How strong (in voltage) should the wave be to penetrate