How the Therapeutic Ultrasound Intensity is measured?

One of the most popular method used to measure the ultrasound Intensity (power) is by the RFB (radiation Force balance) method. The sonic force emitted by the Ultrasound transducer probe exerts a force proportional to the radiated sonic energy when intercepted by a target. This force is proportional to the emitted power. The UPM 2000 consists of three major components, a precision load cell, a metal cone with 45 degree angle with 3 inch base and a water (degas) tank with rubber liner for absorbing the reflected sound energy. The cone immersed in the degas water act as the interceptor. The cone is mounted on a precision load cell for accurate measurement of the excreted force by the ultrasound waves. The measures force is computed to watts.