This document@ which is a Technical Specification@ provides a technique of measurement and evaluation of ultrasound in liquids for use in cleaning devices and equipment. It specifies ? the cavitation measurement at 2@25 ?0 in the frequency range 20 kHz to 150 kHz@ and ? the cavitation measurement by extraction of broadband spectral components in the frequency range 10 kHz to 5 MHz. This document covers the measurement and evaluation of the cavitation@ but not its secondary effects (cleaning results@ sonochemical effects@ etc.).