A strategy for the development and standardisation of measurement methods for high power/cavitating ultrasound fields: Final project report.

This document presents the findings of a six month project completed on behalf of the DTI National Measurement System Policy Unit (NMSPU) by a consortium comprising the National Physical Laboratory (NPL) and the Institute of Sound and Vibration Research (ISVR), University of Southampton. The overall aim of the project was to assess the requirements for methods and standards for measuring high power/cavitating ultrasonic fields. Current progress made in this area of metrology has been reviewed during the project. In addition, through telephone interviews, four types of tailored questionnaires, and face-to-face discussions, over 70 users, manufacturers and academics working in the area of high power ultrasound have been contacted. This has yielded a considerable volume of information on the techniques currently being used and on the specific requirements for standardised methods, both now and in the future. Techniques in use have been critically appraised and prioritised in terms of their suitability for standardisation and their potential application in the remote and local sensing of high power ultrasonic fields. On the basis of the information gathered and the critical analyses completed during the project, a package of work is recommended to deal with the highest priority requirements in the field of ultrasonic cleaning. This involves the establishment of a reference ultrasonic cleaning bath in conjunction with the development of special sensors for monitoring acoustic field and cavitation characteristics. In the longer term, the other lines of approach to standardisation referred to in the report - applicable to medicine and sonochemistry - should also be considered.