National Physical Laboratory

Ultrasound power output and Radiation Force Balance calibration

Reference balance 

NPL can measure the output power generated by transducers and reference sources, such as those produced by NIST and Precision Acoustics, to standard IEC 61161:

  • Over the range 1 mW to 20 W, between 1 MHz and 20 MHz, using radiation force balances
  • At HIFU levels (reaching over 300 W), typically between 1 MHz and 5 MHz, by the buoyancy change method based on the thermal expansion of castor oil

Power measurement devices can be calibrated for power levels up to:

  • 1 W by comparison with our Primary Standard Balance, for frequencies up to 25 MHz
  • 20 W by comparison with our Secondary Standard Balance, for frequencies up to 5 MHz


Customer Service tel: +44 20 8943 8631

Last Updated: 19 Mar 2013
Created: 5 Jun 2009


Please note that the information will not be divulged to third parties, or used without your permission