We can measure the attenuation and speed of sound in liquids and solids, typically over the frequency range 1 to 20 MHz. Solid or solid-like samples are normally required in the form of right-circular cylinders of diameter 50 mm and thickness 5 mm and above.

For liquid samples special liquid reference cells can be used for measurements which are made using an through transmission immersion technique by interposing the sample between a broadband hydrophone and transducer.

For measurements where the temperature variation are important, measurements can be carried out in the frequency range 5 °C to 50 °C.

For the most accurate measurement of speed-of sound, an ultrasound pulse-echo facility exists which monitors the change in arrival time of a reflected pulse when the distance between a transducer and polished reflector is accurately altered.

The technique is appropriate for application on relative small liquid volumes and, again, the temperature dependence of the speed of sound in liquids can be determined, with an uncertainty of typically ±0.01%.

Contact

Customer Service tel: +44 20 8943 8631
E-mail: acoustics_enquiries@npl.co.uk