Aptflex F28 for Anechoic Test Tank Linings
The NPL's acoustic absorber Aptflex F28 is designed as a lining for ultrasonic test tanks which are used to characterise acoustic output of medical ultrasonic equipment. This material is only available from Precision Acoustics.
Ultrasonic Tank Wall Linings
Acoustic output measurements or ultrasonic testing in general can be strongly affected by reflections or echoes from test tank walls. This is particularly true for long toneburst or continuous-wave ultrasonic applications. To overcome this, test tanks should be coated with linings which must be of low ultrasonic reflection yet highly absorbent to ultrasound. NPL's material has been designed specifically to meet this requirement. Its simple design, being a single layer, ensures that the material is the cost effective solution for coating large areas such as the walls of an ultrasonic test tank. Individual sheets can be joined together using Aptflex F41 Acoustics Putty.
Physical Specification
- based on a polyurethane rubber material
- single-ply nominally homogeneous layer
- thickness of tile: 10mm
- tile dimensions: 300mm by 300mm or 1200mm by 600mm
- material can be precision cut in various geometries to meet exact end-user requirements
- density of 1.01g/m3, is close to that of water
Acoustical Specification
high transmission loss, approximated by 30dB/cm/MHz
high echo-reduction, >22dB at 1MHz, degrading to <13dB at 10MHz
echo-reduction >18dB over frequency range 1-3MHz
Transmission loss at frequencies greater than 2MHz is in excess of 60dB. This exceeds the dynamic range of the measurement and hence no more detailed data is available.
