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Precision Acoustics

Aptflex F28P

Pyramidal structured absorber for radiation force balance targets for acoustic power greater than 2 W but less than 100 W.

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aptflex f28p tile


NPL Technology AppliedThe combination of the acoustic and physical properties of the Aptflex F28P acoustic absorber makes it the cost-effective solution for a radiation force balance target for devices measuring acoustic power in the range 2 W to 100 W. 

Physical specification

  • Based on a polyurethane rubber material, single-ply nominally homogeneous layer
  • Pyramidal structured surface with maximum thickness of tiles: 8 mm
  • Tile dimensions: 200 mm X 250 mm x 10 mm
  • Coefficient of linear thermal expansion: 200 ppm/oC
  • Specific gravity is 1.01g/cm3 is close to that of water
  • Longitudinal wave speed (1 to 10 MHz) is ≈1500 m/s
  • Acoustic impedance is 1.5 MRayls
  • There is a resistance to Isopropyl Alcohol (IPA) and trichloroethylene
  • It can be affected by ketones (MEK, Acetone) which causes it to swell and dichloromethane which also cause swelling and break down
  • Avoid prolonged exposure to Ozone and UV
  • The stability of F28P is very stable due to cross-linked nature of polymer
  • The material can be cut with a sharp craft knife to make various geometries to meet exact end-user requirements

Acoustical specification

  • High insertion loss, approximated by 20 dB/cm/MHz.
  • High echo-reduction, greater than 42 dB at 1 MHz, to greater than 1 MHz to 20 MHz.