Structured Absorbing Lining for Low Frequency Ultrasonic Test Tanks
- based on a polyurethane rubber material
- single ply with structured surface to reduce the acoustic reflections
- thickness of tile: 50mm
- tile dimensions: 600 mm by 600 mm
- density of 2.1gm/ml +/–0.030
- weight of each tile 35kg
Transmission Loss (TL)
This limits or affects the performance at low frequencies, as TL goes down with frequency. At 100 kHz, the single-pass transmission loss of a 50mm thick layer of the material is 50 dB, which means that the double pass (where the wave which goes through the tile, bounces off the tank wall & comes back out) is 100 dB
The transmission loss increases rapidly with frequency in the following way: 20kHz 15 dB single pass; 100 kHz: 50 dB single pass; 200 kHz: 80 dB single pass.
This limits or affects the performance of the tank-wall lining. Below 200kHz, the ER is better than -30 dB.