Optimization of contact surface and water layer
Acoustic gas caracterisation in a uranium rod in a nuclear storage pool

The influence of the contact surface and the liquid layer is very important. Figure 6 shows the theoretical sensitivity loss as a function of thickness for different coupling liquids. It's clear that for coupling with water (the coupler in our application), the loss of sensitivity is significant between a 5 µm layer and a 20 µm layer. This effect is less significant for honey. There are even materials for which the effect is reversed.