Acoustic solutions

Acoustic solutions for linear arrays

IMASONIC offers four types of standard acoustic designs for its linear array probes.

Versatile

The acoustic design is matched to the coupling medium (water, plexiglas, rexolite, etc.). The performances are slightly affected if the probe is used with another coupling medium. The design is optimized for both high sensitivity and damping in the range of 2.5 cycles (20dB) on average*. This technology has been proposed by Imasonic for several years.

Dynamic

The acoustic design is particularly optimized to gain about 6dB* sensitivity on average compared to versatile design, while keeping the same pulse length. This optimization is valid for the nominal coupling medium. When using the probe with other coupling media, performances degrade faster than the versatile technology

Accuracy

The acoustic design is particularly optimized to gain 0.5 to 1 cycle* in pulse duration on average compared to versatile design, while keeping the same sensitivity. This optimization is valid for the nominal coupling medium. When using the probe with other coupling media, performances degrade faster than the versatile technology

Hard face

The acoustic design is optimized to keep equivalent performance level than versatile design while implementing a front face 10 times* more wear resistant.

*The above mentioned values are indicative and may change depending on probes characteristics, particularly frequency, element size, acoustic matching, cable length,

How to choose ?

 

 

 

 

Bandwidth or pulse length?

 

The bandwidth of the probe is generally one of the main specifications. However, it is often specified instead of the pulse length.

When the bandwidth has a Gaussian shape, it is closely linked to the pulse length, and specifying the bandwidth is enough to get the pulse length. However, when the shape of the bandwidth is not Gaussian, as it is often the case, a rather long pulse is obtained, as well as a bandwidth of more than 100%.

Some applications really require bandwidth, for example, when the received signal is significantly shifted to the low frequencies due to the attenuation of the material, or for harmonic imaging.

Most applications actually require axial resolution using a short pulse length, and in this case it is more appropriate to specify the pulse length than the bandwidth.

In addition, the pulse length and bandwidth largely depend on the driving signal, the electrical impedance and the environment of the pulsers, which are not easy to simulate. This is why it is often difficult to predict these parameters with a high level of accuracy. Imasonic probes are optimized for and measured with a negative square pulse with the shortest possible fall time and rise time and a length of T/2.