CTL has developed a directivity measurement system for the analysis of small to medium sized transducers. Aside from being useful as a transducer characterization tool, it has proven helpful in the diagnosis of problematic transducers and in the development of variable beam transducers.
At the 2012 UIA Conference in San Francisco, CTL presented the design as a low-cost directivity measurement system. You can find the poster here.
Figure 1: Transducer directivity measurement system (photo)
The system consists of a customizable mounting fixture for the device under test and a wide-band receiver. A programmable microcontroller and custom software interface are used to control the test parameters and automate testing. The mounting fixture was developed with portability in mind: tests can be performed in a small tank or the fixture can float in a body of water. The system functions in conjunction with standard laboratory equipment. A photo of the actual fixture can be seen below.
Accurate automated control makes results consistently reproducible. The figure below shows the user interface and a sample beam pattern.
Figure 2: User interface and sample beam pattern