AVI Video Demonstration Young Engineering & Mfg. has introduced its patented AVI Technology. The acoustic volume indicator, or AVI, measures the resonant or natural frequency of the vessel. It is a non-intrusive electronic technology, which can determine the liquid or gas volume in any metallic tank. This means it is now possible to determine the liquid volume or gas pressure in an operating tank without shutting down the system. For tanks with bladders, this means being able to determine gas or liquid volume without utilizing a weighing system, which can be cumbersome. To view Demo choose please click below by choosing the video size. Large Size (3.7MB file) Small Size (1.8MB file) To download Quicktime™ click here. To order the AVI DVD click here.