AVI Technology Acoustic Volume Indicator (AVI) technology, is a non-intrusive electronic technology which can determine the liquid volume in any pressurized metallic tank. This means it is now possible to determine the liquid level or gas pressure in an operating bladder or bladderless tank without shutting down the system or utilizing a weighing system which can be inefficient. AVI technology measures the resonant or natural frequency of the vessel. To optimize repeatability the program filters the excitation or ambient noise and monitors the “true” natural frequency, giving an accurate read of the liquid inside. It can be utilized in almost any application where there is a need to read the liquid contents of a metal tank. The AVI technology works with most liquid including water, fuel or sewage. AVI Data Sheet AVI Press Release See AVI Demonstration Order an AVI DVD AVI FAQs