The The Ultra-Trak™ 750 shows the user an early warning signs of Mechanical failure, Valve leakage, Flow disruption and rcing by detecting changes of ultrasonic amplitude. The UE Ultra-Trak™ 750 Features, Demodulated Output for Analysis, Sensing Range 40 dB: Once the sound level is set, there is a 40 dB monitoring range and Outputs for External Data logging or Sound Recording. In some instances the Ultra-Trak™ can be used for sound level increases, such as to warn of onset of valve leakage or bearing failure. Housed in stainless steel, the rugged Ultra-Trak™ 750 is water resistant and dust proof, which means it can be externally mounted in some of the most challenging environments. Couple this with an extraordinarily wide dynamic range of 120 dB and sensitivity adjustment; this sensor is ready to meet your most demanding sensing needs.