Acoustic sensors for pump monitoring      
Even the smallest leakages on delivery valves of oscillating positive  displacement  pumps (e. g. piston pumps) can be detected by    measuring cavitation. The acoustic diagnostic device SITRANS  DA400 consists of
cavitation sensors and an analyzer unit which  supplies the sensors with electrical energy and detects, filters
and evaluates the measured signal and outputs an alarm signal on  exceeding a defined limit value.