Acoustic technology measures pressure or vacuum in containers with metal closures that do not have a measurable lid deflection. The sensor applies a “tap” to the top of each container lid using an electromagnetic pulse, exciting the closure. The lid vibrates at a natural resonant frequency “tone” based on internal pressure or vacuum. The resultant “tone” signal is sensed by a microphone. The Digital Signal Processor (DSP) produces a real-time signal spectrum and calculates the frequency of the “tone” for that lid which is then compared to user set limits. Containers with a frequency outside these limits are rejected.
A User Interface is required to operate the acoustic sensor. This sensor is compatible with the T550, T4000 HMI, and PRO Series Interfaces. Each TapTone User interface is capable of running multiple inspections simultaneously. Other leak, fill level, or vision sensors (model and user interface dependant) can be added with the acoustic sensor. Consult the Product Catalog for more information.