Piezoelectric Sensor Frequency Response Calibration for Folding Boxboard Converting
Piezoelectric sensor frequency response calibration prevents amplitude distortion during high speed creasing by matching amplifier cutoff to rule strike transients.
High-Impedance Charge Mode
Electrical Configuration
Sensing systems that utilize piezoelectric transducers require a specific circuit design to capture the high-voltage signals generated during mechanical stress. Operating in high-impedance charge mode allows for the direct measurement of the electrical charge produced by the crystal without converting it to a voltage at the sensor. The configuration is standard for high-temperature applications where internal electronics would fail.
Signal Transfer
Special low-noise cables carry the signal from the sensor to a remote laboratory amplifier. Because high-impedance charge mode is extremely sensitive to electrical interference, the insulation of the cabling must be of high quality to prevent signal degradation. The amplifier converts the charge into a usable voltage for the data acquisition system.
This separation of the sensing element from the electronics allows for the testing of paperboard drying sections where heat and steam are present. High sensitivity is maintained over long cable lengths if the system is properly shielded. Technicians must ensure that all connectors are kept clean and dry to avoid leakage paths that would drain the signal.
Measurement Limitation
Static measurements are impossible in this state because the charge eventually leaks away through the insulation. Only dynamic events like impacts or vibrations can be recorded accurately. Frequency response is typically very wide, covering both low-speed shifts and high-speed shocks.