Respuesta en frecuencia de un sensor o elemento Piezoeléctrico

Piezo transducers are usually specified for a single frequency to work on, for example 40 kHz(alta frecuencia).They have low sensitivity to other frequencies.

Frequency: 20 Hz - 20,000 Hz Audible

Frequency > 20,000 Hz Ultrasonidos (Entonces el piezo mide o captura Ultrasonidos ¿?).

A piezo crystal can be approximated well as a bandpass filter with a very tight pass-band and high impedance.

Respuesta ideal:

Respuesta real:

The frequency response of a piezo transducer can be altered by adding components like coils and resistor accross them. (piezo transducer detuning o efecto de carga)

Response with parallel resistor:

  • R(carga)=100Meg --> The bandwidth is approximately 0.5 kHz.

  • R (Carga)=1K --> bandwidth has only increased to approximately 1.5 kHz

Response with parallel coil and resistor:

  • L=8M y R= 8K -->The bandwidth has increased to 10 kHz