Interface Piezoelectric film sensor

[Thangadurai]

Hi,

In my project i need to monitor the pressure for that i am using the Piezo-electric Thin Film sensor(DT1-028K/L from Measurement Specialties) to sense the applied pressure. I dont how to use the piezo sensor because its changing its amplitude and frequency simultaneously when force is applied to the sensor i dont know how to measure the applied pressure using this sensor and how to set the analog input range for adc for this sensor.Please help me.....

 

[keith1200rs]

You will get noise pickup from the sensor and the signal will go positive and negative with the direction of the force applied. The voltage could be tiny or several volts depending on the force applied. What response speed do you want? I would start by using that as the starting point for some filtering to reduce noise pickup. I would be useful to arrange that the side exposed to the outside world is the grounded side of any amplification.

Keith.

 

[FvM]

its changing its amplitude and frequency simultaneously when force is applied to the sensor

Sounds like you don't know what you exactly want to do. To measure force or pressure with a piezoelectric sensor,
you should use a charge amplifier (respectively integrator).

Measuring the sensor voltage with a high impedance (GΩ range) buffer can work as well, but the lower cut-off frequency is then limited
by the sensor parallel resistance. You should also have an idea about the intended frequency range and keep in mind, that a
capacitive sensor can't measure DC values respectively static pressure. At best, a charge amplifier can be zeroed at times of
known zero pressure signal.

 

[karesz]

Hi,
This (non)understanding seems relative generous to be by piezos; i have had some "debate" with others over same subject too: ....
Other subjet for my un-understanding; why are the ppls lazy to read in textbooks_minimum in case of problems/ unconventionelle circuits-elements?:-(
K.