# Calibration Problem in Piezoelectric sensor

Hello everyone,

I am using piezoelectric sensor (MEAS LDT0-028K) whose baseline voltage is 50mV/g. But it gives baseline voltage of 2400mV/g (without applying any Force on it). need help to calibrate it.

Photo of sensor is attached. Urgent & valuable help will be appreciated.

thanks.

How can you vibrate it without applying a force? Doesn't make sense. Note the sensitivity they quote is purely AC, any DC offset is ignored as its piezo electric.

Post the datasheet for the sensor, a diagram of how you have it connected (hand drawn, not Fritzing) and the code, using code tags.

I am attaching the datasheet of sensor.

More over, Sensor has two legs. one is attached with ground and other is attached at analog input pin of Arduino board.

I am telling you the code for it’s calibration.

int tmp=3300*piezoADC/1023; // actual board voltage is 3.3 but i multiplied 3300 in order to
//convert it in integer.

No, that won't work - its an inherently AC sensor, the DC value is basically meaningless.

That is not a force sensor. It is a vibration sensor and/or accelerometer.

You have to measure changes in the voltage, that is, take voltage measurements rapidly, and calculate the difference between measurements. The difference is roughly proportional to the instantaneous acceleration.

It might help if you tell us what you want to measure. Leo..

Hi, Did you put a 1MegOhm or 10MegOhm resistor across the output pins of the piezo. The piezo is a high impedance device and will receive interference from outside magnetic and electric fields. The 1MegOhm or 10MegOhm will help minimise this and remove any charged up DC offset.

Tom.. :)