We are doing a2d conversion from a homemade sensor (it is picking up noise at different times). The sensor is a emf detector, with center frequency at 10khz. The sensor is picking up noise at random intervals, even when we are not close to the source of the emf field. We noticed that as we touch the metal chassis, the noise goes away and the a2d conversion outputs the expected results.
We are using 10 bit conversion that varies from 0-200 when the noise is present. We have also verified the ouput of the sensor, it is rectified and it outputs values from 0 volts - 5 Volts
I would greatly appreciated any advice anyone may have regarding this... We are at a loss as to why this is happening.