Thanks for replying Melanie,

The sensors output a 0-5vdc signal and are mounted about 5 feet away. Sample rates vary depending on user settings from 1 hz to 5 hz. A Filter would be a good idea but I'll have to figure out the values as I have no clue.

I still feel it's something different. It doesn't matter if sensors are hooked up or not, I still see the jumping. I run 20 conductor ribbon cable from the adc to the terminal board which is about 6" away. When I hook up the the terminal board, That is when the numbers start moving around (even without any sensors tied in).

As soon as I disconnect the ribbon cable, it all reads a steady zero.

Power supply, I see the small ringing in all wiring from the dc//dc converter. I've tried several including my 24 volt regulated bench top supply.

I agree, these items all need to be addressed, however, I have a question. If it it does it without sensors hooked up, then we know it's not noise from the sensors, so we can rule out the filter fixing it, although it's an excellent idea.

Next, if it were the power supply causing it, wouldn't I still see the flutter even when I disconnected from the terminal board?

Terminal board is a pretty simple board. PCLD-880, basically a row of screw connectors going straight to a 20 pin ribbon cable. The ground from the ADC goes to the terminal board as well. I have it tied to the sensor commons and to chassis ground.